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The impacts of climate change pose a critical research challenge for sustainability. Despite growing awareness of green roofs as nature-based solutions, a significant gap exists in understanding their role in urban resilience. The research reviews thematic perspectives of green roofs in improving urban resilience. The paper used the PRISMA framework to systematically review the literature on green roofs and climate change, utilizing the keywords ''green roof*” and climate change'' in the Web of Science database. Bibliometric and thematic analysis is used to observe research trends from 123 publications that meet inclusion criteria, which include selected keywords, language, and publication type. Recurrent themes included urban heat islands, stormwater runoff, thermal comfort, biodiversity conservation, carbon footprint reduction, urban agriculture, and human well-being. The study proposes the Green Roof Resilience Framework (GRF), which combines these ideas into a systematic method for enhancing urban resilience. The research advocates for mainstreaming green roofs into adaptation planning, envisioning the creation of sustainable and resilient societies.

Abstract Lightweight aggregates are a material used in many industries. A huge amount of this material is used in construction and architecture. For the most part, lightweight construction aggregates are obtained from natural resources such as clay raw materials that have the ability to swell at high temperatures. Resources of these clays are limited and not available everywhere. Therefore, opportunities are being sought to produce lightweight artificial aggregates that have interesting performance characteristics due to their properties. For example, special preparation techniques can reduce or increase the water absorption of such an aggregate depending on the needs and application. The production of artificial lightweight aggregate using various types of waste materials is environmentally friendly as it reduces the depletion of natural resources. Therefore, this article proposes a method of obtaining artificial lightweight aggregate consolidated using two methods: drum and dynamic granulation. Hardening was achieved using combined methods: sintering and hydration, trying to maintain the highest possible porosity. Waste materials were used, such as dust from construction rubble and residues from the processing of PET bottles, as well as clay from the Bełchatów mine as a raw material accompanying the lignite overburden. High open porosity of the aggregates was achieved, above 30%, low apparent density of 1.23 g/cm3, low leachability of approximately 250 µS. The produced lightweight aggregates could ultimately be used in green roofs.

Buildings contribute to 40% of energy consumption and 30% of CO2 emissions in 2019 globally, therefore it is necessary to exploit different solutions to decrease the corresponding energy demand, including green and cool roofs as well as on-site energy generation. To evaluate the potential of such technologies, one major input data for models and calculations is the available roof area, yet the literature shows a huge knowledge gap in this regard. Therefore, this paper contributes to filling this gap by estimating the roof availability over the period 2022–2060, using the detailed regional projections of the BISE (Building Integrated Solar Energy) model. Our results show that the roof area is likely to increase globally and in most of the analysed regions over the forthcoming decades, driven primarily by newly built tertiary buildings. In European context, the future increase of commercial/public rooftops is projected to be more pronounced for the western countries, although the overall growth is predicted to be slightly offset by shrinking residential rooftops both in the western and eastern regions. This study also demonstrates that despite the shading-related uncertainties of the estimation, the dimension of the available rooftop area could ensure significant potential for energy production and thermal regulation.

This study examines existing buildings in Haikou in China under tropical island climate conditions. It presents three retrofit design models for greenhouses roofs (GHR), green roofs (GR) and photovoltaic roofs (PVR). The carbon cost of each retrofit roof model is calculated in the production and transportation phases of building materials, construction, and demolition. The changes in electricity consumption, water consumption, and plant carbon reduction are coupled to calculate the carbon reduction generated by each phase of the use of the retrofitted roofs. The carbon reduction per unit area for GHR, GR and PVR over the life cycle (20 years) is then comprehensively calculated. The life cycle carbon reduction per unit area is 262.57 kg·m−2 for GHR, 127.41 kg·m−2 for GR and 2567.12 kg·m−2 for PVR. Among the three retrofit methods, PVR has the greatest potential for reducing carbon emissions. The study can as a guide for implementing carbon reduction measures in tropical island areas. Domestic research on rooftop greenhouses also focuses on technology, yield, and energy consumption, mostly for northern regions with cold winters, and less research on rooftop greenhouses applied to regions with hot summers and warm winters. But domestic and foreign studies on the potential of rooftop greenhouses to reduce emissions have not yet been combined with plant cultivation of hydroelectric carbon emissions and plant carbon sequestration.

A closer look at the built environment shows that opportunities lie in transforming buildings with nature-based solutions for fostering climate resilience. To understand the potential of buildings in contributing to transforming cities, we conducted a systematic literature review to synthesize the evidence of the provided benefits of nature-based solutions implemented on their roofs and facades. Our goal is to highlight findings about the co-benefits of nature-based solutions on buildings in real-life case studies. After systematic screening and selection, the 222 reviewed research papers support that there is confidence in the climate resilience performance and benefits green walls, green roofs, and living walls provide, contributing to heat resilience and indirectly to social-ecological justice, especially when they are installed in old buildings. Our findings show that other recorded benefits include the provision of vegetation, habitat and biodiversity enhancement, and strong evidence of water retention and purification. We also report on design characteristics of nature-based solutions which are recommended when they are implemented on buildings. Green roofs were especially well-documented and it underlines the need of more studies about diverse NBS. From the synthesis of the state of the art, we propose that further research about the design of nature-based solutions on buildings is required to extend their co-benefits to noise reduction, air pollution entrapment and filtering, and carbon sequestration. In our paper, we found that the most important knowledge gap for future research is holistic perspectives on designing NBS on buildings.

The building envelope is the interface between the external atmospheric conditions and the indoor environment. It contributes to approximately 60%–70% of the heating and cooling load. The building envelope constitutes walls, fenestrations, and roofs from which thermal transfer from the roof is significantly very high compared to walls in low-rise buildings.This research paper aims to provide recommendations for energy-efficient roof design considering roof form, material, and external coating suitable for various climate conditions of India. The paper’s methodology consists of a literature review of related research papers, learnings from the roofing system of energy-efficient building case studies, and all possible energy-efficient roofing systems that would be simulated for energy efficiency and thermal comfort in five climate types of India. The expected outcome of this paper would be in the form of recommendations for roofing systems in different climate type and their potential for energy saving from the highest to the lowest. This research would be done in three stages viz, Step-1: Literature Review and case study of best practices: A review of the related literature and best practices examples would be done to formulate the maximum possible cases for the simulation. Step-2: The roofing systems, including building form, material (Thermal and insulation), and finishes (reflectance), would be simulated one by one for various climate types of India (composite, hot & dry, warm and humid, moderate and cold) to optimize energy efficiency and payback period. Step-3: Special roof types like Green roofs, cool roofs, Photovoltaic roofs, roof ponds, and the like are simulated and compared for their effectiveness in selected climate types. Based on the literature review, simulation results, and analysis, the recommendations are framed for energy-efficient roofing systems in the selected climate type with respect to heat transfer through the roof and thermal comfort.

