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Advancing digitalisation and sustainability is a worldwide priority for the construction sector. With intertwined agendas, digitalisation enables the achievement of sustainable outcomes. That is the case of EU initiatives exploring building information modelling (BIM) as a facilitator to circular economy (CE). Thus, standardising BIM implementation through the ISO 19650 information requirements represents a stepping stone towards CE and achieving better sustainable outcomes. Concerning standardisation, a unified digitalisation vision is under development for the European public sector as part of the European Green Deal. However, the EU has already identified that the proposed digitalisation approach had limited effect on extensively achieving sustainable outcomes. Among the issues is the high complexity that hinders small to medium-sized enterprise (SME) construction organisations from contributing. This problem is exacerbated by the limited amount of published scientific research evidence explaining how SMEs incorporate resource-hungry digital processes into their resource-limited business models. Therefore, to understand better the digitalisation for sustainability success cases within European SMEs, this paper presents the results of a state-of-the-art literature review of academic articles, followed by a state-of-evidence review of grey literature. The focus of the review is Dutch small architectural practices (SAPs). The results highlight the importance of project information requirements for SMEs and the multifaceted digitalisation challenges experienced by SAPs and building design SMEs. This paper also suggests future research areas focusing on innovation realisation.

A growing body of literature recognises the importance of nature-based solutions in providing resilience to the effects of climate change by mitigating urban heat islands. However, a knowledge gap exists regarding the contribution of blue spaces to the urban environment. Recent evidence suggests that blue spaces within urban canyons can promote pollutant removal via the vertical transport of air under certain conditions, but this is inconclusive. Using a numerical solver that accounts for evaporation effects, we investigate the influence of blue space size and shape on the in-canyon flow structure, temperature and water vapour distribution. Simulations were performed for water bodies of varying size and shape at different temperatures compared to the surrounding air. Results suggest that inadequately sized warmer water bodies are unable to promote sufficient vertical transport for pollutant removal, leading to overturning and increased temperature and humidity levels at the pedestrian level, thereby worsening environmental conditions and increasing the risk of heat-related illness and mortality. Hence, larger water bodies are better suited to nocturnal transport of pollutants and accumulated warm air away from the urban surface, while smaller water bodies are better suited to providing localised evaporative cooling. Lastly, irregular water bodies may have a greater cooling effect across a larger area.

Buildings in the Global South are expected to drive a tripling of global cooling energy demand by 2050. In countries such as India, growth in energy use far outstrips growth in population, often to the ratio 3:1. While several building-level technologies exist that could help reduce peak and total demand, the technologies, or combination of technologies, that would offer the greatest peak reduction in the range of climates in the Global South is unknown as previous work has focused on mid latitudes. Hence, we use computer simulations to study, for the first time, six different cooling-driven peak-shaving technologies covering 19 different climates in the Global South. Using Latin Hypercube Sampling to account for the uncertainties arising from building variants and technology performance, we conduct a total of 266,000 annual hourly simulations. While thermally activated building systems and phase change materials deliver the largest reductions in peak and total demand, water storage is the most consistent in reducing the peak, yet had a possible increase in annual demand. We also develop technology combinations, or “recipes”, which suggest that the range of attainable peak and total demand reduction is between 19% - 95% and 20% - 99% respectively, depending on the climate. Given the scale of the potential reduction, our results justify the investment in such technologies by governments and others to deliver major reductions in energy demand and peak load in the Global South, but if incorrectly designed, it is clear they may result in reduced energy security and increased carbon emissions.

