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Mongolia is experiencing unprecedented urbanization along with recent economic growth. Ulaanbaatar is known to be the coldest capital in the world and heating demand is very high during the long winter season. Due to the increase of coal burning to provide heat, there is an urgent need to improve housing and to reduce energy use and air pollution. Currently, there is a revitalization of the Ger area of Mongolia and this presents a good opportunity to redevelop the region into an ecologically designed district with sustainable housing. Such a redesign will result in energy saving and air pollution reduction. With this goal in mind, a pilot project called Create Accord Living Environment (CALE), was developed to demonstrate living conditions with a new house design that is cost effective for Mongolia. This paper presents the house performance using an energy simulation and the results are correlated with measurement data taken during the wintertime. The average energy use intensity (EUI) for 5 CALE houses was found to be 112 kWh/m2/yr. This is a 71% energy savings compared to a typical detached house with a modern and efficient house design. If it is possible to redevelop 1000 houses in the Ger area, an estimated 6.5 kton/yr in carbon emission can be saved. In addition, a parametric study was conducted to investigate the impact of different construction materials, craftsmanship quality, and occupants' behavior on the house's energy efficiency. The proposed housing structures, which provide a comfortable living space with significantly reduced energy utilization, serves as a potential model for development both within Mongolia as well as for other similar climates.

Heating and cooling in high-rise buildings devour about one-third of overall energy consumption. Skycourts is increasingly integrated in high-rise buildings, in particular offices. Skycourts are perceived as transitional and social nodes. This paper aims to investigate potentials of a skycourt when perform as a ventilated buffer zone in offices in a temperate climate. Using a hypothetical office building in London, a coupled approach of energy simulation and CFD was carried out for two ventilation modes; air-conditioned skycourt, and alternative models that incorporate combined ventilation strategies with the adjacent offices’ zones of the skycourt. Furthermore, to determine the most critical ventilation conditions, different parameters were investigated. Overall, the results highlight that the incorporation of a ventilated skycourt potentially has a significant impact on the annual energy consumption. The optimized parameters enhance comfort temperature ranges of skycourts. Finally, the study developed guidelines to define the most effective configurations of ventilated skycourts.

Due to the increasing magnitude and high frequency of urban heatwaves, recently, there has been a surge of interest in the reflective roofs and the vegetative green roofs. Along with the rising temperature, there are also more frequent droughts and rainfall which have led to wider changes in weather conditions subsequently affecting the performance of green roofs and white roofs. However, there is still a lack of research in comparing dynamic energetic and hydrological performance of green roof and white roofs during heatwave events. This paper introduces a newly constructed outdoor test rig (installed with a semi-intensive green roof and an aluminium white roof) and a few initial monitoring results. The hydrological performance monitoring results showed that, although a noticeable peak runoff reduction of the white roof was observed, more significant water retention of green roofs had been established. The energetic performance monitoring results indicated that the green roof performed better than the white roof during the heatwave event reducing solar heat gains by 76% during day time, improving U-value by 28% and reducing indoor air temperature by 2.5°C. The peak indoor air temperature reduction in the green roof space occurred during late afternoons (around 7 pm).

This paper presents the results for the operating energy performance of the smart operation for a low carbon energy region (SOLCER) house. The house design is based on a &lsquo, systems&rsquo, approach, which integrates the building technologies for electrical and thermal energy systems, together with the architectural design. It is based on the concept of &lsquo, energy positive&rsquo, buildings, utilising renewable energy systems which form part of the building envelope construction. The paper describes how the building energy model HTB2, with a range of additional &lsquo, plugins&rsquo, has been used to simulate specific elements of the design and the overall energy performance of the house. Measurement data have been used in combination with the energy simulation results to evaluate the performance of the building together with its systems, and identifying the energy performance of individual components of the building. The study has indicated that an energy-positive performance can be achieved through an integrative systems approach. The analysis has indicated that the house, under normal occupancy, needs to import about 26% of its energy from the grid, but over the year its potential export to import ratio can reach 1.3:1. The paper discusses the performance gap between design and operation. It also considers the contribution of a transpired solar air collector (TSC) to space heating. The results have been used to gain a detailed understanding of energy-positive performance.

During winter-time in Mongolia, the air pollution is so severe that it threatens the citizens’ health. Ulaanbaatar is the capital city of Mongolia, and its population represents about half of the total population of Mongolia. The majority of people in the Ger area, approximately 50% of population of Ulaanbaatar, rely on direct coal burning to generate the required heat to maintain a comfortable environment in the cold season. The heavy reliance on coal leads to catastrophic air pollutant emissions including carbon dioxide, sulphur dioxide, nitrogen oxides and particulate matter, which leads to global warming, climate change and human health. As it is identified that building insulation retrofit is one of the best ways to reduce the reliance on coal consumption due to the improved heat retention and air tightness, a tool, named “FIXIT” has been developed to quickly quantify the impact from insulation retrofit. This paper presents how “FIXIT” was developed and is applied to help house owners to understand their building performance. Not only can “FIXIT” be applied for individual houses, it can also be used to estimate the reduction of air pollution from coal burning due to insulation retrofit. With “FIXIT”, it is estimated that about 530 ktons of carbon emissions reduction can be targeted by applying building insulation retrofit, if around the 100,000 detached houses in Ulaanbaatar apply insulation retrofit. By highlighting the advantages on the building performance, “FIXIT” can encourage more house owners to improve their house insulation quality and thus contribute to the air quality, creating a cleaner and healthier environment and saving on fuel use.

