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Reducing greenhouse gas emissions in the built environment is key to mitigating climate change. This paper uses Life Cycle Assessment (LCA) to explore whether glue-laminated timber (glulam) has a significantly lower whole-life embodied carbon (Global Warming Potential; GWP) than functionally-equivalent structural steel. Alongside a baseline assessment that follows standard practice, a variety of further sensitivity analyses establish how differing assumptions affect results. Assessment found that the GWPs were highly dependent on: (1) the assumed end-of-life scenarios; (2) the approach used to consider biogenic CO2, and; (3) whether the timing of emissions was considered. In general, glulam had the lowest GWP when incinerated (with energy recovery) at end-of-life. However, when recycling is modelled according to current standards, glulam GWPs were in amongst those of steel, giving no clear ranking of materials. Landfilled glulam had a lower GWP than steel if some biogenic carbon was assumed to be permanently stored. That may be appropriate given recent guidance from the Intergovernmental Panel on Climate Change, but is not allowed in the updated standards for LCA of construction products (e.g. EN 15804:2019). Six additional impact categories were also assessed to give a broader environmental comparison. The relative impact of the two materials depended on the impact category assessed, with glulam generally having a similar or lower impact than steel. Given the findings of this paper, further research on end-of-life treatment and LCA methodology is critical to ensure that strategies aiming to reduce GWP by material selection are effective in practice.

Urban building-stocks are responsible for a significant share of resource and energy use. To quantify the potential for reducing energy and environmental impact, building-stock modelling (BSM) is commonly used. Recently, the focus of BSM has expanded to include environmental impacts and life-cycle assessment (LCA). However, impact categories are often limited to climate change and representative buildings are often used. In addition, the future state of the stock is often calculated as a step-change to highlight the technical potential of an ideal future state. The aim of this paper is to assess the environmental impact of the future development of an urban housing-stock under business-as-usual scenarios using a building-specific GIS based model applied to the multi-family building stock of the City of Gothenburg. This paper uses an explorative LCA to account for environmental impacts based on dynamic uptake of common renovation measures and resulting energy savings until 2050. Two main scenarios are used where the renovation logic is based on either end-of-life of components or cost-effectiveness and further divided using limiting factors regarding investment capacity and annual share of the stock to be renovated. Results show possible energy savings of up to 23% and a corresponding 31% reduction in greenhouse-gas emissions. Greenhouse-gas emissions avoided due to reduced energy demand are offset by up to 65% by accounting for material use due to construction related renovation measures. For scenarios that favour construction related interventions, PV panels are responsible for the major part of the environmental impact across the 15 mid-point indicators used.

In view of the warming climate, there is increasing concern about the likelihood of overheating inside UK buildings that are not mechanically cooled. A number of studies are examining this matter, of which the DeDeRHECC project is one. The recent availability of the UKCP09 future climate data projections has acted as a stimulus to such work. This paper illustrates how field measurement, thermal modelling and the generation of current and future typical and extreme weather years, can be used to provide a picture of the resilience of buildings to climate change. The unified framework for assessing both measurements and current and future predictions that is offered by the BSEN15251 thermal comfort standard is a crucial component. The paper focuses on internal temperatures during the day and at night in wards within the tower building at Addenbrooke’s hospital, which has a hybrid ventilation strategy. The maintenance of thermal comfort in such spaces is critically important and installing air-conditioning in response to climate change is expensive and potentially energy intensive. Fans appear to be a simple retrofit measure that may substantially improve the wards’ resilience to climate change even in extreme years. Whilst healthcare provides the back cloth, the methodology developed has a much wider utility for assessing thermal comfort in buildings in the current and future climate of the UK.