Around 18% of global carbon emissions can be attributed to building heating or cooling, driven by the adoption of “international” thermal comfort standards such as ASHRAE-55, which imply an homogenous indoor environment. We argue that the importation of such standards to warm climates results in indoor cold discomfort due to “overcooling”: a phenomenon anecdotally recognised worldwide but not studied or defined systematically. Unlike under- or over-heating, overcooling is the purposeful over-expenditure of energy, that creates conditions of cold thermal discomfort. We examine data for warm and temperate climates from a global thermal comfort database spanning 27 countries with over 90,000 occupant responses to investigate overcooling of air-conditioned buildings. We suggest that overcooling is best defined by taking the intersection of thermal sensation and preference and, using this definition, we find that 17% of building occupants in the examined data can be classed as being overcooled. We estimate the cooling energy demand of overcooling imposed through the adoption of the ASHRAE-55 standard using computer simulations that move building occupants from being overcooled to comfortable. The results suggest around 15% of cooling energy demand could be saved through a simple upward adjustment of set-point temperatures by 2 °C in warm climates. Such an adjustment in the Global South, which contains the majority of the warm regions of the Earth, could have a dramatic impact on the evolution of future cooling energy demand which is expected to triple by 2050.

Over the last two decades, urban geometry has been shown to be a key determinant of the microclimatic conditions in urban areas. This study uses the Ladybug-tools, the plugins of Grasshopper3D to optimise building heights, street widths and orientation to maximise outdoor thermal comfort, represented by the diurnal average Universal Thermal Climate Index (UTCI). In the hot-arid climate of Cairo, Egypt, the optimised parameters of symmetrical and asymmetrical urban canyons are compared with the Egyptian Construction Act's design regulations. The results show a strong negative correlation between the height-to-width (H/W) ratios and the output UTCI, with R² = 0.71, and much stronger (R² = 0.91) if east-west orientations are excluded from the results, exceeding correlations previously reported for Cairo. Maximum UTCI reductions due to changing H/W and orientation approach ∼6°C. Considerable variation is shown in the strength of the correlation between UTCI and the asymmetrical H/W ratio of each flank, with R² = 0.81 for Southeast side compared to R² = 0.4 for Northwest side. Design recommendations are given urban planners based on using the optimised parameters that at least achieve a UTCI reduction benchmark that exceeds those resulting from using the regulations’ thresholds.

The incorporation of nature-based solutions comprising green and blue infrastructure is often touted as a way to cool cities and enhance pollutant removal. However, there is little agreement between different methodologies to measure the effect of any single intervention. Here, we present 3D steady RANS simulations to investigate the influence of waterbody on in-canyon flow structure, temperature (T*) and water vapour (!*) distribution in a simplified urban neighbourhood. A novel solver that captures evaporation effects is developed and validated against wind tunnel experiments. Simulations are performed under neutral atmospheric conditions for forced -and mixed-convection cases and different air-water temperature differences, indicative of either daytime or night-time conditions. Results under forced convection show minimal impact on the flow structure, whilst T* and !* effects are distributed primarily over and around the water surface. However, the mixed-convection case shows that a cooler waterbody weakens the principal vortex in the open square, whilst T* and !* effects reach further upwind and are more widely distributed in the spanwise direction. A warmer waterbody is shown to disrupt the skimming flow structure, indicating a possible heat and pollutant removal mechanism from around the waterbody and also downwind canyons.

It has long been recognised that cities exhibit their own microclimate and are typically warmer than the surrounding rural areas. This 'mesoscale' influence is known as the urban heat island (UHI) effect and results largely from modification of surface properties leading to greater absorption of solar radiation, reduced convective cooling and lower water evaporation rates. Cities typically contain less vegetation and bodies of water than rural areas, and existing green and bluespace is often under threat from increasing population densities. This paper presents a meta-analysis of the key ways in which green and bluespace affect both urban canopy- and boundary-layer temperatures, examined from the perspectives of city-planning, urban climatology and climate science. The analysis suggests that the evapotranspiration-based cooling influence of both green and bluespace is primarily relevant for urban canopy-layer conditions, and that tree-dominated greenspace offers the greatest heat stress relief when it is most needed. However, the magnitude and transport of cooling experienced depends on size, spread, and geometry of greenspaces, with some solitary large parks found to offer minimal boundary-layer cooling. Contribution to cooling at the scale of the urban boundary-layer climate is attributed mainly to greenspace increasing surface roughness and thereby improving convection efficiency rather than evaporation. Although bluespace cooling and transport during the day can be substantial, nocturnal warming is highlighted as likely when conditions are most oppressive. However, when both features are employed together they can offer many synergistic ecosystem benefits including cooling. The ways in which green and bluespace infrastructure is applied in future urban growth strategies, particularly in countries expected to experience rapid urbanisation, warrants greater consideration in urban planning policy to mitigate the adverse effects of the UHI and enhance climate resilience.