This study investigates public participation in heat impact reduction by analysing adaptive behaviours, familiarity with urban heat island (UHI) and cooling strategies, the perceived urgency of heat impact actions and citizen's willingness to pay through a questionnaire survey in Chongqing, China. The results indicate that air-conditioning systems are the dominant cooling facility in both work and living environments. Respondents had a moderately familiar understanding of several cooling strategies such as urban vegetation, shading devices, water-based artificial facilities, urban design for shading and ventilation and water bodies. Familiarity with innovative materials and techniques for pavements, roofs and facades was less than moderate. Urban planning and design for heat resilient cities was thought to be the most urgent intervention, followed by the establishment of temporary cooling facilities. Most respondents indicated that cost-sharing mechanisms for urban heat prevention and control systems should at least include the government, whilst 50% of the respondents preferred collaborative payment among government, developers, and owners. Only 41.6% of the interviewees expressed their willingness to pay, with a share varying between 80 RMB. A conservative estimate indicated that there could be an average payment of 45.95 RMB and 19.10 RMB among the 234 respondents who were willing to pay and all 562 respondents regardless of willingness, respectively. Respondents’ heat-related responses and actions towards urban heat challenges were dependent on a wide range of factors like gender, age, education, economic status, health, exposure, habit formation and behavior change, social acceptance, etc. Moreover, such factors could interact with each other affecting public behavior with different weights. Overall, this study increases our understanding of people's perceptions and proactiveness in reducing urban heat and provides guidance for decision-makers towards a novel user-aware approach to the implementation of urban heat prevention, adaptation, and mitigation strategies.

A number of innovations in building envelope technologies have been Received 9 August 2016 implemented recently, for example, to improve insulation and air Accepted 24 September 2017 tightness to reduce energy consumption. However, growing concern KEYWORDS over the embodied energy and carbon as well as resource depletion, is Adaptability; energy beginning to impact on the design and implementation of existing and conservation measures; novel building envelope technologies. Biomimicry is proposed as one ecological design; intelligent approach to create buildings which are resilient to a changing climate, building; green building; embedded in wider ecological systems, energy efficient and waste free. biomimicry; biomimetics; However, the diversity of form and function in biological organisms and adaptable facade; plant cell therefore potential applications for biomimicry, requires a holistic wall approach spanning biology, materials science and architecture. It is considered timely to re-examine opportunities to learn from nature, including in the light of recent understanding of how plant form and function are determined at the cellular levels. In this article, we call for a systemic approach for the development of innovative biological and living building envelopes. Plant cell walls are compared to building envelopes. Key features of cell walls with the potential to inform the development of design principles of biological and living building envelopes are identified and discussed.

With around 1-2% annual replacement of the UK’s housing stock, housing retrofit must play a major role in reducing future energy use and CO2 emissions. This paper presents a whole-house approach for energy retrofit for five houses located in South Wales. This ‘systems based’ approach combines reduced energy demand, renewable energy supply and battery storage. The paper describes a combination of energy modelling, using the building energy model HTB2, and field measurements to analyse the performance of the houses before and after retrofit. The results indicate that significant reductions in energy use, CO2 emissions and energy costs can be achieved using a whole house approach, combining energy efficiency with building integrated renewable energy generation and energy storage. CO2 emission reductions are estimated to be in the range of 50-75%, with cost savings of £402 to £621 per year. The cost of carrying out the retrofitting ranges from £23,852 to £30,510. Although retrofits are still relatively expensive in relation to their annual cost savings, there are multiple benefits relating to reducing fuel poverty, reducing electricity grid stress and contributing to national CO2 emission reduction targets. Also, as costs of measures are further reduced and energy prices likely to rise in future, the cost balance will change more in favour of whole house retrofit. The paper demonstrates the advantages in using a combination of energy simulation and field monitoring to investigate the performance of buildings in use, which in this case concerns the impact of carrying out energy retrofits in housing.

Due to global warming and energy exhaustion, building retrofitting has attracted increasing attention worldwide. With 67.1 billion square meters of existing building area, China normally targets separate defect remedies to improve building energy efficiency in conventional renovation practices rather than taking a holistic approach to optimize whole building performance.\ud \ud This article presents a working procedure that is employed in the decision-making process of domestic retrofits in China from an architect’s perspective, combining building-sculpt redesign with the overall performance targets. This study examines three representative residences of different ages and dimensions as case studies to demonstrate a simulation-based holistic approach of integrating form, fabric and system strategies to improve environmental performance and reduce house-hold energy consumption without compromising building aesthetics in retrofit design. Different retrofit routes and corresponding priorities should be applied towards different conditions for different purposes. The simulation results indicate that within the service life, the older the residence, the greater the retrofit potential. For the 1981 residence, a holistic approach could achieve an energy savings of 78.1% and a CO2 savings of 92.6%. For the 1995 case, the holistic approach could reduce energy consumption by 66.6% and CO2 emissions by 76.6%. When designed properly, a 36.9% reduction in energy consumption and a 44.6% reduction in CO2 emissions could be achieved for the 2002 residence.