Buildings account for a significant amount of energy consumption and greenhouse gas emissions worldwide. Electricity and fossil fuels are currently the primary sources of energy used for cooling and heating buildings, depending on the climate and location. Both energy sources are responsible for significant greenhouse gas emissions. In contrast, plants and vegetation absorb carbon dioxide and, thus, improve the quality of air. This effect indirectly influences climate change to lower energy demands and produce additional emissions due to rising energy consumption trends. Plants also reduce the ambient temperature by providing shade on roof surfaces. Hence, the large-scale deployment of green roofs reduces energy consumption, emissions, and costs. However, green roofs also impact the overall weight of a building and require additional construction costs. Therefore, the contribution of green roofs to the various structural and thermal performances of buildings varies for extensive intensive or semi-intensive systems. These interactions warranted a lifecycle analysis to optimize the extent of green roof applications. This approach highlighted sustainability performance measures, including energy, emissions, water, and waste. The presented study addressed a lifecycle analysis of green roof deployment during a hot summer in a Mediterranean climate zone. This climate applies to many areas that benefit from warming temperatures without extreme needs for cooling or heating. The emphasis on comparing two towns within the same climate zone facilitated a more detail-oriented approach to the lifecycle analysis. The results illustrated the energy consumption and associated release of greenhouse gas emissions related to structural and roofing materials and thermal operations throughout the service life of a building. The conclusions assessed the challenges and opportunities of green roof applications on new and existing buildings.

Abstract Cool materials and rooftop vegetation help achieve urban heating mitigation as they can reduce building cooling demands. This study assesses the cooling potential of different mitigation technologies using Weather Research and Forecasting (WRF)- taking case of a tropical coastal climate in the Kolkata Metropolitan Area. The model was validated using data from six meteorological sites. The cooling potential of eight mitigation scenarios was evaluated for: three cool roofs, four green roofs, and their combination (cool-city). The sensible heat, latent heat, heat storage, 2-m ambient temperature, surface temperature, air temperature, roof temperature, and urban canopy temperature was calculated. The effects on the urban boundary layer were also investigated. The different scenarios reduced the daytime temperature of various urban components, and the effect varied nearly linearly with increasing albedo and green roof fractions. For example, the maximum ambient temperature decreased by 3.6 °C, 0.9 °C, and 1.4 °C for a cool roof with 85% albedo, 100% rooftop vegetation, and their combination. The cost of different mitigation scenarios was assumed to depend on the construction options, location, and market prices. The potential for price per square meter and corresponding temperature decreased was related to one another. Recognizing the complex relationship between scenarios and construction options, the reduction in the maximum and minimum temperature across different cool and green roof cases were used for developing the cost estimates. This estimate thus attempted a summary of the price per degree of cooling for the different potential technologies. Higher green fraction, cool materials, and their combination generally reduced winds and enhanced buoyancy. The surface changes alter the lower atmospheric dynamics such as low-level vertical mixing and a shallower boundary layer and weakened horizontal convective rolls during afternoon hours. Although cool materials offer the highest temperature reductions, the cooling resulting from its combination and a green roof strategy could mitigate or reverse the summertime heat island effect. The results highlight the possibilities for heat mitigation and offer insight into the different strategies and costs for mitigating the urban heating and cooling demands.

IntroductionThe objectives of this study are twofold. The first is to identify potential green infrastructure construction sites by building rooftops and sidewalks. The second is to analyze internal flooding for a wide range of drainage areas and to quantitatively evaluate the effectiveness of stormwater runoff control.MethodsThe target area has approximately 600 ha with a runoff coefficient of 0.71. Using Arc GIS Desktop 10.8.1, this study has identified green roofs and bioswales that would be highly beneficial in capturing large amounts of rainfall. In addition, Info Works ICM was used for the inundation analysis, which can simultaneously calculate the flow in sewer pipelines and above-ground inundation flow. Runoff coefficients were calculated for each land use using the urban land use subdivision mesh data with 100 m unit. This study targeted a 10-year probability rainfall (total rainfall: 86.3 mm, maximum hourly rainfall: 52.3 mm/h, duration: 3 h) with a middle concentrated rainfall waveform obtained from past experiments in the d4PDF database of ensemble climate prediction contributing to global warming.ResultsThe amount of land availability for green roofs and bioswales was about 1 and 0.1% of the drainage area, respectively. The runoff coefficients for green roofs only, bioswales only, with and without introduction of both green roofs and bioswales were 70.34, 70.87, 70.28, and 70.93%, respectively. The difference in runoff coefficients was about 0.65 percentage points even when both were constructed. As a result of inundation analysis, the reduction was 2.5% for the maximum waterlogged area, 1.5% for the flooded area, and 0.7% for the average depth of waterlogging divided by the maximum waterlogged area. The construction of green roofs and bioswales in the same area or downstream of the area shows little mitigation effect when flooding occurs in an area near the downstream end of the sewer network.DiscussionAlthough this study has mainly discussed the stormwater runoff control aspect, the most important feature of green infrastructure is its multifunctionality. In terms of utilizing and promoting green infrastructure, it is important to visualize its multifaceted effects and share them with many stakeholders.

Green roofs are becoming popular in urban areas due to their potential benefits, including energy efficiency, urban heat island mitigation, and stormwater management. However, their water consumption can negatively impact water resources. Therefore, carefully managing the water consumption of green roofs is crucial to ensure they do not exacerbate existing water scarcity issues. This review explores the influencing factors and innovative solutions that increase the sustainability of water management on green roofs. A systematic quantitative review was conducted on published studies on green roofs. The review highlighted that while small-scale experimental studies are almost saturated, large-scale monitoring studies are still lacking. Modelling and assessing green roof settings based on climatic conditions and water availability and consumption are essential for successful water management. Using integrated technologies and sensing systems can increase water management efficiency and sustainability. Rainwater may be sufficient as a water source for green roofs in wet climates, while irrigation is still needed in other climates. Phytoremediation and biosorption can potentially increase runoff water quality. Improving hydrological performance by increasing rainwater retention and reducing water consumption capacity can reduce demand for other water resources and effectively manage small storms, mitigating pressure on city infrastructure and increasing water quality. Seeking non-potable sources, such as greywater, or harvesting enough rainwater to be used for irrigation during dry weather periods is highly advantageous for improving the sustainability of green roofs.

Residential buildings are the major sector in the construction industry that consume energy and affect the whole environment. Controlling these effects has always been the foremost concern, especially the existing ones. This paper addresses a case study of existing residential buildings at Jubail Industrial City in the Kingdom of Saudi Arabia, where the units are reproduced all over the districts.With proper design and maintenance, green roofs can provide cost-effective and sustainable solutions for existing residential buildings. The best set of strategies through the Climate Consultant software have been studied where the strategy of adding the green roof comes as a priority for the selected city. Green roofs, also known as vegetated roofs or rooftop gardens, offer a wide range of benefits for existing residential buildings. These benefits include improved insulation, reduction of stormwater runoff, increased biodiversity, and improved air quality. In addition, green roofs can also provide aesthetic and recreational benefits for residents. Green roofs can reduce a building’s energy consumption, lower urban heat island effects, and extend the roof's life.By using the green roofs suitable type for the existing buildings and simulating the two scenarios for the existing and the proposed cases using the Design Builder software, while using Climate Consultant software recommends strategies, results revealed that the green roof option could reduce the total energy consumption by at least 8.8 %. Besides benefiting the building's users, this approach will provide an economical solution to protect the environment in terms of reducing power consumption and environmental pollution.