Improving the energy efficiency of buildings is a key climate change mitigation strategy. The application of which will require substantial improvements in the pre-existing stock; a subset of which are buildings of historic importance. Retrofitting such buildings is controversial, as historic elements might be altered or covered up, thereby changing the character of the building. In this work, we introduce a novel socio-mathematical method to aid the resolution of this controversy. Firstly, we garner in a new way the views of 116 members of the public about the acceptability of 15 common retrofit measures. Secondly, the public's ranking of the acceptability of the measures with respect to heritage impact is compared to a ranking of the energy saving given by the measures when analysed using a dynamic thermal simulation of the building. No simple correlation is found; hence it is concluded that measures that present greater energy savings are not de facto more intrusive, and that there is the potential for a constructive dialogue between those inspired by a conservation agenda and those targeting carbon savings. Finally, by using a Pareto front approach, a new theory is developed of how to identify measures that are sensible in the eyes of both parties. This new three-stage process will be of use to those in Government attempting to resolve such conflicts or set national guidance.

The urban heat island (UHI) phenomenon represents a major public health issue and has received great attention due to rapid urbanisation. Blue spaces have long been considered a possible mitigation strategy to ameliorate the UHI. However, our knowledge regarding the interaction of waterbodies with their urban surroundings is still limited. This review attempts through a comparative analysis of the available literature to examine the thermal effects of static blue spaces on the urban climate. Remote sensing studies are the most common approach analysed in this review but there is a clear disparity between the cooling potentials reported by remote sensing as opposed to field measurements or numerical simulations, likely due to a lack of nocturnal measurements, when warming due to thermal inertia can occur and consideration of the latent heat flux. The size and shape of blue spaces are shown to be important variables for the cooling achieved in urban settings but there is no consensus in the literature. This is likely due to the different locations and climates of the studies, it can be hypothesised that in locations with an even distribution of wind directions a rounder waterbody is more effective while in locations where wind direction is more uniform an elongated waterbody aligned to the wind is more effective due to the increased fetch. From the analysis of the literature, it is clear that there is still a distinct knowledge gap regarding the physical interpretation of waterbodies' contribution to the urban climate. There is also a current lack of information about the diurnal and seasonal variability of the various structures and processes. There is evidence, however, that the comfort achieved by sensible cooling can be offset by the increased water vapour content and that during the night blue spaces may actually exacerbate the UHI, reducing urban thermal comfort.

This book provides a detailed overview of the risks associated with climate change for urban areas, including those risks to human health as well as to building integrity, the physical processes involved, and presents key information in which way the risks can be reduced and urban areas made more resilient.

This article provides the first comprehensive assessment of methods for the creation of weather variables for use in building simulation. We undertake a critical analysis of the fundamental issues and limitations of each methodology and discusses new challenges, such as how to deal with uncertainty, the urban heat island, climate change and extreme events. Proposals for the next generation of weather files for building simulation are made based on this analysis. A seven-point list of requirements for weather files is introduced and the state-of-the-art compared to this via a mapping exercise. It is found that there are various issues with all current and suggested approaches, but the two areas most requiring attention are the production of weather files for the urban landscape and files specifically designed to test buildings against the criteria of morbidity, mortality and building services system failure. Practical application: Robust weather files are key to the design of sustainable, healthy and comfortable buildings. This article provides the first comprehensive assessment of their technical requirements to ensure buildings perform well in both current and future climates.

