The process of building design is currently undergoing some major changes. In an attempt to mitig... more The process of building design is currently undergoing some major changes. In an attempt to mitigate climate change, the design of more sustainable building is advocated by the UK government. Furthermore, standalone design methods are being replaced with the concept of Building Information Modelling (BIM). The adoption of BIM has been documented to result in many benefits, which range from time to cost savings. During the initial planning stages, building performance simulation (BPS) can be used to inform design decisions. Data can be exchanged between BIM and BPS tools using data transfer schemas such as the Industry Foundation Classes (IFC). The IFC schema lacks an energy domain, and as a result, an extension is proposed in this paper. This contains energy concepts from a BPS tool called Passive House Planning Package (PHPP). The extended schema was developed by way of an externally coupled Java tool, which facilitates the transfer of data, and informs the building design decision-making process. The process of geometry extraction has been validated with several case studies, which are based on certified Passivhaus buildings in Hannover Kronsberg, Germany and Ebbw Vale, Wales. The amount of error is acceptable, and it is mostly due to differences in the initial BIM model set up, not due to the processing of IFC files.
Driven by Climate Change legislation and high rates of fuel poverty, the UK faces multiple challe... more Driven by Climate Change legislation and high rates of fuel poverty, the UK faces multiple challenges both in new build and upgrading the existing stock. How these challenges are addressed will have long term impacts on building fabric, occupant comfort and wellbeing. Building performance simulation has an important role to play in this process, yet it is widely recognised that oversimplification in the modelling of physical phenomena leads to substantial sources of error. Moisture is a major cause of damage in buildings, and the Glaser method is a widely used steady-state method used to calculate the vapour pressure difference in a building's envelope. Although known for its limitations, it is the principal method used to assess moisture response in the UK. This paper evaluates the current situation in the UK, addressing fuel poverty targets, energy saving regulations and changing boundary conditions and their compounding implications for building envelope performance.
Extensive experimental studies, measurement data, numerical calculations, and practical experienc... more Extensive experimental studies, measurement data, numerical calculations, and practical experience show that window ventilation supported by exhaust fans (i.e. mechanical extract ventilation) is a simple and highly effective measure to increase air quality in classrooms. This approach can be used against the aerosol transmission of SARS-CoV-2 (Helleis et al. 2021a; Lelieveld et al. 2020; Morawska et al. 2021). Mechanical extract ventilation (MEV) is very well suited not only for combating the COVID19 pandemic but also for sustainably ventilating schools in an energy-saving, resource-efficient, and climate-friendly manner (Helleis et al. 2021a, 2021b; Klimach and Helleis 2021) (www.ventilationmainz.de). The ventilation concept presented here is part of a multi-layered risk reduction strategy. As such it is not intended to replace, but rather to complement, other preventive public health measures - including vaccinations, masks and social distancing (Bodenschatz 2021; Cheng et al. 202...
Numerous studies have reported on overheating in urban contexts the majority of which have focuse... more Numerous studies have reported on overheating in urban contexts the majority of which have focused on the influences of external factors, such as: heat waves and climatic change. To date very little research has examined the more insidious issue of chronic year-round overheating in temperate climatic zones. The present study begins by reviewing the potential implications of planning and legislative constraints underlying urban residential design. A case study example is then introduced to examine the potential manifestation of such issues in practice. Detailed field monitoring and survey data from a number of newly built flats in a multi-residential block in London, is presented. Typical of a new generation of urban dwellings the development incorporates a high thermal specification together with low carbon building services, such as communal heating systems and mechanical ventilation with heat recovery. Through detailed zonal measurements of a broad range of environmental and building services parameters it has been possible to isolate the key factors underpinning poor overheating performance for these flats. The findings of this case study are part of a larger research project investigating the causes of overheating in high density urban dwellings across Greater London. The results suggest that the causes of chronic overheating in these modern low-energy flats are multiple, but typically share common factors stemming from poorly integrated architectural and MEP design decisions. Conflicts between regional planning policies, UK building regulations, and health and safety legislation appear to be compounding the problem.