With the advance of urbanisation many cities are confronted with environmental problems including air pollution, the absence of green spaces and urban heat island effects. The expansion of green infrastructure is viewed as an important aspect of urban sustainability agendas. One dimension of green infrastructure is green roofs. The objective in this article is to examine the development and challenges of green roofs in South Africa, presenting the results of a survey of the suppliers of green roofs. The findings show for South Africa the relative underdevelopment of green roof systems, the geographical unevenness of such developments and the challenges that confront the emergence of green roof systems in the South African context. Key issues relate to current high costs associated with green roof construction, absence of government support in the form of financial incentives, and lack of awareness of the sustainability benefits of green roof systems.

Global environmental and health issues such as climate change and the COVID-19 pandemic have highlighted the weaknesses of current urban systems, including the poor availability and accessibility of green and public spaces in cities. Nature-based Solutions are configured as promising solutions to increase the resilience and health of the built environment by addressing climate and pandemic issues, promoting the psycho-physical well-being of users and proposing solutions for the protection of the environment and ecosystems. Following a systematic review of the scientific literature using the PRISMA methodology, this study aims to provide a taxonomic framework for Nature-based Solutions for the built environment that is applicable to the urban and building scales, highlighting key benefits in addressing pandemic and climate challenges and achieving urban resilience. This framework proposes a holistic and multifunctional approach that will prove to be a useful tool for researchers and policy makers to incorporate greening strategies into urban regeneration and redevelopment processes. The application of Nature-based Solutions still seems to be limited. It is therefore necessary to raise awareness of this issue among citizens and policy makers and to promote close co-operation between the different actors in territorial decision-making processes.

Green roofs (GRs) are a widely recognized green infrastructure (GI) strategy that helps reduce runoff volume and runoff pollution caused by the significant increase in impervious urban areas. However, the leaching of several nutrients from GR substrates is a growing concern. Biochar, a carbon-rich material, possesses advantageous properties that can help address such environmental challenges associated with GRs. Therefore, this paper aimed to undertake a field study to investigate the impacts of various biochar application methods, particle sizes, and amendment rates on the quality of runoff from GRs. Observational data of runoff quality were collected over a two-month period from five newly established 1 m × 1 m biochar-amended GR test beds and a control test bed without biochar, with all test beds subjected to artificially simulated rainfall. The results indicated that the addition of biochar did not result in a significant improvement in runoff pH, whereas the electrical conductivity (EC) was higher in runoff from GRs with biochar-amended substrates. When comparing the total nitrogen (TN) concentration in runoff from the non-biochar GR (ranging from 3.7 to 31 mg/L), all biochar test beds exhibited higher TN release (4.8 to 58 mg/L), except for the bed where medium biochar particles were applied at the bottom of the substrate (ranging from 2.2 to 21 mg/L). Additionally, all biochar-amended GRs exhibited higher TP concentrations in runoff (0.81 to 2.41 mg/L) when compared to the control GR (0.35 to 0.67 mg/L). Among the different biochar setups, GR with fine biochar particles applied to the surface of the substrate had the poorest performance in improving runoff water quality. Despite these mixed results, biochar holds significant potential to improve runoff quality by significantly increasing water retention, thereby reducing pollutant loads.

The rise in outdoor temperatures and heatwaves highlights the limitations of buildings in adapting to warming conditions, even in temperate climates. This paper analyses the indoor overheating of residential dwellings in Pamplona (a city in northern Spain, with a Cfb climate) using an urban-scale diagnostic methodology and presents different envelopes’ retrofitting scenarios as a strategy to reduce it. The results come from energy simulations conducted during an extremely warm summer in 2022, considering the microclimate effects. The residential typologies most vulnerable to overheating are those with only one orientation, built before the EPBD 2002, and located on top floors. These dwellings show a 23.7% mean of indoor overheating hours (IOH), representing approximately 870 h above the EN 16798-1:2019 adaptive threshold from May to September. Renovating building envelopes to meet current energy standards reduces the IOH by an average of 8.6% and up to 15.35% in the most vulnerable typologies. In the retrofitting scenario with green roof systems, indoor temperatures are up to 0.5 °C lower than when roofs are renovated with traditional systems. This study assists policy-makers in preventing the risk of overheating within cities and encourages them to promote nature-based solutions in order to adapt urban residential buildings and cities to warming conditions.

As a sustainable approach to urban environmental management, green roofs are becoming more and more popular. They have been discovered to help reduce the urban heat island effect, insulating against noise and heat, managing stormwater, and eventually reducing climate change. Despite its established advantages and widespread use in most developed countries, green roofs have just recently gained popularity in the Izmir building sector. Izmir, a fast-growing city that may profit from green roofs, seems to have little idea of its potential. This study aims to determine the barriers to the widespread adoption of green roofs in Izmir. For this purpose, qualitative research was carried out and semi-structured interviews with government officials from different backgrounds such as architecture, landscape architecture, urban planning, and engineering were carried out to gather the primary data. Although there are prospects for the adoption of green roofs, the study revealed that these roofs are not common in the study region due to expense, technical difficulties, a lack of understanding, and standards. In light of this, it was also discovered that for the local sector to progress, government authorities must provide incentives and change regulatory settings to better promote the use of green roofs, while industry organizations must offer educational initiatives. Moreover, it is crucial to enhance technicalproficiency and conduct research related to green roofs’ proven benefits in the context of Izmir.

The urban growth leads cities to adopt sustainable strategies in order to mitigate the relevant hydrological effects. In this study, the use of synthetic aperture radar SAR imagery has allowed us to demonstrate a 70% increase of the built-up area in Sarno River basin between 1995 and 2016. This increase is linked to the statistical temporal increase of the damaging hydrological events occurring during the same period. To restore the pre-development hydrological condition, a scenario analysis was undertaken where SWMM was used to simulate the hydrological effect of green roof retrofitting landscape design. SAR imagery was furthermore used to explore the potential retrofitting surfaces, leading to defining three different conversion scenarios with 5%, 30% and 100% of potential retrofitting surfaces. The study demonstrated that the pre-development hydrological condition can be never fully restored. Indeed, this scenario is partially equaled only by a 100% green conversion of the existing traditional roofs, with average runoff and peak flow reduction of 41% and 25%, respectively. Such conditions are clearly not feasible, provided the obvious retrofitting limitation for existing buildings. The use of additional nature-based techniques, beyond green roofs conversion, should be explored in the perspective of a balance for urban growth. HIGHLIGHTS In Sarno River basin, a correlation between the increase of built-up areas and damaging hydrological effects exists.; Radar images help to identify the potential areas for green roof retrofit.; Green roofs applied at a basin scale allow substantial mitigation of urban runoff.;

Green roofs contribute to more sustainable cities, but current commercial substrates suffer from important limitations. If carefully selected, biochar could serve as a viable option for a more sustainable green roof substrate. We propose a protocol to select an optimal biochar for green roof substrate amendment. Coffee husks, medium-density fiberboard, palm date fronds, and a mixture of waste wood, tree bark, and olive stone kernels are selected as residues for biochar production to develop a selection protocol. The residues are pyrolyzed at 350, 450, 500, and 550 °C in a lab-scale reactor. A pyrolysis temperature of 450 °C is selected for upscaling and is based on biochar yield, pH, salinity, and elemental composition. From evaluating the biochar characteristics after upscaling, it can be concluded that the biochar’s carbonization degree is mainly controlled by pyrolysis temperature, while yield, pH, and salinity are more dependent on the biomass properties. Ultimately, our procedure evaluates the presence of important contaminants, the biochar’s water holding capacity, salinity, pH, and carbonization degree. To validate the developed protocol, plant coverage experiments on green roofs are performed, which are quantified using a novel digital image processing method, demonstrating its efficient use to facilitate future biochar selection in substrates.