Thermal comfort of people in outdoor urban spaces is a growing concern in cities due to climate change and urbanization. In outdoor settings the climate and behavior of people are more dynamic than in indoor situations, therefore a steady state of the thermoregulatory system is rarely reached. Understanding the dynamics of outdoor thermal comfort requires accurate predictive models. In this paper we extend a classical two-node model of human body thermal regulation. We give a detailed description and interpretation of all the components and parameter values and test the dynamics of the model against experimental data. We propose a modification of the skin blood flow model which, while keeping realistic values and responsiveness, improves skin temperature prediction nearly fourfold. We further analyze the sensitivity of the model with respect to climatic and personal parameters. This analysis reveals the relative importance of, for instance, air temperature, wind speed and clothing, in thermoregulatory processes of the human body in various climatic settings. We conclude, that our model realistically reproduces the dynamics of aggregate measures of human body thermal regulation. Validated for cool, warm and hot environments, the model is shown to be accurate in terms of its dynamics and it is conceptually and computationally far more efficient than any existing multi-node and multi-part model. NRF (Natl Research Foundation, S’pore) Accepted version

Overheating in buildings has been identified as an essential cause of several problems ranging from thermal discomfort and productivity reduction to illness and death. Overheating in buildings is expected to increase as global warming continues. The risk of overheating in existing and new buildings can be reduced if policy makers take decisions about adaptation interventions quickly. This paper introduces a methodology for supporting such decisions on a national level. The methodology aims at (i) quantifying the impact of climate change on the overheating risk, (ii) ranking and characterizing the various building types in terms of their overheating risk and sensitivity to climate change, and (iii) assessing the potential of ventilative cooling to mitigate the effects of climate change. In the case study the overheating risk is evaluated in thousands of dwelling cases (i.e., 9216 possible combinations of several design and operation strategies) consistent with the characteristics of the Dutch dwelling stock built between 1964 and 2013. The overheating risk is assessed for four climate scenarios, which represent historical and future scenarios developed by the Royal Netherlands Meteorological Institute. Computational analyses are carried out using the detailed building performance simulation program IDA-ICE, assisted by a postprocessing calculation model developed in MATLAB ® . The results show that most of the Dutch dwelling types can effectively suppress the effects of global warming. However, poorly ventilated dwellings are vulnerable to overheating and are the most sensitive to climate change, particularly if their windows are not well protected against direct solar radiation.

Both the construction and use of buildings cause significant environmental pressures. The greenhouse gas (GHG) emissions imposed by buildings have been studied rather extensively, but less is known about other impacts. Still, climate change is only one harmful impact driven by buildings. Furthermore, no studies exist about how the other impacts are correlated with GHG emissions in the building context, and thus to what extent GHGs could be utilized as a more general environmental performance indicator. This paper fills these gaps by presenting a life cycle assessment of the pre-use phase of a modern concrete-element residential building with a very comprehensive life cycle inventory (LCI). The focus of the study is on the comparison of the accumulation of different environmental impacts relative to GHGs. The accumulation is analyzed from two perspectives common to building LCAs: building systems and different construction materials. The ReCiPe midpoint assessment method is utilized to reach wide impact category coverage. The study shows how GHGs act as a relatively good indicator for eight impact categories, but not for the others. The study also depicts that a very high coverage in the LCI must be reached to capture the majority of the different impacts. Many materials and building systems are considered non-relevant and are often excluded from building LCAs, which are in fact of great importance in many impact categories, The Academy of Finland (Grant 286747), Peer reviewed pre-print, Ritrýnt tímarit