Both the Paris heat wave of 2003 and recent high-resolution climate change predictions indicate a world where mortality from extreme weather events will increase. Most heat wave deaths occur in buildings, and are driven by the thermal characteristics of the buildings and their local environment. Unfortunately previous work on the topic has ignored such spatial variations by either assuming the climate has little variation over a large area, or using archetypes of buildings from stock models. The latter forgetting that neither building characteristics nor landscape context are uniform over a city, with for example suburbs having a different architecture and shading to the inner city. In this work we use a statistical method combined with a new remote surveying tool to assemble accurate models of real buildings across a landscape then map the spatial variability in overheating and excess deaths now and in the future at a resolution of 5 km × 5 km. High spatial variation in the risk of overheating and heat-related mortality was found due to the variability of architecture, context and weather. Variability from the architecture and shading context were found to be a greater influence on the spatial variation in overheating than climate variability. Overheating risk was found to increase significantly with heat-related mortality tripling by the 2050s. The method was validated against data collected during the northern hemisphere 2006 hot summer. The maps produced would be a highly useful resource for government in identifying populations of greatest concern when developing policies to combat such deaths.

Rainwater harvesting (RWH) systems are increasingly being implemented in buildings. It is common in the UK for simple RWH tank sizing methods to be utilised, and these do not consider future climate change. This paper describes the development of a tool, which integrates elements of basic and detailed sizing approaches from the British Standard for RWH, with the latest probabilistic UK Climate Projections data. The method was initially applied to the design of a university building in Cornwall, UK. The methodology utilises 3,000 equi-probable rainfall patterns for tank sizing for each time period. Results indicate that, to ensure that it is ‘likely’ that the same non-potable demand could be met in 2080 as in the present, a tank 112% larger would be required. This increases to a 225% over-sizing for a ‘very likely’ probability of meeting the same level of non-potable demand. The same RWH system design was then assessed for three further UK locations with different rainfall characteristics. From these assessments, a simplified method was developed to enable practitioners to size RWH system tanks for current and future climates. The method provides a new approach to meet present and future non-potable demands, while preventing excessive over-sizing of tanks.

The climate in cities differs significantly from those found in the surrounding area. These differences results from modifications of the Earth's surface that alters the disposition of “natural energy balance” at a micro-scale and the concentration of activities that results in anthropogenic emissions that change the composition of the atmosphere. These urban effects have distinctive temporal and spatial properties with different impacts on building energy performance depending on their purpose which are rarely accounted for. This paper examines performance implications of a change-of-use (from office to residential) in the context of the UK government's proposal to encourage regeneration and to meet housing needs. However, the diurnal occupation and activity patterns of these uses are distinct. For office buildings, with daytime occupation, focus is on the diurnal heating cycle driven by solar energy gains to which internal energy sources must be added. For residential buildings occupation and activity are primarily associated with the diurnal cooling period, and lower levels of activity that results in a primary heating need. This paper highlights the link between the timing of the urban climate effects, the urban setting and energy performance in a typical city street, where buildings are currently designed for commercial use. It employs London's current and projected climate to simulate heating and cooling demands. By studying the role of urban form and its implications on the suitability of a buildings function we find that a ‘form first’ approach should be considered in the early design stages over the standard ‘fabric first’ approach.

Building designers rely on a plethora of design guidance beyond compulsory building codes or regulations. However, it has been noted that guidance can be conflicting or contradictory. There is also evidence that design teams opt for ‘the safe option’, or that which colleagues have used. This is known to have led to the over-engineering of buildings and systems, potentially leading to unnecessary energy use, in direct conflict with the low carbon agenda. To quantify the potential scale of the impact, we investigated the energy use of commercial swimming pool halls, using the full-range of common design standards. Swimming pools were chosen due to their high-energy demand and because there are many guidance documents available from different sources. We found that different standards (which revolve around temperature, humidity and ventilation rate) produce designs with very different energy consumptions. Furthermore, the optimal ventilation rate (derived from a physics-based approach) was found to be far from values presented in guidance documents. Use of this new rate implies a 90% reduction in energy use, compared to the most conservative guidance, confirmed using measured data. This suggests this is a real issue and the existence of such contradictory guidance runs against the low carbon agenda.