This study investigates how permeable and cool pavements, green roofs, and living walls affect microclimatic conditions and buildings’ energy consumption in an arid urban setting: Shiraz. The study aims to evaluate the role of green infrastructure in mitigating urban heat island effects and enhancing outdoor conditions. By utilizing environmental modeling tools, specifically the ENVI-met 5.1.1 and Design Builder 7.0.2 software, a comprehensive analysis was conducted across various scenarios during both the summer and winter seasons. The results show that permeable pavements with 80% grass coverage reduced the mean average air temperature by 1.18 °C in summer mornings compared to the reference case. In both the summer and winter scenarios, the living wall intervention consistently emerged as the most effective strategy, showcasing substantial reductions in cooling consumption, CO2 emissions, and electricity consumption. With a 25% reduction in cooling consumption, a 14.7% decrease in CO2 emissions, and an impressive 53.4% decline in electricity consumption, the living wall excelled in its environmental impact, and it stands out for its substantial electricity savings. While the green roof and permeable pavement scenarios demonstrated more modest gains, their integration could offer a synergistic solution, warranting further exploration for optimized energy efficiency and environmental sustainability. These findings indicate the intrinsic connection between sustainable landscaping strategies and their influence on urban microclimate and building energy efficiency.

Green roofs have been widely recognized as sustainable nature-based solutions to mitigate floods in urban areas, which, in the last decades, are increasing due to the combination of intense worldwide urbanization and climate change. Besides flood mitigation, green roofs provide additional benefits for the urban environment (e.g., reducing the urban heat island and ensuring energy saving for the underneath building). Moreover, green roofs facilitate the increase of urban biodiversity, attracting different species of small animals, and upgrade the city aesthetic value. Among the different types of green roofs, multilayer blue-green roofs present an additional layer to store water during rainfall events. As part of the Polder Roof field lab project, prototypes of multilayer blue-green roof developed by the Dutch company Metropolder were installed in four Italian cities: Cagliari, Palermo, Perugia, and Viterbo. The four prototypes and the experimental set up are described and the potential benefits of this innovative solution are discussed. Preliminary analyses, from December 2020 to December 2021, enable to estimate runoff reduction and thermal properties of multilayer blue-green roofs, underlying the high potential of this nature-based solution, which allows to retain most of the rainfall events and to mitigate the daily temperature variability. HIGHLIGHTS Description of multilayer blue-green roofs installed in four Italian cities.; Analysis of the multilayer blue-green roof retention capacity.; Analysis of the multilayer blue-green roof thermal insultation properties.;

Green roofs (GR) have gained widespread popularity in cities due to their multiple benefits. This review synthesizes the latest knowledge around GR ageing and the associated changes in nutrient runoff quality from GRs. Most GR studies have focused on water quality trends for the first 10 years. Information about nutrient levels in runoff, vegetation, and substrate for older GRs (>10 years) is extremely limited and based on monitoring at snapshot points in time, rather than continuously over time, mainly for GRs in Europe, UK and the USA. Nitrogen (N) and phosphorus (P) levels in GR runoff are initially high, especially in the first-year post-installation (NO3: 0.08-100 mg/L, PO4: 0.01-13 mg/L) and subsequently decline to lower concentrations over time (NO3: 0.05-7 mg/L, PO4: 0.01-1.2 mg/L for GRs over 10 years old). Green roof substrate received most research attention but there is growing interest in how vegetation and microbiome characteristics change with time. The review provides a conceptual model of GR ageing that includes the impacts of seasonal changes and other disturbances (e.g., fertilizer applications, extreme events) on nutrient runoff quality. Recommendations for GR design and management are also provided. Future areas of research should focus on long-term holistic monitoring of all GR components across more climate zones, especially arid and tropical climate zones. Studies comparing GRs of different ages are encouraged. Ageing experiments conducted under controlled laboratory conditions complement field monitoring studies and provide a continuous timeline of changes in GR components and runoff quality as they age.

Across the world, cities and densely populated areas are striving to both uplift the quality of the environment as well as enhance their sustainability. Part of this endeavour entails the promotion of urban greening. In Durban, on the east coast of South Africa, rooftop greening practices are gaining some traction with a view to achieving the sustainable development of a greener environment for the city and surrounding areas, although on a smaller scale than many other cities. There has been little empirical research done on green roofs within a local context, especially concerning green roofs as green infrastructure in urban planning tools for creating sustainable resilient city spaces by helping them mitigate against climate change. The quantitative analysis of this research measured temperatures and the urban heat island effect (UHI) of green roofs, as well as control sites over a seven-year period. The total average temperature differences over a seven-year period during the summer months (January/February) witnessed one green roof measuring 9.2 degrees Celsius lower than the control roof. The rationale for this research was to offer support for the benefits of green roofs in mitigating against an increase in inner-city heat islands in the case of Durban’s Central Business District (CBD).

There is an excellent need for supply-side threats due to the enhanced degradation and reclamation of existing water bodies in the present scenario. This led to the global water crisis. One of the easiest ways to fulfil the growing need for freshwater is the recycling of wastewater. Greywater is a form of wastewater from households, industries, etc., with some less toxic materials. The recycling of this greywater has provoked the development of new and sustainable technologies to meet the growing water demand. Engineered constructed wetlands are considered one of the most economically practical processes to treat greywater due to its minimal footprint. In this case study, we summarize several categories of constructed wetlands, operating conditions, and the effects of biological, physical, and chemical aspects of greywater on their treatment performance. On the other hand, the effluent quality from diverse wetlands is also summarized. Furthermore, it would be better to consider that constructed wetlands’ integrated performance with disinfection may improve the effluent quality to desirable standards. HIGHLIGHTS Constructed wetlands' integrated practices with disinfection improve the effluent quality.; To fulfill the need for freshwater recycling of greywater is necessary.; Engineered constructed wetlands are economically practical to treat greywater.;

This study examines design solutions in construction aimed at creating ecosystems within urban environments. The focus of the study are”green” roofs as a part of “green” building practices (next – green). The problem lies in the lack of a certification methodology for green roofs. The challenge of designing and constructing green building elements is associated with the absence of a certification system for such structures. The aim of this work is to develop a certification methodology for green roofs, which will facilitate the active implementation of such structures in construction and positively impact the ecology of Russian cities. The study covers the analysis of green roofs design and construction, developmentof the stages for green roofs installation, formulating the nomenclature basis of quality indicators for roofing materials, shaping the requirements of normative-technical documentation for conformity assessment, and development of certification schemes for green roofs. The practical result of this work is the development of a certification methodology for green roofs. The methodology can standardize the procedure for conformity assessment to normative values and ensure the objectivity of quality control for green roofs during the design and construction process.

This article explores general concepts related to the diffusion of innovations theory (DoI) and its use regarding the adoption of nature-based solutions, specifically green roofs, in urban areas by private house/property owners in the city of Eindhoven (Netherlands). Given the gap in knowledge on the potential for the adoption of green roofs by private house/property owners as well as barriers and enablers to their implementation from the DoI perspective, we used a model for predicting the adoption of innovations (ADOPT). Results show that the predicted peak adoption level is 3% and that the time to peak adoption level is 17 years. However, the level of adoption can be significantly enhanced by increasing profit benefit (i.e., cost savings) in the years that they are used (+19 percent points adoption), reducing risk exposure (+17 percent points adoption), and improving ease and convenience (+15 percent points adoption), while the time to peak adoption level can be reduced by enhancing relevant and existing skills and knowledge (−3 years), simplifying trialability and innovation complexity (−2 years), and increasing observability (−1 year). Hence, key factors affecting the adoption of green roofs by private house/property owners have been identified, contributing to the formulation of urban climate change adoption strategies.