An on-site renewable energy system is developed and presented in this paper to supply electricity usage of potato cold stores in a UK food park. The system is designed to use the mass of the potatoes to store surplus power from PV when there are days of high solar radiation. It can also be charged from the grid during off-peak time when there are longer periods of overcast conditions. The paper presents results to show energy generated by the PV that can be used in the cooling system, and the storage potential of the potatoes in offsetting grid supply. The dynamic thermal model HTB2 with an energy system extension is employed to design the energy system. The base case representing the existing scenario is validated with previous weekly metering data. The system performance is examined in terms of annual energy performance and long-term cost-effectiveness. The simulation results indicate, 1) the cold store with potato storage is able to maintain the required temperature ranges for most periods when cooling is only powered by electricity from PV during peak-time, and it contributes to energy cost savings and electricity import reduction, but almost no cooling reduction; 2) the system combination of solar PV and off-peak cooling can be paid back within its lifespan, with the most optimal case taking only 11 years. The outcome of the research demonstrates the benefits of the optimized renewable energy system, which provides free or cheap energy supply, reduces industry-related CO2 emission, and contributes to overall energy cost savings. This technique might be applied to other type of food storage, where the thermal mass can contribute to thermal storage.

Transitional spaces have been widely applied in building designs. They may account for 10–40% of total volume in different types of buildings. Maintaining an acceptable level of thermal comfort for transitional spaces poses challenges to building designers and engineers. However, there is not in general a recommended acceptable comfort range for transitional spaces, nor are there specific thermal comfort prediction methods. This paper aims to investigate the thermal environmental performance and people's adaptive comfort in transitional spaces, by conducting field studies, which include on-site questionnaire surveys and physical measurements. Field studies were carried out for three selected case study buildings in Cardiff, each having some forms of transitional space. They were the National Assembly for Wales Senedd, the Hadyn Ellis Building and the Royal Welsh College of Music and Drama. The total responses from the questionnaire surveys were 736 and 580, for all buildings, during the summer period in 2017 and the winter period in 2018 respectively. This paper first presents the findings from the field studies, followed by in-depth analysis of human adaptability to thermal environment. Strong correlations were identified between clothing value and indoor operative temperature. People's adaptability to the thermal environment is confirmed, with nearly 80% of the respondents opting for self-adaptive actions to overcome uncomfortable situations. The identified 90% acceptability comfort band (−0.5 < TSV< +0.5) were 4.0 °C and 4.2 °C for the summer period and the winter period respectively, implying that a fine control of the indoor temperature to maintain an acceptable comfort level is not necessary.

Several studies analyze the thermal performance of vegetated roofs, presenting either mathematical models or experimental quantifications of heat transfer process through them, also showing the effect of vegetation and soil parameters on the thermal and energy performance of this type of roofing system. However, presently the level of availability of these parameters, has not been enough considered. This work intends to investigate this underestimated issue of the green roofs’ thermal modeling, through the consideration of the availability of parameters pertinent to the shortwave radiation exchange, which are adopted by models based on leaf area index (LAI) and on the fractional vegetation coverage (σf). From the analysis of these models, the importance of a precise knowledge of such parameters arises, despite the availability of their values is still limited. In addition, the absence of a proper database including several green roof plant species and information on their stage of growth, to which a technician possibly will refer in the case of lack of field data, represents quite a worthwhile matter because it may lead to inaccurate estimations of the thermal loads for climatization of buildings equipped with green roofs. In this respect, the manuscript reports an estimation of the errors potentially occurring when not specific vegetation data are used. This evaluation is based on simulations, performed with the DesignBuilder© software, showing the energy effects produced by different assumptions in the green parameters (that is by adopting experimental data revealed by authors and a potential mix of the literature available parameters). Thus, the mission of the paper is to enlighten a difficulty that a technician possibly will encounter when performing an energy and thermal simulation of a green roof; therefore a strong call for making the current database more tailored on green roofs has also arisen.

Green residential architecture is reviewed considering the green movement that has taken place since the 1950’s to 2010’s describing and evaluating the most relevant housing projects that integrate an energy systems approach to reduced demand, renewable energy supply and energy storage. This review shows that green residential architecture has evolved significantly, has been named differently depending on the interests or concerns at the time, and has advanced at varying speeds depending on the technological, economic, environmental and political barriers and drivers at the time. Eighty-two green residential case studies are evaluated, focusing on the UK (30% of the case studies), but also Europe, the USA and worldwide. It is found that the most popular strategies for reduced energy demand are fabric first approach (89% of the case studies) and mechanical ventilation with heat recovery (64%) for renewable energy supply are solar thermal collectors (79%) and photovoltaic panels (58%), and for energy storage are hot water tanks (57%). In conclusion, 67% of the case studies have a whole energy systems-based approach with an average of 5.2 technologies per house.

European governments have set ambitious retrofitting targets driven by the commitment to reduce the greenhouse gas emissions by at least 80% by 2050. The United Kingdom has the oldest housing stock in Europe, with over 2/3 of dwellings built before 1976, when building regulations started to include energy efficiency. This raises concerns over carbon emissions, health, comfort and running costs, and government’s set targets and initiatives for significant improvements. Deep retrofitting by using innovative technologies with respect to aesthetics has considerable and measurable benefits, while it can be a costly and challenging process. This study examines a combination of measures undertaken in a pre-1919 dwelling in south Wales, including reduction of energy demand and the application of renewable energy supply and energy storage. A whole house performance and a systems breakdown evaluation is presented comparing the pre and post intervention status. Both monitoring and modelling tools where used, and the performance gap is also discussed. An annual reduction of 34% in space heating and 78% in electricity import was monitored with an additional electricity export of 3217kWh. This represents a total annual cost saving of £1115, at 2019 UK gas and electricity prices. The total cost of the retrofit was £55K.