As the 2003 Paris heatwave showed, elevated temperatures in buildings can cause thousands of deaths. This makes the assessment of overheating risk a critical exercise. Unfortunately current methods of creating example weather time series for the assessment of overheating are based on a single weather variable, and hence on only one driver of discomfort or mortality. In this study, two alternative approaches for the development of current and future weather files are presented: one (pHSY-1) is based on Weighted Cooling Degree Hours (WCDH), the other (pHSY-2) is based on Physiologically Equivalent Temperature (PET). pHSY-1 and pHSY-2 files were produced for fourteen locations. These were then compared with the existing probabilistic future Design Summer Year (pDSY) and the probabilistic future Test Reference Year. It was found that both pHSY-1 and pHSY-2 are more robust than the pDSY. It is suggested that pHSY-1 could be used for assessing the severity and occurrence of overheating, while pHSY-2 could be used for evaluating thermal discomfort or heat stress. The results also highlight an important limitation in using different metrics to compare overheating years. If the weather year is created by a ranking of a single environmental variable, to ensure consistent results assessment of the building should be with a similar single metric (e.g. hours >28 °C or WCDH), if however the weather year is based upon several environmental variables then a composite metric (e.g. PET or Fanger’s PMV) should be used. This has important implications for the suitability of weather files for thermal comfort analysis.

To allow building scientists and engineers to investigate how their building designs fare in future climates there is the need for future weather files on an hourly timescale, which are representative of possible future climates. With the publication of the most recent UK Climate Projections (UKCP09) such data can be created for future years up to the end of the 21st century and for various predictions of climate change by one of two methods: mathematical transformations of observed weather (morphing), or the use of a synthetic weather generator. Here current and future weather is created by both of these methods for three locations within the UK and their statistical signatures discussed. Although the potential to use both products to investigate the effects of climate change is clear, it is found that the use of UKCP09 climate change anomalies within the morphing procedure give an unrealistic representations of future temperatures both mathematically and physically, limiting its use.

Given a changing climate, there is a need to provide data for future years so that practicing engineers can investigate the impact of climate change on particular designs and examine any risk the client might be exposed to. In addition, such files are of use to building scientists in developing generic solutions to problems such as elevated internal temperatures and poor thermal comfort. With the release of the UK Climate Projections (UKCP09) [1], and the publication of a methodology for the creation of probabilistic future reference years using the UKCP09 weather generator [2], it is possible to model future building performance. However, the collapse of the distribution of possibilities inherent in the UKCP09 method into a single reference year or a small number of reference years, potentially means the loss of most of the information about the potential range of the response of the building and of the risk occupants might be subject to. In this paper we model for the first time the internal conditions and energy use of a building with all 3000 example years produced by the UKCP09 weather generator in an attempt to study the full range of response and risk. The resultant histograms and cumulative distribution functions are then used to examine whether single reference years can be used to answer questions about response and risk under a changing climate, or whether a more probabilistic approach is unavoidable.

The present research explored beliefs about climate change among an important yet relatively understudied population: representatives of the building industry. We also assessed the perceived adequacy of current climate-related actions within the industry and the perceived need for developing new practices. The results of a survey administered within a large engineering firm suggest a fairly high level of concern about climate issues within this sector: participants perceived climate change to be an important issue, current practices to be inadequate, and a need to develop new ways of addressing climate change. Despite this, there was notable and consequential variability in how participants thought about climate change. Higher levels of seniority were associated with greater satisfaction with current practices, and the belief that climate change was a natural rather than man-made phenomena was associated with a reduced support for the idea that changes to current practices were necessary. In addition, when thinking about climate relevant actions (whether current practices or the alternatives) participants focussed almost exclusively on mitigation rather than adaptation. The implications of these patterns for innovation around climate change within the building industry are discussed.