Green infrastructure on rooftops in urban areas can enhance important ecosystem services. In addition to mitigating water runoff and regulating building temperatures, green roofs can provide food and nesting resources for wildlife. Rooftop gardens can also be utilized to cultivate food crops, giving them the potential to attenuate instances of food insecurity which are commonplace in many urban areas. Given that many crops depend on bee pollination, it is imperative to characterize the rooftop bee community. Therefore, we sampled three urban food roofs near downtown St. Louis, MO during the 2017 and 2018 growing seasons. We found 38 bee species utilizing the rooftop farms. We then compared the rooftop bee communities to those of two nearby ground-level community gardens. The roofs had lower abundances of Bombus species than the ground-level sites while non-native cavity nesters in the genus Megachile were overrepresented. These results indicate that the rooftop bee communities represent a nested subset of the species found at ground level. This has important implications for the management of green roofs for growing crops, as this shift in bee community structure may play a role in determining which crops can be adequately supported with pollination services.

Abstract Background The world's growing population and growing need for food have increased attention to urban agriculture around the world. Most crops grown in urban environments need bees for pollination. However, little is known about bee populations in urban areas and little attention has been paid to the function of these pollinators in cities. Therefore, studying the ecology of pollinating bees in urban gardens and green roofs contributes greatly to urban agriculture. In this study, the results of 87 articles related to the presence of bees in gardens and urban farms were summarized in three general sections. The first part deals with issues, such as the diversity of bees in urban gardens, dominant species in these areas, their nesting type, origin, specialty, and sociality. The second part examines the attractiveness of host plants in urban gardens and farms and their origin for bees. The third section examines the effects of landscape and local variables effects on the presence of bees in urban farms and gardens. Results Our data showed that urban environments, especially urban gardens, contain a high diversity of bees, which honeybees and bumblebees are the most dominant species in these environments. The results of the second part showed that native plants were more attractive to bees than non-native plants. In the third section, most studies have shown the negative role of urbanization on the presence of bees. On the other hand, many studies have shown that the presence of green spaces or other farms and gardens around the studied gardens have a positive effect on the presence of pollinators. Conclusion Urban environments have a high diversity of plants and bees that provides a good opportunity to increase agricultural production in these environments. Planting native plants and creating artificial nests for solitary bees and bumblebees can help attract more bees to urban environments. Converting lawns into floral resources or carrying out agricultural activities around green spaces can also effectively help to increase agricultural production in the city.

Green roofs are used worldwide to mitigate the impacts of extensive urbanization, bringing benefits on social, economic, and environmental levels. In order to promote and facilitate the construction of green roofs by private investors, many countries have developed specific legislative requirements and incentives. However, there still are countries where the construction of green roofs is not properly addressed in the legislation, and where no incentive mechanisms are developed. The good practices in three European countries, leaders in regards to the implementation of green roofs – the Netherlands, Belgium, and Germany, are analyzed in this article. A variety of incentives is introduced to accelerate the construction of green roofs. Different requirements are also set to ensure that the roofs will be designed and maintained to provide the desired benefits. The existing local regulations in Bulgaria and North Macedonia were analyzed as well. The only incentive in Bulgaria is the possibility of reducing the legally required green area by compensating it with a green roof. In North Macedonia, no legislative documents or incentives related to green roofs were found.The regulations, applied in the Netherlands, Belgium, Germany, and other countries can be used as good practice examples, modified, and applied from the authorities of countries that still have not developed their own, in order to motivate the investors and facilitate the construction of green roofs.

Relevance. Modern urbanization processes in Kharkiv are accompanied by an increase in anthropogenic pressure on the natural component, compaction of buildings and reduction of green areas. The concept of green infrastructure is used in many countries around the world; it is the best way to reorganize urban space into modern cities. The purpose of the article is a determination of quality changes of water runoff after passing through of green roofs in Kharkiv, Ukraine. Material and methods. A green roof is the roof of a build, partially or completely covered with vegetation and soil layer. Green roofs are divided into “intensive” and “extensive” types. In the research was studied the frequency of use of green roofs in construction and landscaping on the example of Kharkiv, was conducted an inventory of green roofs in Kharkiv. As the number of green roofs in Kharkiv is rather small, is optimal to choice the particular test sites for research. For chemical analysis, were taken samples of snow, surface runoff from the flat, and sloping green roofs and roof without greening for the content of pollutants. Chemical analysis of the samples was performed by the Laboratory of Analytical Ecological Research of V.N. Karazin Kharkiv National University. The laboratory has the attestation and certificate of ISO 10012:2005 № 01-0155/2019. The study determined the following indicators: pH, nitrites, nitrates, transparency, smell, turbidity, chlorides, general rigidity, total alkalinity, ammonia, zinc, copper, manganese, cadmium, total iron, chromium. Two types often represent green roofs in Kharkiv: parking roofs and cellars. Points of samples are located at Shevchenkivsky and Kholodnohirsky districts. Results and discussion. Results of a study of snow and runoff sampling after a green roof and a roof without landscaping show that most water quality indicators improve after water passes through green areas. Thus, at points the pH, general rigidity, alkalinity, concentration of chlorides, chromium are decrease. The green roof of the first point (parking) also reduces the concentration of nitrites, ammonia, zinc and manganese. The concentration of iron also decreases in the second point. However, there is an increase in the concentration of heavy metals in the water due to their accumulation in the substrate of the green roof. The results of the study are can be used by the Post-Soviet countries, as previously the impact of surface runoff was considered only in terms of the flow of pollutants from storm sewers to water bodies. Conclusion. The results of the study indicate that green roofs contribute to the treatment of runoff, natural replenishment of surface water bodies and groundwater and reduce the load on municipal wastewater treatment plant.

Green roofs are recognised as contributing towards building-related energy efficiency. Since roofs account for 20–25% of all urban surface areas, it is not surprising that such a green system can offer a sustainable solution to decreased energy consumption. The current literature on green roofs mostly focuses on the eco-benefits of such structures. A handful of research papers1 have theorised that as green roofs become more prevalent, there will be associated social outcomes for an urban community. However, empirical work in this space is minimal. This research addresses this gap and contributes to the literature by providing insights into city dwellers’ social experiences when using a green roof space. This study identified a green roof space in central Sydney, Australia: the Alumni Green at the University of Technology Sydney. The roof, containing a garden, a concrete open space and a raised grass area amounting to 1,200 m2, is above parts of the university’s library and classrooms, and is easily accessible by staff, students, and members of the public. Two members of the research team conducted surveys on site. Some green-roof users were also contacted via email. Over 128 individuals began the survey, although after removing responses that were incomplete or containing errors, 104 responses remained. The findings revealed that users, most commonly, relaxed or socialised on the green roof, with exercise a far less frequent activity. Further, those who frequented the green roof once a week or more reported significantly greater social well-being and attachment to place than those who visited less. Likewise, those who visited the green roof for periods of 30 min or more also reported greater social wellbeing. There were no significant differences between frequency and length of use and users’ perspectives on the green roof’s economic, physical, collective identity or environmental impacts. These present findings have implications for urban and landscape designers, as they reveal that green roofs have similar social and place-attachment benefits to those observed of green spaces in the literature. Given that green roofs can fit in places that parks or other open spaces often cannot, their implementation should be encouraged to promote social well-being and place attachment.