Since the energy crisis of the mid and late 1970s, society has been aware of the need for a built environment that uses less fossil fuel energy. Although the built environment accounts for a large proportion of global fossil fuel use, it may be argued that the energy and buildings agenda is not being addressed at the depth or scale needed to meet global and national CO2 emission-reduction targets. Most actions to reduce energy use in the built environment have mainly used a ‘top-down’ decision-making approach, from government and industry, with little end-user engagement. Greenhouse gas emission-reduction targets will not be met without providing the technological and socio-economic pathways for achieving them. The paper is divided into three parts. Firstly, it discusses the need to reduce fossil fuel use and the apparent failure to transition policy goals and aims into practice. Secondly, top-down and bottom-up approaches are reviewed, advocating a greater emphasis on a ‘whole-system’ bottom-up approach in delivering multiple benefit solutions. Thirdly, the concept of ‘smart’ is considered in relation to bottom up with its implementation at a regional scale.

To improve energy efficiency of office buildings in Tianjin, we select a prototypical high-rise office tower as an example and focus on the effect of geometric factors on building energy performance. These factors include the orientation, plane shape, floor area, plane shape factor (the ratio of the plane length to the plane width, only as regards to a rectangle-shaped plane), floor height, floor number and window-to-wall ratio. The simulation is performed in DesignBuilder, which integrates artificial lighting with instantaneous daylight during the energy simulation process. The geometric factors of the defined prototype are examined in both single-parameter and multi-parameter evaluations. As to the multi-parameter results, the energy saving rate can vary by up to 18.9%, and reducing the floor height is observed to be the most effective means of reducing annual total end-use energy consumption, followed by increasing the plane shape factor and reducing the floor area. The results can serve as a reference for passive design strategies related to geometric factors in the early design stage.

Rapidly growing energy consumption and associated carbon emissions from building clusters and transport activities have raised concerns. Predicting carbon emissions combing building clusters and transport activities due to buildings’ users is an effective way to getting a better understanding of their energy use and carbon emissions, and thus to control carbon emissions for low carbon development. The purpose of this paper is to quantify and compare operational energy consumption and associated carbon dioxide emissions from building cluster and transport activities due to the buildings’ occupants. The energy consumption and carbon emission features on building cluster and transport activities are then presented and analysed. Finally, relevant low-carbon development strategies in the built environment from building cluster and transport activities are outlined and discussed. The results of the case study have shown that: (1) Energy consumption and carbon emissions from building clusters are almost four times higher than transport carbon emissions due to buildings’ users in the unit of the square metre per year. Therefore, more focus on energy-saving should be emphasised on the buildings sector compared to the transport sector. (2) Different building types significantly varied in energy demands. Specifically, residential buildings have the highest heating demands, while public buildings in term of commercial, office and hotel buildings consumed more energy on cooling demands. (3) Transport-related carbon emissions due to mobility from buildings’ users by car and taxi are the primary sources of carbon emissions. The highest average carbon emissions come from private cars/ taxis. By contrast, public transport has the lowest average transport carbon emissions due to their per capita low carbon emission factor. Transit modes are the preferred low carbon travel modes, so these should be promoted.

This paper presents an evaluation of the economic and technical feasibility of a renewable-led low carbon house in the UK. A holistic systems-based approach to achieve energy positive house has been taken. Long-term economic and technical feasibility analysis have been carried out based on a validated thermal and energy model of the house. The economic analysis employs the Return on Investment (ROI) method and considers changes to government financial support and technology progress over time. Results show that the extra investment on the house, compared with that for building a standard social house of similar size, can be paid back within the system lifespan under both the old Feed-in Tariff and its proposed replacement with reduced financial support. Variants examined in the technical feasibility analysis include housing type, orientation and location. Results show that the house can be replicated to achieve an energy positive performance for all variant combinations. Among the variants, location has the highest impact on building performance including annual electricity import, CO2 emission and electricity self-sufficient ratio, with South UK performing better than North UK. This implies that more efficient or advanced technologies would be needed to achieve similar building or system performance in areas of unfavourable climate. The outcome of the research has demonstrated the affordability of the energy positive house, and the technical feasibility of its replication with different housing types, orientations and locations in the UK. This study supports the wide scale replication of this affordable systems-based approach in domestic building design and construction when incorporating appropriate technologies.

This paper presents the design of a monitoring protocol to support retrofit strategies and drive the evaluation of a low carbon house. Monitoring is used during pre-intervention stage to facilitate the decision-making process, as well as in the post-intervention to evaluate the performance of the building and systems. The first phase refers to monitoring as a diagnostic tool with a view to reduce the uncertainty of suggested low carbon solutions by providing real measurements and evidence on building conditions, comfort, systems and occupants behaviour and interactions. The second phase utilises monitoring as an evaluation tool to quantify benefits and challenges of the retrofitting by providing information and analysis on the supply and demand reduction, the difference in comfort and the effectiveness of each intervention. The study explains the protocol development and discuss different monitoring depths and requirements based on the performance indicators required. A typical pre-1919 Welsh end-terraced dwelling is used as a case study to demonstrate the two phases of the proposed protocol. The protocol was developed as part of the Low Carbon Built Environment (LCBE) project at Cardiff University and it was tested in various building types and research-led retrofit packages.