Pseudo weather data with a high temporal resolution are of use in many fields including the modelling of agricultural systems, the placement of wind turbines and building thermal simulations. With the publication of the 2009 UK Climate Projections (UKCP09) such data can be created for future years and for various predictions of climate change. Unfortunately such — UKCP09 — data does not include information about wind speed or direction due to a lack of robustness. Here we demonstrate a methodology for generating such wind data on an hourly time grid from a consideration of the potential evapotranspiration reported by the UKCP09 weather generator and information related to the correlation between observed wind speed, direction and time of year. We find our pseudo wind data is consistent with the historic observed wind. Furthermore, when used within a dynamic thermal simulation of a building, the use of such pseudo wind data generates a consistent internal environment in terms of ventilation rates, temperatures and energy use that is indistinguishable from simulations completed using historic observed weather for both single-sided and cross-ventilated buildings. Practical applications: The methodology presented in this paper will allow academics and building engineers to create realistic hourly wind speed and direction data for inclusion with the future climate data of UKCP09. This will allow the creation of consistent future weather years for use in areas such as building thermal simulation.

Buildings are generally modelled for compliance using reference weather years. In the UK these are the test reference year (TRY) used for energy analysis and the design summer year (DSY) used for assessing overheating in the summer. These reference years currently exist for 14 locations around the UK and consist of either a composite year compiled of the most average months from 23 years worth of observed weather data (TRY) or a single contiguous year representing a hot but non-extreme summer (DSY). In this paper, we compare simulations run using the reference years and the results obtained from simulations using the base data sets from which these reference years were chosen. We compare the posterior statistic to the reference year for several buildings examining energy use, internal temperatures, overheating and thermal comfort. We find that while the reference years allow rapid thermal modelling of building designs they are not always representative of the average energy use (TRY) exposed by modelling with many weather years. Also they do not always give an accurate indication of the internal conditions within a building and as such can give a misleading representation of the risk of overheating (DSY). Practical applications: An understanding of the limitations of the current reference years is required to allow creation of updated reference years for building simulation of future buildings. By comparing the reference years to the base data sets of historical data from which they were compiled an understanding of the benefit of multiple simulations in determining risk can be obtained.

With the increasing threat of serious climate change, various governments are aiming to substantially reduce their carbon emissions. In the UK all new schools and domestic buildings are required to be ‘zero-carbon’ from 2016. Schools are seen as community centres of activity and learning by local authorities, as such there is an emphasis to make schools exemplar buildings within the community and demonstrate best practice with regards to low and zero-carbon design. This paper focuses on what are the pertinent drivers and obstacles to low carbon school design based upon literature review and a survey of experts in the field. We find that more barriers are identified than drivers for low carbon design, with the greatest drivers being legislation, environmental concerns and running costs. The greatest barriers were identified as increased equipment in modern schools, complexity of building systems and the perceived extra cost of low carbon design and technologies. It is suggested that most barriers could be overcome by improving communication between the design team, client and end users, and that truly integrated design teams are the key to mainstream low carbon school design.

The impacts of climate change pose many threats to our current way of life. However, the current mitigation agenda has not yet produced the carbon emission reductions needed implying that some level of adaptation will be required. For buildings this is likely to mean either drastic changes to architecture, occupant behaviour or the increased use of artificial cooling to maintain thermal comfort in the future. The capital cost of sustainable buildings is often perceived to be higher than for conventional buildings and there is little incentive to employ sustainable building adaptations over air-conditioning type solutions, making future reductions in carbon emissions unlikely. In this paper we investigate contributing factors to worker productivity in an attempt to justify the perceived cost of sustainable adaptations. Then as a proof of concept we estimate the potential savings that could be achieved by applying two simple adaptations to an office building to produce a more comfortable environment. It is hoped that this consideration of loss of productivity and its causes will aid not only in the choice of useful adaptation decisions, but also a consideration of payback periods will help persuade building commissioners of their value and overcome the perceptions about sustainable buildings.