According to the Passivhaus Institute (PHI) the verification of a Passivhaus design must be carri... more According to the Passivhaus Institute (PHI) the verification of a Passivhaus design must be carried out using the Passivhaus Planning Package (PHPP). A number of methods are now available for designers to access climatic data for use in PHPP design predictions. The original climate data provided for design and certification in the UK was derived from the reverse engineering of TRY data from dynamic simulations, for a limited number of locations. The following research examines the need for regional and, in some ...
The Welsh Assembly Government has implemented an "aspirational" target that from 2011 all new bui... more The Welsh Assembly Government has implemented an "aspirational" target that from 2011 all new buildings in Wales must be "zero carbon," five years ahead of the 2016 deadline originally set for homes in England. The PassivHaus concept developed in Germany has grown steadily in Europe demonstrating a reliable methodology for the design of ultra low energy buildings, therefore providing the possibility of an established method of meeting the zero carbon targets in Wales. Social housing projects currently being designed in Wales and Ireland using the PassivHaus Planning Package (PHPP) have highlighted challenges that may have strong implications for the design of future "zero carbon" dwellings in the UK and Irish maritime climates. This paper will discuss the above in more detail by showing the implications of applying the PassivHaus standard in Wales and examining the standard for its appropriateness in the supposedly milder Welsh climate. The research conducted will demonstrate that the PassivHaus concept offers a useful template but that it also implies uncertainty due to its thermal performance in the middle European maritime climatic zones with corresponding implications for design sensitivity.
The sensitivity of low energy and passive solar buildings to their climatic context creates a req... more The sensitivity of low energy and passive solar buildings to their climatic context creates a requirement for accurate local climate data. This situation takes on increasing importance in the context of modelling Passivhaus buildings where the absence of conventional oversized heating and cooling systems implies a greater reliance upon fabric and system optimisation. Conversely, future climatic changes may also pose serious implications for super insulated buildings with inadequate solar shading. Currently, many widely used building performance simulation (BPS) tools still rely on very limited sources of climate data. The following research examines the need for regional and, in some cases, micro-regional climatic data when designing ultra-low energy Passivhaus buildings in the UK. The paper proposes a new methodology for generating this data in PHPP format. The data generated is compared to alternative sources, and the implications discussed in the context of three case studies examining a certified Passivhaus dwelling in a mountainous region of Wales as well as two locations, in close proximity, within London. If correctly implemented the use of such data should provide a more robust basis for future cost and performance optimisation in low energy and passive building design.
In response to UK government policy mandating the construction of 'zero carbon' homes by 2016 the... more 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 ultralow 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 650 ppmv. Bows and Anderson (2008, p. 18) state that "given this analysis has not factored in a range of other issues with likely net positive impacts, adapting for estimated impacts of at least 4 _C appears wise." A 4 _C, average global temperature, increase by the end of this century is consistent with the Intergovernmental Panel on Climate Change (IPCC) best estimate for the A1FI trajectory, commonly known as the 'High' emission scenario, ((IPCC, 2007); Table 3.1). Reframing likely emissions in this light suggests that modelling the impacts of the A1FI scenario on the built environment can no longer be regarded as a cautionary approach. The risk of perverse consequences in the form of exacerbated overheating risks in super insulated Passivhaus dwellings have been highlighted in a number of
The energy consumption of buildings accounts for a significant amount of the total energy consume... more The energy consumption of buildings accounts for a significant amount of the total energy consumed by society. In the UK, domestic operational emissions currently accounts for over a quarter of the UK's total CO2 emissions (ONS, 2008). Despite increasingly tougher legislation for building fabric performance unregulated appliance and lighting emissions have continued to rise in the UK (Boardman et al, 2005). Low energy lighting systems have the potential to provide significant energy savings in the building ...
According to the Passivhaus Institute (PHI) the verification of a Passivhaus design must be carri... more According to the Passivhaus Institute (PHI) the verification of a Passivhaus design must be carried out using the Passivhaus Planning Package (PHPP). A number of methods are now available for designers to access climatic data for use in PHPP design predictions. The original climate data provided for design and certification in the UK was derived from the reverse engineering of TRY data from dynamic simulations, for a limited number of locations.