The implementation of green roofs in buildings offers various environmental, social, and economic advantages. Despite Malaysia’s rapid urbanization, green roofs are not commonly integrated into existing or new buildings, which limits their potential benefits. Identifying the reasons behind this lack of implementation is crucial to promoting the widespread implementation of green roofs. Although previous works have explored barriers in developed urban areas, little attention has been given to Malaysia, where green roof implementation is still in its early stages. To address this research gap, our study aims to investigate the key barriers to implementing green roofs in buildings in Malaysia. Additionally, the study aims to assess the feasibility and level of support for green roof implementation in Malaysia. We utilized a combination of literature review, questionnaire surveys, and structured face-to-face interviews. Through the utilization of both normalization and the Relative Importance Index (RII) analysis, the findings highlight the presence of three primary barriers that impede the effective implementation of green roofs in Malaysia. Notably, the key barriers are: high/additional construction costs, high/increased maintenance costs, and lack of owner/client interest. Understanding and prioritizing these root causes can empower building owners, developers, and policymakers to develop effective strategies for green roof implementation. Our findings offer valuable insights for promoting sustainable development in Malaysian buildings and contribute to the advancement of green roof practices in the country.

The main aim of this study is to model the Nature-based solution of Green Roofs (GRs) in order to assess their efficiency as a mitigation strategy for UHI effects and extreme summertime temperatures over Attica in Greece. The area of study is a region that encompasses Athens, the largest Metropolitan area of Greece, and the suburbs. The analysis has been performed with the use of an advanced modeling system that consists of the mesoscale Weather Research and Forecasting model (WRF) and the advanced multilayer urban canopy scheme building energy parameter and building energy model (BEP/BEM). The two modules are fully coupled, forming WRF urban. For a better description of the urban environment and in order to use the full capabilities of the urban canopy scheme, 11 urban classes corresponding to the WUDAPT Local Climate Zones (LCZ) were used instead of the 3 traditional urban classes that the default version uses. Sensitivity tests for a major heatwave that affected the area of study have been performed in order to evaluate the impact of GRs on the UHI structure. Results indicate that the modification of the roof energy budget decreased the maximum temperature during heatwaves and altered the spatio-temporal pattern of the effect.

Public transport shelters provide an unused surface that can be utilized in various ways, including for unconventional landscaping. The benefits from greening of public transport shelters are insufficiently studied and unutilized. The article evaluates some of the benefits which may result from the construction of green public transport shelters in the central part of Sofia.There are a total of 2780 aboveground public transport stops in Sofia. In the surveyed area are located 257 stops, 150 of which currently have shelters. The potential of greened shelters to remove PM10 and CO2 from the ambient air is estimated for several different scenarios. If 250 public transport shelters are entirely greened (roof and 3 walls) with Festuca sp., the removed PM10 will be about 20 kg/yr, or 0.01% of the yearly emissions of PM10 from transport in the surveyed area. The sequestered CO2 will be 17047.3 kg /yr., or approximately the CO2 emitted by 40 diesel cars with an average daily mileage of 10 km per day for a year. The reduction of PM10 and CO2 is not significant, however, in a big city with intensive construction and a constantly increasing population, every possibility for greening needs to be explored. Green stops may be used in combination with other measures. Proper selection of plant species and design solutions maximizing the green surface will increase the benefits.

Habitat loss and fragmentation are primary threats to biodiversity in urban areas. Least-cost path analyses are commonly used in ecology to identify and protect wildlife corridors and stepping-stone habitats that minimise the difficulty and risk for species dispersing across human-modified landscapes. However, they are rarely considered or used in the design of urban green infrastructure networks, particularly those that include building-integrated vegetation, such as green walls and green roofs. This study uses Linkage Mapper, an ArcGIS toolbox, to identify the least-cost paths for four native keystone birds (kererū, tūī, korimako, and hihi) in Wellington, New Zealand, to design a network of green roof corridors that ease native bird dispersal. The results identified 27 least-cost paths across the central city that connect existing native forest habitats. Creating 0.7 km2 of green roof corridors along these least-cost paths reduced cost-weighted distances by 8.5–9.3% for the kererū, tūī, and korimako, but there was only a 4.3% reduction for the hihi (a small forest bird). In urban areas with little ground-level space for green infrastructure, this study demonstrates how least-cost path analyses can inform the design of building-integrated vegetation networks and quantify their impacts on corridor quality for target species in cities.

This paper presents a numerical assessment of the influence of green roofs applied in the urbanized catchment on the rainwater outflow hygrogram as well as costs and economic efficiency analysis of the proposed green architecture application. The campus basin of the Lublin University of Technology, Poland, was selected as the object of the study. Three variants of extensive green roof applications were designed. The numerical model of surface runoff was developed in US EPA’s SWMM 5.2 software. The simulations were performed for three different rainfall events of various intensities and durations. The cost efficiency of the proposed green architecture was assessed by the Dynamic Generation Costs indicator, while economic effectiveness was tested by Benefits–Costs Ratio and Payback Period determined for all assumed variants. The determination of economic efficiency indicators was based on investment and maintenance costs estimation, assumed discount rate, and time duration of assessment. Results of numerical calculations showed up to 16.81% of peak flow and 25.20% of runoff volume reduction possibly due to the green roof application. All proposed variants of green roof applications in the studied urbanized catchment were assessed as generally profitable due to possible financial benefits related to heating and cooling energy savings and avoiding periodical change of bitumen roof cover.

The local rise in urban temperature is increasingly exacerbated due to the combined effect of urban heat islands and global climate change. Numerous studies have shown that green roofs (GRs) have great potential for facilitating urban heat mitigation. However, little is known about whether such cooling effects can be achieved under extreme heat conditions. With the expected occurrence of more extreme heat events under climate change, such understanding is crucially important for the effective design of heat mitigation. This study aims to fill this gap by investigating the pedestrian-level cooling effect of GR under two weather conditions (i.e., typical summer weather conditions and extreme heat conditions). This research employed a three-dimensional simulation model, ENVI-met, to simulate pedestrian-level air temperature for three typical residential areas with different roof heights in Beijing. We conducted the simulations in two different roof scenarios, conventional roofs versus green roofs. The results showed that green roofs could provide large cooling exceeding 0.2°C on downwind sides and in the daytime, although the average cooling intensity was small. The pedestrian-level cooling intensity of GR decreased significantly under extreme heat conditions compared to typical summer weather conditions. It varied diurnally following an inverted W-shape for both weather conditions. Results also showed that the pedestrian-level cooling intensity of GR decreased with the increase in roof height in a nonlinear way and became 0 when roof height reached ∼50 m for both weather conditions. The results of our research can provide important insights for cooling-oriented urban design in the future, as we are expecting such extreme weather conditions nowadays may be the new normal in the future.