Over the last twenty years China has witnessed rapid urbanisation process. The modification of urban land surface due to urbanisation changes not only affects the geometry of an urban settlement but also its thermal properties, which may give rise to the urban heat island (UHI) affect. Although there has been a large amount of research on mitigation strategies of UHI at the urban scale, there is still a lack of research that concerns the influence of urban geometrical settlement on UHI at a city block scale. Chengdu, a megacity in south-west China, has been chosen as the research subject in this study, to identify the existence of the UHI phenomenon, to measure its magnitude, and to investigate the relationship between UHI and urban design variables, including Floor Area Ratio, Building Coverage Ratio, Green Coverage Ratio, Building Height, Plot-layout Form, and Project Type (function). In this study, urban maps of UHI had been derived from MODIS satellite data for 103 selected projects and 28 urban zones. Correlations were carried out between UHI intensity and urban design variables. The study has developed design guidelines for improving outdoor thermal performance at an city block level. Moreover, a new approach to observe UHI at multi-scales in a long-time period had been conducted, providing a new method to analysis UHI at a city-block scale.

Fuelled by rapid urbanization, urban spatial expansion is increasingly encroaching on the rural hinterland of large metropolises in developing countries. Peri-urban residential settlement development in Chinese cities has seen unprecedented rate in recent years, however, its current situation and implications for sustainability are little understood. The purpose of this paper is to understand through empirical findings the current situation of peri-urban residential settlement development in a Chinese city and examine their progress against the requirements of the sustainable development agenda. In this paper, three recent development cases located in the city periphery of Tianjin, China are studied and a theme-based evaluation framework is used to examine their outcomes. Their specific approaches to achieving sustainable development are discussed, and emerging problems and challenges are identified and analysed with suggestions for the complementary approaches and progression in the planning and management of peri-urban settlements.

The significance of retrofitting the existing housing stock is considered for the policy commitment of delivering an 80% CO 2 emission reduction by 2050. Background issues of energy, legislation, potential and actual CO 2 savings, socio-economics (payback, fuel poverty, health impacts, employment stimulus, etc.) are discussed. Different potential retrofit strategies for the housing stock are presented. Three large-scale housing retrofit programmes in Wales, UK, are analysed for energy savings (using the Energy and Environmental Prediction Model), CO 2 reduction and costs. Two ‘whole house’ retrofit projects in Wales are also assessed, one of which has been the subject of long-term monitoring. Data are compared on a range of retrofit options: different strategies (elemental, multiple and whole-house measures), costs, actual CO 2 reductions and associated benefits. The findings indicate that as the cost of measures rise in relation to the predicted savings, reasonable paybacks will be difficult to achieve, particularly for finance packages such as the ‘Green Deal’. There are funding opportunities for installing ‘shallow’ elemental measures to reduce CO 2 emissions by 10–30%. However, the large-scale financing of ‘deep’ (60–80% reductions) whole-house packages of measures is not currently available and does not pay back.

There is a global trend to deliver zero carbon buildings,\ud with European countries required to deliver near zero energy housing by 2020. This paper presents the results\ud of the simulation of the energy performance of the SOLCER house. The house was designed using a ‘systems’ approach to integrate the building technologies for thermal and electrical energy systems, based on the concept of buildings as power stations, using the renewable energy systems as part of the building envelope. The aim was to produce a house that achieves an ‘energy positive’ performance, which, on an annual basis, generates more energy than in consumes. The house is designed for wide-scale application, so, in addition to energy performance, the focus was also on affordability and ease of build. In order to assess the performance of the house a model was needed to assess the whole building energy performance of the building and its integrated energy systems. The paper describes the development of a simulation model based around the building thermal model, HTB2 (Heat Transfer in\ud Buildings: version 2). A number of sub-models were constructed to simulate the innovative heating, ventilation and power systems. Results are presented\ud relating to seasonal performance of the building, which\ud demonstrate that on an annual basis the building is around 70% self-sufficient in its energy needs, with a\ud grid export to import rate is 1.75.

Urban planning is a vital process in determining the functionality of future cities. It is predicted that at least two thirds of the world’s citizens will reside in towns and cities by the middle of this century, up from one third in the middle of the previous century. Not only is it essential to provide space for work and dwelling, but also for their well-being. Well-being is inextricably linked with the surrounding environment, and natural landscapes have a potent positive effect. For this reason, the inclusion and management of urban green infrastructure has become a topic of increasing scientific interest. Elements of this infrastructure, including green roofs and facades are of growing importance to operators in each stage of the planning, design and construction process in urban areas. Currently, there is a strong recognition that “green is good”. Despite the positive recognition of urban greenery, and the concerted efforts to include more of it in cities, greater scientific attention is needed to better understand its role in the urban environment. For example, many solutions are cleverly engineered without giving sufficient consideration to the biology of the vegetation that is used. This review contends that whilst “green is good” is a positive mantra to promote the inclusion of urban greenery, there is a significant opportunity to increase the contribution of plant science to the process of urban planning through both green infrastructure, and biomimicry.

This study focuses on the optimum cooling effect of trees with ground materials modification in mitigating the urban heat island (UHI) and the benefits towards building energy performance in tropical climate. The modification focused on both physical properties – i.e. tree canopy density and quantity; and the albedo values of ground materials. Two phases of methodology were developed and applied using field measurement and computer simulation. This study measured the average monthly UHI intensity found to be +2.6 °C. In mitigating its impact, higher levels of tree canopy density (LAI 9.7) coupled with “cool” materials (albedo of 0.8) produced the largest urban air temperature reduction. Simulations predicted an average air temperature reduction of 2.7 °C when compared with the current condition. Further, both modifications were found to produce a potential building cooling load reduction of up to 29%. In fact, the optimum improvement of both outdoor and indoor environment was influenced by three major physical factors, namely, larger tree quantity, higher canopy density and cool materials. Thus, it is suggested that appropriate guidelines, influencing implementation of these improvements could be implemented in order to mitigate the UHI effect in tropical climate.