This paper reports on temporal and spatial variability of local climate and outdoor human thermal comfort within the Rotterdam agglomeration. We analyse three years of meteorological observations (2010–2012) from a monitoring network. Focus is on the atmospheric urban heat island (UHI); the difference in air temperature between urban areas and rural surroundings. In addition, we calculate the Physiologically Equivalent Temperature (PET) which is a measure of thermal comfort. Subsequently, we determine the dependency of intra-urban variability in local climate and PET on urban land-use and geometric characteristics. During a large part of the year, UHI-intensities in densely built areas can be considerable, under calm and clear (cloudless) weather conditions. The highest maximum UHI-values are found in summer, with 95-percentile values ranging from 4.3 K to more than 8 K, depending on the location. In winter, UHI-intensities are generally lower. Intra-urban variability in maximum UHI-intensity is considerable, indicating that local features have an important influence. It is found to be significantly related to building, impervious and green surface fractions, respectively, as well as to mean building height.In summer, urban areas show a larger number of discomfort hours (PET > 23 °C) compared to the reference rural area. Our results indicate that this is mainly related to the much lower wind velocities in urban areas. Also intra-urban variability in thermal comfort during daytime appears to be mainly related to differences in wind velocity. After sunset, the UHI effect plays a more prominent role and hence thermal comfort is more related with urban characteristics.

Global warming and elevated temperatures in the Netherlands will increase the energy demand for cooling. Studying passive strategies to cope with the consequences of climate change is inevitable. This paper investigates the thermal performance of courtyard dwellings in the Netherlands. The effects of different orientations and elongations, cool roofs and pavements on indoor thermal comfort are studied through simulations and field measurements. The results show that North-South and East-West orientations provide the least and most comfortable indoor environments. Regarding materials, the use of green on roofs and as courtyard pavement is the most effective heat mitigation strategy. It was observed that the effects of wet cool roofs are much higher than of dry roofs. Cool roofs did not show a specific negative effect (heat loss) as compared to conventional asphalt roofs in winter. Some simulation results were validated through field measurement with a 0.91 °C root mean square deviation.

In response to UK government policy mandating the construction of ‘zero carbon’ homes by 2016 there have been significant changes in the way dwellings are being designed and built. Recent years have seen a rapid uptake in the adoption of the German Passivhaus standard as a template for ultra-low energy and zero carbon buildings in the UK. Despite genuine motivations to mitigate climate change and fuel poverty there is a lack of research investigating the long-term performance of Passivhaus buildings in a rapidly changing UK climate. This paper sets out to investigate whether Passivhaus dwellings will be able to provide high standards of thermal comfort in the future or whether they are inherently vulnerable to overheating risks. Scenario modelling using probabilistic data derived from the UKCP09 weather generator (WG) in conjunction with dynamic simulation and global sensitivity analysis techniques are used to assess the future performance of a range of typical Passivhaus dwellings relative to an identical Fabric Energy Efficiency Standard (FEES) compliant dwelling over its notional future lifespan. The emphasis of this study is to understand what impact climate change will pose to overheating risks for Passivhaus dwellings relative to the de facto (i.e. FEES) alternative, and which design factors play a dominant role in contributing to this risk. The results show that optimization of a small number of design inputs, including glazing ratios and external shading devices, can play a significant role in mitigating future overheating risks.

Building surface erosion is a common phenomenon observed on historic building facades due to wind-driven rain (WDR) impact. Recently, studies on climate change and the effect this might have on increased extreme rainfall events has renewed the scientific interest on determining the risk of accelerated erosive effects. Given the fact that WDR loads on building facades is proportional to rainfall and represents the main moisture source and erosive physical impact for building facades, an assessment method that quantifies the severity of erosion is the first step towards recommending remedial measures. The paper discusses the major factors escalating the gradual loss of surface material, considering value, hazard, vulnerability and exposure in order to examine the WDR drop impact on the aesthetic significance and the structural integrity of heritage buildings, within a parametric framework. The study investigates the effects of different size water drops, with different impact speeds on a range of masonry materials with different surface asperities and varying moisture absorption features, at various impact angles. For the relative quantification of the long-term surface erosion, straightforward and globally adaptable experiments are proposed based on site-specific climatic data and materials. Finally, strength decline of exposed sample units proves the strength-degrading effect of erosive WDR.