Spontaneous and ruderal plants can be the key to a low-cost, low-maintenance urban Green Infrastructure that can adapt to the local climate context. In addition to providing a wide range of Ecosystem Services, such species can survive in environments altered by humans and withstand conditions adverse to them, such as water scarcity and shallow substrate. The paper aims to systematically identify the effects exerted by substrate depth during the first months of vegetation growth using the Point-Intercept method in low-maintenance extensive green roofs. Contrary to previous research focusing on vegetation growth in temperate climates, experimentation in a humid subtropical climate can help to fill a gap by assessing the long-term potential of roofs with heterogeneous spontaneous species establishment to improve urban ecology and its natural regeneration.

Long-distance pollen dispersal is critical for gene flow in plant populations, yet pollen dispersal patterns in urban habitats such as green roofs have not been extensively studied. Pollen dispersal patterns typically are assessed either by fitting non-linear models to the relationship between the degree of pollen dispersal and distance to the pollen source (i.e., curve fitting), or by fitting probability density functions (PDFs) to pollen dispersal probability histograms (i.e., PDF fitting). Studies using curve fitting typically report exponential decay patterns in pollen dispersal. However, PDF fitting typically produces more fat-tailed distributions, suggesting the exponential decay may not be the best fitting model. Because the two approaches may yield conflicting results, we used both approaches to examine pollen dispersal patterns in the wind-pollinated Amaranthus tuberculatus and the insect-pollinated Solanum lycopersicum at two green roof and two ground-level sites in the New York (NY, United States) metropolitan area. For the curve fitting analyses, the exponential decay and inverse power curves provided good fits to pollen dispersal patterns across both green roof and ground-level sites for both species. Similar patterns were observed with the PDF fitting analyses, where the exponential or inverse Gaussian were the top PDF at most sites for both species. While the curve fitting results are consistent with other studies, the results differ from most studies using PDF fitting, where long-distance pollen dispersal is more common than we observed. These results highlight the need for further research to compare curve and PDF fitting for predicting pollen dispersal patterns. And, critically, while long-distance pollen dispersal may be an important component of overall pollen dispersal for A. tuberculatus and S. lycopersicum in both urban green roof and ground-level sites, our results suggest it potentially may occur to a lesser extent compared with plants in less-urban areas.

Purpose: As sustainability is quickly becoming a predominant concept at the heart of the 21st century living and thinking, as well as planning for the near future, it has become obvious that financial viability is one of its core determinants. The aim of this paper has been to study the prospects of greater implementation of green infrastructure (GI) and especially green roofs (GR) in Croatia. Methodology: Theoretical framework is based on the relevant literature review, which has been conducted using qualitative methods of analysis, synthesis, comparison, induction and deduction. The empirical part of the study has been conducted as a survey amongst the civil engineering students, using questionnaire as the survey instrument. Results: The theoretical part of the research identified the relevance of costs in GI implementation and its social and economic effects, circularity principles and EU funding options. Empirical findings indicate that the majority of Millennials from the sample find the implementation of GI to be financially demanding. Moreover, they are largely unaware of the availability of EU funding for such purpose and find the frugality aspect of green roof implementation very important. Conclusion: It is acknowledged that financial viability is inevitable when considering the implementation of GI. The level of environmental awareness among Croatian Millennials is satisfactory. However, considering they were not sufficiently aware of the EU funding available for this purpose, there is a need to raise awareness among this population segment, as they are future decision-makers.

The aim of the article is to alert to the fact that architecture must comprehend Nature and bring it back again to the daily life of Man, increasing his physical and psychological comfort. The "Green" in Architectural Rehabilitation can have several meanings and approximations. In this article we address "Green" as Color and Attitude. This paper has been developed through deepening the hypothesis of the color green in living coatings. The creation of an ecological skin in architecture accentuates the dilution of the presence of interventions in heritage contexts with an attitude of knowing how to add, involving Nature. These allow creating solutions that avoid the formalisms of architectural language, being of special relevance their application in the Architectural Rehabilitation of the Heritage. Examples of green roofs and green facades are presented and it is shown that rainwater management improves the sustainability of the historic place. Complementary, as a Green Attitude, it is essential to use renewable energy in buildings to achieve NZEB – Nearly Zero Energy Building. As a case study we have selected the Rehabilitation of the Cathedral of Portalegre in Portugal. Doi: 10.28991/HIJ-2020-01-04-04 Full Text: PDF

There are 265 municipalities in Bulgaria. According to the national legislation, each Municipal Coun-cil adopts an Ordinance for the construction and protection of the green system. Most of the mu-nicipalities have such ordinances, however, only 75 of them stipulate regulative requirements, under which a green roof can be considered a green area. These requirements refer to the substrate depth and are unreasonably high. While positive impacts are reported in green roofs with a substrate layer thickness of 4 – 5 cm, green roofs with substrate depth under 10 cm are not considered a green area in any of the reviewed ordinances. One municipality considers green roofs with substrate 10-30 cm as a green area, under specific conditions. This paper provides a review of the stipulations of the Bulgarian local legislation against the existing data for the effects of green roofs with different substrate depths and outlines the need for amendment of the legislation and future research.

In Bulgaria, public relations associated with spatial planning, investment design and construction are regu-lated by the Spatial Development Act (2001). According to article 62 (10) of this act, each Municipal Coun-cil adopts an Ordinance for the construction and protection of the green system on the territory of the municipality. There are 265 municipalities in Bulgaria and they are free to customise this ordinance as long as the goals and framework of the Spatial Development Act (2001) are maintained. The aim of this article is to review all Ordinances for the construction and protection of the green system available in Bulgaria and to analyse the included information and regulations regarding the construction of green roofs and green walls. The review of the ordinances showed that the construction of green roofs and green walls is not suf-ficiently addressed in the Bulgarian legislation at the municipal level. About 30.2% of the municipalities in the country do not have an Ordinance for development, maintenance and protection of the green system, 33.6% of the municipalities have such an ordinance but it does not mention green roofs and green walls and only 30.9% have an ordinance and it regulates the construction of green roofs and/or green walls.

El desarrollo sostenible requiere la consideración de toda una serie de elementos interconectados, como la reducción de la demanda de energía y el consumo de agua, la minimización de los residuos y la contaminación y la provisión de un transporte público eficiente. Bajo ese enfoque de “construcción sostenible”, el cierre de los ciclos de materiales y agua, así como la reducción del consumo energético son los principales objetivos en el sector de la edificación. En este contexto, el concepto de Infraestructura Verde Urbana (UGI) se ha definido como un conjunto de sistemas de construcción creados por el hombre, pero basados en la naturaleza, como techos verdes y sistemas de ecologización vertical. UGI proporciona varios eco-servicios al entorno urbano, como la reducción de la escorrentía superficial en las grandes ciudades, la reducción del efecto isla de calor, el apoyo a la biodiversidad, la mejora de la durabilidad de las membranas impermeabilizantes y el ahorro de energía en los edificios, entre otros. Durante la última década se han llevado a cabo una serie de acciones de investigación en la Universidad de Lleida con el fin de estudiar estos sistemas constructivos, cuantificar sus beneficios y mejorar su diseño. En este trabajo presentamos estos estudios Abstract Sustainable development requires the consideration of a whole host of interconnected elements, such as the reduction of energy demand and water consumption, minimizing waste and pollution, and providing efficient public transport. Under that “sustainable construction” approach, the closing of materials and water cycles as well as the reduction of energy consumption are the main objectives in the building sector. In this context, the concept of Urban Green Infrastructure (UGI) has been defined as a set of man-made, but nature-based, construction systems, such as green roofs and vertical greening systems. UGI provides several eco-services into the urban environment, such as the reduction of surface runoff in large cities, reduction of heat island effect, support to biodiversity, waterproofing membranes durability improvement, and building energy savings, among others. During the last decade a series of research actions have been carried out at the University of Lleida in order to study these construction systems, to quantify their benefits, and to improve their design. In this work we present these studies