This study assessed the influences of operative temperature on occupants’ perceptions of indoor thermal condition in three non-air-conditioned multi-storey hostels in Klang Valley, Malaysia. The thermal conditions of 24 measured rooms were recorded with and without an operating ceiling fan from May until July 2007. Measurements were made simultaneously at three different floor levels, namely, at the first, fifth and top floor of each of the case study hostels. A questionnaire survey was completed by 298 female student occupants of the same case study hostels. The results suggested that even though a significance above p < 0.01 was recorded between the operative temperatures with and without fan operation, the temperature difference remained small, i.e., from 0.5 K to 1 K. The findings of the questionnaire survey showed that the occupants perceived the thermal conditions in rooms that were shaded with a projected balcony (shading ratio of 0.9), a long roof overhang (shading ratio of 1.6) and an operable window-to-wall ratio of 0.3 to be thermally comfortable.

Possible solutions for zero energy building design in UK are discussed in this paper. Simulation software (EnergyPlus and TRNSYS 16) are employed in this study, where EnergyPlus simulations are applied to enable facade design studies considering building materials, window sizes and orientations and TRNSYS is used for the investigation of the feasibility of zero energy houses with renewable electricity, solar hot water system and energy efficient heating systems under Cardiff weather conditions. Various design methods are compared and optimal design strategies for typical homes and energy systems are provided.

This study focuses on assessing the effects of the indoor climate in typical multi-storey hostels in Malaysia on student occupants through objective, subjective and evidence based prioritisation measurements. The objective measurements consisted of operative temperature; daylight ratio; luminance and indoor noise level. The subjective measurements were sampled from the student occupants' thermal, visual, acoustics and overall indoor comfort votes. The prioritisation measurement using Multiple Linear Regression and Friedman Tests assessed the relationship between physical indoor thermal, visual and acoustics conditions and students' overall indoor comfort perception vote. Findings suggest that subjective sensor ratings were significantly more reliable than objective measurements at predicting overall indoor comfort. Moreover, students living in hostel rooms with projected balconies voted that they were more satisfied with their indoor condition than the ones living in rooms without projected balconies. The results of this study also provide evidence that student occupants were more concerned with their rooms' thermal condition then followed by acoustics and finally visual conditions.

Conventional tropical building designs are experiencing a new paradigm in their environmental response to improve lighting ambiance and occupants’ visual comfort through the exploitation of daylighting. However, it is important for architects to understand that flaws in daylighting strategies could lead to disadvantages as they could hinder vision, cause discomfort, increase interior heat gain, and result in excessive energy demands. The objective of this study was to assess how occupants’ perceived their visual conditions through daylight ratio and luminance level measurements. Measurements were conducted throughout a 2-month period starting from 12th May to 3rd July 2007. Three case studies were conducted at typical Malaysian hostels located in the Klang Valley. Those selected were: the Twelfth Residential College, Universiti Malaya (H1); the Eleventh Residential College, Universiti Putra Malaysia (H2); and Murni Student Apartments, Universiti Tenaga Nasional (H3). The daylighting source in all these case studies were from side-lit windows. Overall, the findings suggested that occupants were at ease with the level of daylighting available in their rooms even though rooms that were shaded by projecting balconies (i.e.,: H1) were dimmer than the rooms that were not shaded (i.e.,: H2 and H3).

The need to design for low energy consumption dwellings has induced Malaysian architects to design naturally ventilated high-rise hostels (HH), near the capital, Kuala Lumpur. Objective and subjective measurements for thermal comfort investigations were conducted in two high-rise university hostels located in Universiti Malaya, Petaling Jaya (HH1) and Universiti Putra Malaysia, Serdang (HH2) from May 12 to June 19 in 2007. Eighteen rooms located at first, fifth, and top floor of each HH were measured for different orientations. The measured rooms were naturally ventilated with ceiling fans. Thermal comfort variables were measured prior to the subjective measurement. A total of 208 student occupants responded to the questionnaire. Subjects with 6 months and over living experience in those HH were selected randomly. This study was aimed: (1) to assess the indoor microclimate of each naturally ventilated HH, (2) to identify student occupants' thermal sensation during rainy and clear day, and (3) to simulate the neutral operating temperature for rooms in naturally ventilated high-rise hostels. Findings revealed that room in HH1 which is located on high land and shaded has a more constant operating temperature distribution than rooms in HH2 that is located on lower land and un-shaded. Operating temperature ranges for HH1 and HH2 were 27—31°C and 26—41°C, respectively. Results suggested that there is also a possibility that thermal comfort is achievable in shaded naturally ventilated hostels with a window-to-wall ratio of 0.35 where the internal—external relative humidity is above 70% RH, especially in south-facing rooms.

This paper discusses the thermal effect of covering the building envelope with vegetation on the microclimate in the built environment, for various climates and urban canyon geometries. A two-dimensional, prognostic, micro scale model has been used, developed for the purposes of this study. The climatic characteristics of nine cities, three urban canyon geometries, two canyon orientations and two wind directions are examined. The thermal effect of green roofs and green walls on the built environment is examined in both inside the canyon and at roof level. The effects of this temperature decrease on outdoors thermal comfort and energy savings are examined. Conclusions are drawn on whether plants on the building envelope can be used to tackle the heat island effect, depending on all these parameters taken into consideration.