With a growing global concern about climate change, the building industry is facing the question of how predicted changes in climate will impact on the performance of buildings around the world. This is resulting in a fast-growing field of research that focuses on the adaptation and resilience of buildings to a changing climate. This review paper sets the scene for a special issue of Building and Environment on this subject. It discusses the relationship between climate change and buildings and the emerging body of knowledge on the subject, as well as classifying and summarizing the contributions to this special issue.

Recent activity in the development of future weather data for building performance simulation follows recognition of the limitations of traditional methods, which have been based on a stationary (observed) climate. In the UK, such developments have followed on from the availability of regional climate models as delivered in UKCIP02 and recently the probabilistic projections released under UKCP09. One major area of concern is the future performance and adaptability of buildings which employ exclusively passive or low-energy cooling systems. One such method which can be employed in an integral or retrofit situation is direct or indirect evaporative cooling. The effectiveness of evaporative cooling is most strongly influenced by the wet-bulb depression of the ambient air, hence is generally regarded as most suited to hot, dry climates. However, this technology has been shown to be effective in the UK, primarily in mixed-mode buildings or as a retrofit to industrial/commercial applications. Climate projections for the UK generally indicate an increase in the summer wet-bulb depression, suggesting an enhanced potential for the application of evaporative cooling. The paper illustrates this potential by an analysis of the probabilistic scenarios released under UKCP09, together with a detailed building/plant simulation of case study building located in the South-East of England. The results indicate a high probability that evaporative cooling will still be a viable low-energy technique in the 2050s.

Cities are expected to experience an increasing risk of overheating due to climate change and the urban heat island phenomenon. Although external factors, such as urban morphology and greening, may influence the spatio-temporal variation of overheating risk, the individual building characteristics are also likely to be important. This paper presents the results of EnergyPlus dynamic thermal simulations of 3456 combinations of dwelling types and characteristics selected to represent the London domestic stock. Two Design Summer Year weather files were used to represent the current and future climate: the CIBSE 1984–2004 and a UKCP09 future weather file (50th percentile of external temperature, 2050s, medium emissions scenario). Appreciable variation between dwelling types but generally greater variation within dwelling type was found depending on such factors as orientation, surrounding buildings and insulation levels. Under the current climate, the insulation levels had considerable impact on indoor temperatures, with combined retrofitting of roof insulation and window upgrades reducing daytime living room temperatures during the warmest continuous 5-day period of modelling by, on average, 0.76 °C (%95C.I. 0.63, 0.89 °C) for mean temperature and 1.30 °C (%95C.I. 1.05, 1.54 °C) for maximum temperature. On the other hand, internally retrofitted walls and floors tended to increase daytime living room temperatures, with a combined effect of 0.46 °C (%95C.I. 0.33, 0.60 °C) increase in mean temperature and 0.71 °C (%95C.I. 0.47, 0.96) increase in maximum temperature. Within the context of a changing climate, knowledge of insulation characteristics after retrofitting is crucial for the accurate identification of dwellings with greatest overheating potential.

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.

Computer simulation of buildings and solar energy systems is being used increasingly in energy assessments and design. Simulation often requires hourly weather data. Such data sets are the Test Reference Years (TRYs), Typical Meteorological Year (TMY) and Weather Year for Energy Calculations (WYEC). Typical weather data consists of 8760 values of various selected meteorological parameters such as ambient temperature, solar radiation, relative humidity and wind velocity and are originally derived from long-term data. This paper discusses methods of selecting typical weather data, the possibility of using the cloud cover data instead of daily global radiation and describes the selection of ISO Test Reference Year (TRY) for major cities of South Korea. The ISO-15927 procedure and algorithms are explained in detail and the Finkelstein–Schafer statistic, the basic selector statistic explained. ISO TRYs for the major cities of South Korea are derived from 20 years of meteorological data recorded during the period 1986–2005. A comparison is made between the 7 sites demonstrating the link between dry-bulb temperature, solar radiation and latitude.