The process of building design is currently undergoing some major changes. In an attempt to mitig... more The process of building design is currently undergoing some major changes. In an attempt to mitigate climate change, the design of more sustainable building is advocated by the UK government. Furthermore, standalone design methods are being replaced with the concept of Building Information Modelling (BIM). The adoption of BIM has been documented to result in many benefits, which range from time to cost savings. During the initial planning stages, building performance simulation (BPS) can be used to inform design decisions. Data can be exchanged between BIM and BPS tools using data transfer schemas such as the Industry Foundation Classes (IFC). The IFC schema lacks an energy domain, and as a result, an extension is proposed in this paper. This contains energy concepts from a BPS tool called Passive House Planning Package (PHPP). The extended schema was developed by way of an externally coupled Java tool, which facilitates the transfer of data, and informs the building design decision-making process. The process of geometry extraction has been validated with several case studies, which are based on certified Passivhaus buildings in Hannover Kronsberg, Germany and Ebbw Vale, Wales. The amount of error is acceptable, and it is mostly due to differences in the initial BIM model set up, not due to the processing of IFC files.
Driven by Climate Change legislation and high rates of fuel poverty, the UK faces multiple challe... more Driven by Climate Change legislation and high rates of fuel poverty, the UK faces multiple challenges both in new build and upgrading the existing stock. How these challenges are addressed will have long term impacts on building fabric, occupant comfort and wellbeing. Building performance simulation has an important role to play in this process, yet it is widely recognised that oversimplification in the modelling of physical phenomena leads to substantial sources of error. Moisture is a major cause of damage in buildings, and the Glaser method is a widely used steady-state method used to calculate the vapour pressure difference in a building's envelope. Although known for its limitations, it is the principal method used to assess moisture response in the UK. This paper evaluates the current situation in the UK, addressing fuel poverty targets, energy saving regulations and changing boundary conditions and their compounding implications for building envelope performance.
Extensive experimental studies, measurement data, numerical calculations, and practical experienc... more Extensive experimental studies, measurement data, numerical calculations, and practical experience show that window ventilation supported by exhaust fans (i.e. mechanical extract ventilation) is a simple and highly effective measure to increase air quality in classrooms. This approach can be used against the aerosol transmission of SARS-CoV-2 (Helleis et al. 2021a; Lelieveld et al. 2020; Morawska et al. 2021). Mechanical extract ventilation (MEV) is very well suited not only for combating the COVID19 pandemic but also for sustainably ventilating schools in an energy-saving, resource-efficient, and climate-friendly manner (Helleis et al. 2021a, 2021b; Klimach and Helleis 2021) (www.ventilationmainz.de). The ventilation concept presented here is part of a multi-layered risk reduction strategy. As such it is not intended to replace, but rather to complement, other preventive public health measures - including vaccinations, masks and social distancing (Bodenschatz 2021; Cheng et al. 202...
Numerous studies have reported on overheating in urban contexts the majority of which have focuse... more Numerous studies have reported on overheating in urban contexts the majority of which have focused on the influences of external factors, such as: heat waves and climatic change. To date very little research has examined the more insidious issue of chronic year-round overheating in temperate climatic zones. The present study begins by reviewing the potential implications of planning and legislative constraints underlying urban residential design. A case study example is then introduced to examine the potential manifestation of such issues in practice. Detailed field monitoring and survey data from a number of newly built flats in a multi-residential block in London, is presented. Typical of a new generation of urban dwellings the development incorporates a high thermal specification together with low carbon building services, such as communal heating systems and mechanical ventilation with heat recovery. Through detailed zonal measurements of a broad range of environmental and building services parameters it has been possible to isolate the key factors underpinning poor overheating performance for these flats. The findings of this case study are part of a larger research project investigating the causes of overheating in high density urban dwellings across Greater London. The results suggest that the causes of chronic overheating in these modern low-energy flats are multiple, but typically share common factors stemming from poorly integrated architectural and MEP design decisions. Conflicts between regional planning policies, UK building regulations, and health and safety legislation appear to be compounding the problem.