The uncertainty surrounding projections of climate change has left the building design community in a quandary. Should they assume a worst case scenario, and recommend adaptations to designs that might prove to be unnecessary and quite possibly costly? Or should they increase the risk to the occupants by selecting a less pessimistic vision of the future? It is well known that structural adaptations, such as additional thermal mass, can help moderate internal conditions as can behavioural adaptations, such as opening windows. Here the relative magnitudes of structural and non-structural (behavioural) adaptations are reflected upon, with the specific intent of discovering whether non-structural adaptations might have a great enough effect to offset any errors from selecting what proves to be (in 40 years time) an erroneous choice of climate change projection. It is found that an alteration to how a building is used is as equally important as common structural adaptations, and that the risk of choosing what turns out to be an incorrect climate change projection can be dealt with by seeing non-structural adaptations as a way of nullifying this risk.

Building thermal modelling packages require weather data to predict representative internal conditions. Typically, around the world, reference weather years of various forms are used which are created from observations at aparticular location. However, it is unlikely that this location is identical to that of the building. This can lead toweather files for coastal locations being applied to inland and upland sites or vice versa. In the UK, the UKCP09 weather generator has the ability to produce weather at a 5 km resolution. Currently, it is unclear how useful this extra spatial resolution will be and it is this question that is addressed here. It is found that for both future and present climate, the spatial variability of the weather is the dominating factor. Although there are geographies where a low spatial resolution can be used, there are regions where a much higher resolution is necessary.

Weather data are used extensively by building scientists and engineers to study the performance of their designs, help compare design alternatives and ensure compliance with building regulations. Given a changing climate, there is a need to provide data for future years so that practising engineers can investigate the impact of climate change on particular designs and examine any risk the commissioning client might be exposed to. In addition, such files are of use to building scientists in developing generic solutions to problems such as elevated internal temperatures and poor thermal comfort. With the publication of the UK Climate Projections (UKCP09) such data can be created for future years up to 2080 and for various probabilistic projections of climate change by the use of a weather generator. Here, we discuss a method for the creation of future probabilistic reference years for use within thermal models. In addition, a comparison is made with the current set of future weather years based on the UKCIP02 projections. When used within a dynamic thermal simulation of a building, the internal environments created by the current set of future weather files lie within the range of the internal environments created by the probabilistic reference years generated by the weather generator. Hence, the main advantages of the weather generator are seen to lie in its potentially greater spatial resolution, its ability to inform risk analysis and that such files, unlike ones based on observed data, carry no copyright. Practical applications: The methodology presented in this article will allow academics and buildings engineers to create realistic hourly future weather files using the future climate data of UKCP09 weather generator. This will allow the creation of consistent future weather years for use in areas such as building thermal simulation.

Recent studies of the electronic properties of graphite have produced conflicting results regarding the positions of the different carrier types within the Brillouin zone, and the possible presence of Dirac fermions. In this paper we report a comprehensive study of the de Haas--van Alphen, Shubnikov--de Haas, and Hall effects in a sample of highly orientated pyrolytic graphite, at temperatures in the range 30$ $mK to 4$ $K and magnetic fields up to 12$ $T. The transport measurements confirm the Brillouin-zone locations of the different carrier types assigned by Schroeder, Dresselhaus, and Javan, Phys. Rev. Lett. 20, 1292 (1968): electrons are at the $K$ point, and holes are near the $H$ points. We extract the cyclotron masses and scattering times for both carrier types from the temperature- and magnetic-field-dependences of the magneto-oscillations. Our results indicate that the holes experience stronger scattering and hence have lower mobility than the electrons. We utilize phase-frequency analysis and intercept analysis of the $1/B$ positions of magneto-oscillation extrema to identify the nature of the carriers in graphite, whether they are Dirac or normal (Schr\"odinger) fermions. These analyses indicate normal holes and electrons of indeterminate nature.