This study explores the interaction between perceived and calculated thermal comfort in Iranian office buildings. To achieve this, a questionnaire survey in six office buildings in Tehran (Iran) is conducted in conjunction with physical measurements. The study results reveal that there is a good agreement between perceived thermal sensation and calculated predicted mean vote (PMV) from the measurements for the majority of the offices (four out of six). This finding implies that the calculation of PMV is valid for the Iranian cultural situation in air conditioned and HVAC office buildings. The results also show that more than half of the studied offices are not in good compliance with the comfort levels suggested in ASHRAE Standard 55 and ISO Standard 7730.

BackgroundThere is increasing interest in the proposition that residential environment can affect mental health.AimsTo study the degree to which common mental disorder clusters according to postcode units and households. To investigate whether contextual measures of residential environment quality and geographical accessibility are associated with symptoms of common mental disorder.MethodA total of 1058 individuals aged 16–75 years (response rate 66%) participated in a cross-sectional survey The 12-item General Health Questionnaire measured symptoms of common mental disorder.ResultsOnly 2% (95% CI 0–6) of the unexplained variation in symptoms existed at postcode unit level, whereas 37% (95% CI 27–49) existed at household-level, but the postcode unit variation was reduced to zero after adjustments. There was little evidence to suggest that residential quality or accessibility were associated with symptoms.ConclusionsThere was substantial unexplained variation at the household level but we could find no evidence of postcode unit variation and no association with residential environmental quality or geographical accessibility. It is likely that the psychosocial environment is more important than the physical environment in relation to common mental disorder.

Sustainability is deeply rooted in the built environment and is inherently holistic reaching across environmental, social and economic issues at local and global scales. There is therefore a need for cross disciplinary working to ensure a sustainable approach. Although industry and government recognise the need to develop a more sustainable approach the built environment, it is slow to be achieved in practice. This paper describes the development and operation of a computer based interactive guidance system that assists with the incorporation of sustainability in built environment policies, plans, programmes and projects allowing all stakeholders to be involved. PETUS was informed by the needs of practice and designed and developed to provide a mechanism for cross disciplinary working for sustainability.

The effect of the built environment on the quality of life of its residents is of growing interest. To investigate this properly, a method for measuring the physical condition of residential areas is required and this paper describes the development of such a tool. The Residential Environment Assessment Tool (REAT) is designed as a survey instrument, to be completed by an independent observer, to produce a contextual measure of a neighbourhood, reflecting both physical aspects and also the extent to which residents have established territoriality over the area. The tool is based on 28 items which are aggregated to give a total score, ranging between 0 and 68, and subdivided into 5 different domains to reflect different aspects of the environment. Inter-observer comparisons show that the tool is reliable, with kappa coefficients for most of the item scores exceeding 0.9. To investigate its validity the results were compared with responses to a detailed survey of individual residents and significant positive associations were found between most relevant items. The tool is being used for studies involving common mental disorders in the community and should be valuable for local authorities in targeting interventions to improve the physical condition of their area.

Heat transfer process and natural ventilation driven by a solar chimney attached to a sidewall of building are investigated with CFD technique (MITFLOW) in detail. In this paper, conditions and par...

Two alternative modelling approaches, physical scale modelling and numerical simulation, have been applied to the design assessment of daylight and sunlight in, and around, high-density Hong Kong housing. The ability to include both self-shading and site obstructions is crucial to this application area, which severely constrains the methods used for both approaches. While physical scale modelling could assist in estate planning, it was not feasible to study both external and internal spaces at the same model scale, even in a large, advanced facility. Due to the need to include context surroundings, physical scale models in this application would be unlikely to be able to inform design on detailed internal conditions. Numerical simulations could effectively focus on both issues and the data produced could couple to detailed modelling of other aspects, e.g. the calculation of cooling load or peak internal temperatures. Numerical modelling at this level has significant drawbacks, however, including the investment in time and expertise necessary to achieve reliable results, and the requirement for rigorous testing and validation for general acceptance of results.

This paper describes a study of the assessment of pedestrian wind environment using two methods, namely, wind-tunnel scale modelling and numerical computational fluid dynamic (CFD) simulation. An estate of high-rise residential towers in Hong Kong is used as the test case. The two methods were found to yield broadly similar results in predicting wind-flow patterns through the complex. Wind factors of up to three times the free-site wind speed were predicted by both methods. There were, however, some disagreements in the detailed location and extent of the severe areas, which indicates further investigation and validation is required before CFD methods can be comfortably used in practice.

A clear definition of the responsibilities of the contracting parties is crucial to any contract. However, many building services maintenance contracts contain vague terms that are often causes of disputes, suspension of work, unsatisfactory performance and financial losses. Common vague contract terms include those that require the contractor to be responsible for any replacement and restoration work arising from “fair wear and tear” and “vandalism”. Reports the findings of a survey of maintenance practitioners’ interpretations of these terms, and their experience with the use of such terms in building services maintenance contracts in Hong Kong.

The 3DFLOW code has been developed based on: • The standard three-dimensional K - e two-equation turbulence model;• A modification for buoyancy effects;• Wall functions applied to deal with solid boundary conditions;• An adaptation of the SIMPLE algorithm.The representative indoor air flows in conditioned spaces, including downward mixing, partition and displacement ventilation cases, were simulated and analysed in detail using the 3DFLOW code. Good agreement was found between the numerical predictions and experimental data.