According to the Passivhaus Institute (PHI) the verification of a Passivhaus design must be carri... more According to the Passivhaus Institute (PHI) the verification of a Passivhaus design must be carried out using the Passivhaus Planning Package (PHPP). A number of methods are now available for designers to access climatic data for use in PHPP design predictions. The original climate data provided for design and certification in the UK was derived from the reverse engineering of TRY data from dynamic simulations, for a limited number of locations. The following research examines the need for regional and, in some ...
The Welsh Assembly Government has implemented an "aspirational" target that from 2011 all new bui... more The Welsh Assembly Government has implemented an "aspirational" target that from 2011 all new buildings in Wales must be "zero carbon," five years ahead of the 2016 deadline originally set for homes in England. The PassivHaus concept developed in Germany has grown steadily in Europe demonstrating a reliable methodology for the design of ultra low energy buildings, therefore providing the possibility of an established method of meeting the zero carbon targets in Wales. Social housing projects currently being designed in Wales and Ireland using the PassivHaus Planning Package (PHPP) have highlighted challenges that may have strong implications for the design of future "zero carbon" dwellings in the UK and Irish maritime climates. This paper will discuss the above in more detail by showing the implications of applying the PassivHaus standard in Wales and examining the standard for its appropriateness in the supposedly milder Welsh climate. The research conducted will demonstrate that the PassivHaus concept offers a useful template but that it also implies uncertainty due to its thermal performance in the middle European maritime climatic zones with corresponding implications for design sensitivity.
The sensitivity of low energy and passive solar buildings to their climatic context creates a req... more The sensitivity of low energy and passive solar buildings to their climatic context creates a requirement for accurate local climate data. This situation takes on increasing importance in the context of modelling Passivhaus buildings where the absence of conventional oversized heating and cooling systems implies a greater reliance upon fabric and system optimisation. Conversely, future climatic changes may also pose serious implications for super insulated buildings with inadequate solar shading. Currently, many widely used building performance simulation (BPS) tools still rely on very limited sources of climate data. The following research examines the need for regional and, in some cases, micro-regional climatic data when designing ultra-low energy Passivhaus buildings in the UK. The paper proposes a new methodology for generating this data in PHPP format. The data generated is compared to alternative sources, and the implications discussed in the context of three case studies examining a certified Passivhaus dwelling in a mountainous region of Wales as well as two locations, in close proximity, within London. If correctly implemented the use of such data should provide a more robust basis for future cost and performance optimisation in low energy and passive building design.
In response to UK government policy mandating the construction of 'zero carbon' homes by 2016 the... more 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 ultralow 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 650 ppmv. Bows and Anderson (2008, p. 18) state that "given this analysis has not factored in a range of other issues with likely net positive impacts, adapting for estimated impacts of at least 4 _C appears wise." A 4 _C, average global temperature, increase by the end of this century is consistent with the Intergovernmental Panel on Climate Change (IPCC) best estimate for the A1FI trajectory, commonly known as the 'High' emission scenario, ((IPCC, 2007); Table 3.1). Reframing likely emissions in this light suggests that modelling the impacts of the A1FI scenario on the built environment can no longer be regarded as a cautionary approach. The risk of perverse consequences in the form of exacerbated overheating risks in super insulated Passivhaus dwellings have been highlighted in a number of
The energy consumption of buildings accounts for a significant amount of the total energy consume... more The energy consumption of buildings accounts for a significant amount of the total energy consumed by society. In the UK, domestic operational emissions currently accounts for over a quarter of the UK's total CO2 emissions (ONS, 2008). Despite increasingly tougher legislation for building fabric performance unregulated appliance and lighting emissions have continued to rise in the UK (Boardman et al, 2005). Low energy lighting systems have the potential to provide significant energy savings in the building ...
According to the Passivhaus Institute (PHI) the verification of a Passivhaus design must be carri... more According to the Passivhaus Institute (PHI) the verification of a Passivhaus design must be carried out using the Passivhaus Planning Package (PHPP). A number of methods are now available for designers to access climatic data for use in PHPP design predictions. The original climate data provided for design and certification in the UK was derived from the reverse engineering of TRY data from dynamic simulations, for a limited number of locations.
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Papers by Robert McLeod