Cities are known to exert a significant influence on their local climate, and are generally warmer than their surroundings. However, climate models generally do not include a representation of urban areas, and so climate projections from models are likely to underestimate temperatures in urban areas. A simple methodology has been developed to calculate the urban heat island (UHI) from a set of gridded temperature data; the UHI may then be added to climate model projections and weather data files. This methodology allows the UHI to be calculated on a monthly basis and downscaled to hourly for addition to weather generator data. The UHI intensities produced are found to be consistent with observed data. Practical application: There is overwhelming consensus amongst the scientific community that the Earth’s climate is warming. In addition to the effects of climate change the urban heat island (UHI) effect can increase air temperatures significantly in urban areas above those of the rural areas around them. The proposed methodology for calculating the UHI from a set of gridded temperature data allows the UHI to be added to climate model projections such as UKCP09 or HadRM3 and weather data files. The methodology also allows for the temporal downscaling of the UHI from monthly values to hourly data for use in building thermal simulation software.

In August 2003, 14,800 heat-related deaths occurred in Paris [1] during what is considered the warmest summer since at least 1500 [2] , [3] , [4] , [5] . These deaths resulted not only from unusually high peak temperatures and a reduction in the diurnal temperature swing, but also from a failure of buildings to successfully modify the external environment. It has been estimated [6] that by the 2040s, a 2003-type summer is predicted to be average within Europe. Clearly this will have a great impact on morbidity and mortality and produce challenges for emergency services [7] . The effects of climate change on the internal environment are not well known and are the subject of much current research [8] . For building scientists and emergency planners, there is the need to know the general form of the relationship between increases in external temperature due to climate change and increases in internal temperatures. Here we show that the relationship is linear, and that differing architectures give rise to differing constants of proportionality. This is a surprising result as it had been assumed that, given the complexity of the heat flows within large structures, no simple relationship would exist and had not been found in previous work [9] . We term these constants of proportionality climate change amplification coefficients. These coefficients fully describe the change in the internal environment of an architecture given a seasonal or annual change in external climate and can be used to judge the resilience to climate change of a particular structure. The estimation and use of these coefficients for new or existing buildings will allow: the design of more resilient buildings adapted to a changing climate, cost-benefit analysis of refurbishment options and the rational assembly of at-risk registers of vulnerable building occupants.

The decay of quasi-persistent circulating currents in the dissipationless quantum Hall regime has been observed. The currents induced by a time-varying magnetic field flow within a two-dimensional electron system (2DES) embedded in a GaAs–(Al,Ga)As heterojunction. The associated magnetic moment is measured using a highly sensitive magnetometer. The currents are observed to continue circulating for many hours after the magnetic field sweep is stopped indicating a very low sheet resistivity. Two distinct current decay regimes are observed, consisting of an initial exponential decay lasting a few tens of seconds followed by a much slower power-law decay. The presence of the fast initial decay, during which the current falls typically to half of its original value, indicates that the system is initially quite dissipative because the quantum Hall effect (QHE) has broken down due to the large induced current. As the current decays, the quasi-dissipationless QHE state recovers, resulting in the much slower decay, which the data suggest will persist for at least several days, much longer than has previously been suggested. The power-law form of the long decay suggests multiple relaxation paths for the system to return to equilibrium, each having a different characteristic time constant. This can equivalently be thought of as a resistivity which gradually falls with current.

There is a growing desire to reduce peak temperatures within non–domestic buildings by accessing the thermal mass of separating floors. These floors are typically formed of concrete and can store reasonable amounts of heat. Unfortunately, they are usually thermally isolated from the room below by a suspended ceiling. Therefore, some architects try to access the concrete by leaving a perimeter gap in the suspended ceiling in each room to allow airflow across the underside of the separating floor. For visual and acoustic reasons, there is the desire to make this gap as small as possible. Using computational fluid dynamics we examine the relationship between gap size and airflow above the suspended ceiling for naturally ventilated spaces.We show that although the precise details of the airflow depends on the size of the room, levels of incidental gains, ventilation rates and the location of heat sources, in all cases increasing the perimeter width within realistic bounds results in a linear increase ...