Within a given budget, selection of the optimal set of measures for enhancing the energy efficiency of a building is often based on the relative order of the feasible measures, prioritised according to either the life cycle cost saving or the economic benefit–cost ratio of the measures. A sensitivity analysis shows that, compared to the life cycle cost analysis, the benefit–cost ratio analysis is less susceptible to the influence of uncertainties in the estimates of the present value of the life cycle energy saving and cost. Where interactive measures are involved, the effects of some are dependent on the co-existence of other measures. The prioritisation determined according to the benefit–cost ratios of individual measures, each taken in the absence of all the others, can lead to the choice of a range of measures that is below optimal. Selection of the optimal set of energy efficiency enhancement measures requires a multistep approach, which is exemplified by the case study described in the paper.

This paper discusses an overall strategy for reducing energy demand in non-domestic buildings, mainly focusing on office developments. It considers four areas: reducing internal heat loads; addressing passive design through the building construction; using efficient and responsive HVAC systems and focusing on chilled (heated) surface systems; integrating renewable energy supply systems into the building design. The impact on energy use and carbon dioxide emissions will be discussed. The paper will draw from a range of design projects carried out in Europe, where this integrated approach has been applied, and then explore the benefits in relation to applications in the Middle East and China. Energy modelling results, to inform the design process will be presented, using energy simulation for three case study locations, in Zurich, the Chongqing and Abu Dhabi.

Study objective: To develop a cross disciplinary literature search methodology for conducting systematic reviews of all types of research investigating aspects of the built environment and the health of the public. Design: The method was developed following a comprehensive search of literature in the area of housing and injuries, using 30 databases covering many disciplines including medicine, social science, architecture, science, engineering, environment, planning and psychology. The results of the database searches, including the type (or evidence) of research papers identified, were analysed to identify the most productive databases and improve the efficiency of the strategy. The revised strategy for literature searching was then applied to the area of neighbourhoods and mental health, and an analysis of the evidence type of references was carried out. In recognition of the large number and variety of observational studies, an expanded evidence type classification was developed for this purpose. Main results: From an analysis of 722 citations obtained by a housing and injuries search, an overlap of only 9% was found between medical and social science databases and only 1% between medical and built environment databases. A preliminary evidence type classification of those citations that could be assessed (from information in the abstracts and titles) suggested that the majority of intervention studies on housing and injuries are likely to be found in the medical and social science databases. A number of relevant observational studies (10% of all research studies) would have been missed, however, by excluding built environment and grey literature databases. In an area lacking in interventional research (housing/neighbourhoods and mental health) as many as 25% of all research studies would have been missed by ignoring the built environment and grey literature. Conclusions: When planning a systematic review of all types of evidence in a topic relating to the built environment and the health of the public, a range of bibliographical databases from various disciplines should be considered.

Oversized equipment is one of the key factors for poor energy performance of commercial buildings in Hong Kong. Similar situations exist also in many buildings in different parts of the world. The use of realistic design criteria has been identified as an effective method to reduce the equipment oversizing problem. A set of realistic design criteria for lighting power density, occupation density, and appliances' load-intensity for various types of premises have been established based on data obtained in walk-through surveys of energy end-uses in 31 Hong Kong office buildings. Potential electricity savings through the use of realistic design criteria were estimated to be 6–22% of the electricity consumption of Hong Kong, which corresponds to an annual cost of HK$12.2–44.7 billion.

The main aim of the energy and environmental prediction (EEP) model is to provide an auditing tool for quantifying energy use and emissions in cities to assist in planning for sustainable development. The EEP model can be used as a planning and policy tool that will allow local government to select sites for development that will assist in the drive for sustainability. It can also be used as an impact assessment tool to determine the impact of proposed developments by assessing likely travel patterns and energy use. The computer-based model provides an integrative method for domestic, commercial, industrial process and transport sectors of the built environment to predict and account for energy use within a region so that plans can be made to reduce carbon dioxide and other emissions.

Many buildings in Hong Kong are equipped with oversized chiller plants, which often run at low part-load efficiency. In the paper, the conventional cooling load calculation method for plant sizing and the design criteria used in the calculation are reviewed. Factors that would contribute to overestimation of the required plant capacity are highlighted. With reference to six existing commercial buildings, design peak cooling loads estimated by using the conventional design load calculation method are compared with peak cooling loads predicted by detailed computer simulation, and with the capacities of the existing plants. In addition, the predicted energy use of the chillers based on their installed capacities are compared with the predicted energy use when the capacity of the plants are adjusted to the design cooling load determined using the conventional method, and to the peak load obtained by detailed simulation. It was found that the peak cooling load determined from a detailed simulation on the basis...

In order to inform the design of a building or a group of buildings in relation to their potential energy efficiency, the main impact will be at the initial concept design stage. Variations and interactions of parameters need to be considered quickly as the design develops. This paper describes the development of a ‘sensitivity tool’ based around the established building energy model, HTB2. An example case study from China is given to illustrate the process.

This chapter discusses the need for energy and environmental modeling at an urban scale. It stresses the importance of carrying out such modeling at an early masterplanning stage of a new development. It also considers modeling the existing built environment at urban scale and how this can inform retrofit programs. A variety of modeling methods are introduced, from simple annual energy calculations, to how more complex energy models developed for individual building simulation can be applied at an urban scale. The use of physical-scale modeling for environmental predictions is also discussed. The chapter uses a range of urban case studies to illustrate the modeling applications. Finally, a general framework for sustainable urban-scale masterplanning is introduced. The work is based on the development of urban-scale modeling tools and processes from a range of research and design projects. Learning outcomes: On successful completion of this chapter, readers will be able to: (1) explore the need for urban-scale energy and environmental modeling; (2) discuss methods of urban-scale energy and environmental modeling; (3) understand the application of modeling through case studies; and (4) appreciate the wider aspects of sustainable masterplanning.