Green infrastructure has received increasing attention in urban strategies in a sustainable and resilience context, since greenspaces provide diverse ecosystem services. Green roofs can be a form of compensating the loss of ecosystem services and biodiversity in urban areas, contribute to safe access to greenspaces, which is important in times of social isolation, due to viral pandemics, and can guarantee self-reliance food. Thus, this urban measure should be integrated in urban planning and management, by using urban indicators associated with citizens access to greenspaces. Hence, we study pedestrian accessibility to green areas and propose an urban solution to improve access to greenspaces. The assessment is developed using indicators related to the citizens living in the surroundings of green areas and the residential buildings that exist in these areas; the residents living in potential green buildings or blocks with private green roofs and the potential green buildings with private green roofs. The ideal standard distances were considered to analyze the proximity of green areas to the dwellings of residents. We used GIS for the assessment of distances over the pedestrian network. The results indicate the necessity of building green roofs through the private sector. The developed indicators provide an important contribution to the municipal management in the definition of criteria for the urban location of green roofs to promote better access to ecosystem services.

Roofs are an integral part of buildings that shape the urban landscape. So much so that every day several hundred square meters are allocated for construction. This impacts already shrinking green areas, which could further lead to a deterioration of air quality, micro-climate, and overall biodiversity. In order to maintain a sustainable area of biologically active surfaces, it is essential to find new ways of introducing greenery into cities. One way is through preserving ecological immutability and reclaiming the built-in rooftop spaces that allow the creation of green roofs and façades on existing and newly designed buildings. Not only does it affect the building's environmental impact, but it also allows the use of such surface area in a multifunctional way. Designers faced with high prices of the land property market are seeking ecological and economical solutions. This innovative way allows direct contact with the natural environment within the urban community. The aim of the work is to present the problems related to roof tiles as a modern and ecological means. The paper contains a review of the literature and presents in a tabular format interesting items related to this issue.

Global wildlife populations are in decline, in part, due to urbanization. However, in urban landscapes, green infrastructure such as green roofs are being created to provide habitat for wildlife. Green roof isolation, planting heterogeneity, and size can all influence wildlife biodiversity, as may the age of a green roof. When new habitat is created, wildlife use of these new habitats is expected to increase over time. To test this expectation for birds, we monitored bird activity prior to and after installation of small green roof plots on six buildings located within New York City parks. Contrary to expectations, bird activity and bird species richness did not increase after green roof plot installation, nor did they increase over a period of 4 years following installation. These unexpected results may reflect the relatively small size of the plots or the fact that the plots were on buildings located within urban parks. Bird activity and bird species richness varied widely between roofs, and the composition of rooftop bird species may have been more influenced by the characteristics of the surrounding landscapes than the presence of the green roof plots. These findings suggest that small urban green roofs within a larger and, potentially, higher quality habitat may not provide additional habitat for foraging birds. Urban green roofs have numerous ecological and environmental benefits, but the size and characteristics of landscapes surrounding a green roof need to be considered when installing green roofs as wildlife habitat.

Agrivoltaics (APV), the co-location of agriculture and photovoltaics (PV), addresses an inherent competition for land usage. Taking the same dual-use concept to the urban landscape, rooftop APV can provide locally grown food in areas of need while providing distributed energy generation. In this multi-year investigation, different APV plots in northern Colorado, USA, were studied for crop metrics, light transmission, air temperature, soil/substrate temperature and moisture. Crops were grown under different solar panel types including opaque silicon and opaque and semi-transparent (ST) thin-film CdTe technologies. Growth conditions were characterized showing generally improved conditions and moderated temperatures under the panels. The ST-CdTe panels had increased photosynthetically active radiation (PAR) compared to both opaque panel types without a significant corresponding increase in temperature.

In view of the demographic revolution and the rapid development of urban environments, the installation of green roofs could be a tool to ensure human well-being (e.g. heat island reduction, rainwater management), or to increase urban biodiversity. However, the relationships between biodiversity and green roofs are not yet clear and little research has looked into this. We therefore reviewed studies on the overall biodiversity of green roofs. Our review has shown that there is a lack of knowledge of the biodiversity of green roofs, with recent consideration. We highlighted the importance of green roof contribution, in maintaining urban biodiversity through three lines of research: characterization, modes of use and design. Furthermore, we found that there were very few studies on soil biodiversity on this topic. We concluded that green roof construction guidelines should integrate soil communities into their design and aim to be heterogeneous at roof and landscape level. Future research should focus on the diversification and redundancy of rooftop conditions in the urban matrix. This would increase the area of green habitats and the success of species dispersal in cities.

Urbanization has promoted economic growth but it can increase gust wind speed, which may lead to serious damage to infrastructures. This study uses the Weather Research and Forecasting model and a gust parametrization scheme to evaluate the mitigation impact of white roofs and green roofs on wind gust over the Pearl River Delta, an urban agglomeration in Southern China in June, July, and August of 2014. The results show that both white and green roofs decrease the gust wind speed by decreasing the mean wind speed, suppressing the turbulent motion and weakening the convection. The impacts of white roofs are stronger than those of green roofs. The daily mean reductions of gust wind speed are approximately 1.2–1.3 m s ^−1 (12%–16%) and 0.4–0.6 m s ^−1 (6%–10%) by white and green roofs, respectively. In general, the contribution of turbulence (60%–85%) to the gust wind speed is the largest, and the contribution of mean wind speed is approximately 10%–30%, however, the effect of deep convection is not obvious (0%–15%) on the decrease of gust wind speed. The effect of cooling roofs on reducing the gust wind speed is stronger during daytime than during nighttime, and the effect is more significant in city areas that have higher building densities. Based on the findings, this study is potentially beneficial for policy-makings in developing urban disaster mitigation methods.

Many cities are vulnerable to flooding due to their high proportion of impervious surfaces and lack of vegetated land cover. This vulnerability will often be exacerbated by changing rainfall and storm patterns due to climate change. Using the principles of urban biomimicry, this study aims to show an ecosystem service-based approach to designing an urban green infrastructure network for stormwater management in densely built areas that more closely emulates natural hydrology processes. Nature Braid (next-generation LUCI) is an ecosystem services assessment tool that was used to simulate flood mitigation ecosystem services in a 13.7 km2 urban water catchment in Wellington, Aotearoa New Zealand. The simulation results revealed that 59% of the catchment does not contain or benefit from flood-mitigating land cover features. Adding 0.6 km2 (4% of the catchment) of green roofs alongside major stormwater flow paths resulted in a nearly three-fold decrease (11%) in the unmitigated flooding area. These results suggest that green roofs could help manage stormwater and mitigate flooding in the densely built areas of the catchment. Using ecosystem service assessment tools, like Nature Braid, can inform the design of more regenerative and resilient urban green infrastructure networks that help mitigate climate change impacts on urban residents.