Accurate assessment of both surface and interstitial condensation risk at the design stage of bui... more Accurate assessment of both surface and interstitial condensation risk at the design stage of buildings is of great importance - not just to minimise the damaging effects moisture can cause to building envelopes, but also to contribute to the provision of adequate indoor air quality. Guidance certainly does exist with regards to limiting thermal bridging in order to prevent condensation occurring on new constructions. However, a recent study has provided clear evidence that the reality, both in translating the available guidance into a specific design and in construction on site is often rather different from the ‘ideal’. This paper reports on that study and compares and evaluates the hygrothermal performance of construction details for different phases during the building life cycle. The results of both the surface and interstitial condensation risk simulations under both steady-state and transient conditions are presented and discussed. Significant differences in the hygrothermal ...
In the UK, there is mounting evidence that the measured in situ performance of the building fabri... more In the UK, there is mounting evidence that the measured in situ performance of the building fabric in new build dwellings can be greater than that predicted, resulting in a significant building fabric ‘performance gap’. This paper presents the coheating test results from 25 new build dwellings built to Part L1A 2006 or better. Whilst the total number of dwellings reported here is small, the results suggest that a substantial ‘performance gap’ can exist between the predicted and measured performance of the building fabric, with the measured whole building U-value being just over 1.6 times greater than that predicted. This is likely to have significant implications in terms of the energy use and CO2 emissions attributable to these dwellings in-use. Practical application This paper describes an aggregate approach (coheating test) that has been applied to a small sample of dwellings to quantify the size of the ‘performance gap’. The results suggest that this ‘gap’ can be large (> 100...
From the limited information that exists on the thermal performance of dwellings there is growing... more From the limited information that exists on the thermal performance of dwellings there is growing evidence of a significant gap between that which is predicted and the built product. Such differences between the intended and actual measured performance are not accepted nor tolerated in other industries. The differences in the performance can be considerable, with some buildings experiencing deviation from designed thermal transmittance resulting in twice the heat loss expected. This does not bode well for the industry when new dwellings are expected to achieve zero carbon standards by 2016. Although some of the problems are related to inadequate design, many are attributable to construction processes. Using the technical reports and feedback from researchers engaged in forensic investigations of building performance, this paper presents some general observations and some re-occurring problems associated with the management of the construction process. Specific areas of concern inclu...
For domestic buildings to meet current definitions of zero carbon the building fabric and service... more For domestic buildings to meet current definitions of zero carbon the building fabric and services must achieve 70% reduction in energy use, taking the carbon emissions down to less than 7 Kg CO2/m2. However, there is a significant obstacle to such endeavours. The ...
Building Services Engineering Research and Technology
It is estimated that in the UK, 200,000 residents live in park and holiday homes all year round, ... more It is estimated that in the UK, 200,000 residents live in park and holiday homes all year round, the majority of which are elderly and on low incomes. As these homes are often thermally inefficient and leaky, these residents are some of the most susceptible in society to fuel poverty. Despite this, there is a dearth of empirical data available on the in situ fabric performance of these homes. This paper presents the results obtained from undertaking a series of pressurisation tests and leakage identification on new build holiday homes. While the sample size reported is small, the results indicate almost a factor of two variation in the airtightness performance of the homes. In spite of this, all of the homes achieved an air permeability significantly lower than the default value incorporated within the industry standard Energy Efficiency Rating Calculator, suggesting that a much lower figure may be more appropriate. The results also suggest that the use of the air permeability metri...
International Journal of Building Pathology and Adaptation
Purpose The purpose of this paper is to provide a detailed appraisal of the quality of domestic r... more Purpose The purpose of this paper is to provide a detailed appraisal of the quality of domestic retrofits. Design/methodology/approach This paper presents the results of technical surveys on 51 retrofits undertaken before, during and after the retrofits. Findings Failures are observed to be endemic and characterised into five themes: 72 per cent showed moisture issues pre-retrofit, 68 per cent had moisture risks post-retrofit, 62 per cent did not adopt a whole house approach, 16 per cent showed inadequate quality assurance protocols and 64 per cent showed evidence of insufficient design detailing. Each theme is further subcategorised with a view to identifying implications for future policy. Research limitations/implications The findings suggest the 10 per cent Ofgem retrofit failure rates predictions are an underestimate and so there may be a need for additional investigations to understand the trend across the UK. Practical implications Recommendations to reduce the failure rates ...
Accurate assessment of both surface and interstitial condensation risk at the design stage of bui... more Accurate assessment of both surface and interstitial condensation risk at the design stage of buildings is of great importance - not just to minimise the damaging effects moisture can cause to building envelopes, but also to contribute to the provision of adequate indoor air quality. Guidance certainly does exist with regards to limiting thermal bridging in order to prevent condensation occurring on new constructions. However, a recent study has provided clear evidence that the reality, both in translating the available guidance into a specific design and in construction on site is often rather different from the ‘ideal’. This paper reports on that study and compares and evaluates the hygrothermal performance of construction details for different phases during the building life cycle. The results of both the surface and interstitial condensation risk simulations under both steady-state and transient conditions are presented and discussed. Significant differences in the hygrothermal ...
In the UK, there is mounting evidence that the measured in situ performance of the building fabri... more In the UK, there is mounting evidence that the measured in situ performance of the building fabric in new build dwellings can be greater than that predicted, resulting in a significant building fabric ‘performance gap’. This paper presents the coheating test results from 25 new build dwellings built to Part L1A 2006 or better. Whilst the total number of dwellings reported here is small, the results suggest that a substantial ‘performance gap’ can exist between the predicted and measured performance of the building fabric, with the measured whole building U-value being just over 1.6 times greater than that predicted. This is likely to have significant implications in terms of the energy use and CO2 emissions attributable to these dwellings in-use. Practical application This paper describes an aggregate approach (coheating test) that has been applied to a small sample of dwellings to quantify the size of the ‘performance gap’. The results suggest that this ‘gap’ can be large (> 100...
From the limited information that exists on the thermal performance of dwellings there is growing... more From the limited information that exists on the thermal performance of dwellings there is growing evidence of a significant gap between that which is predicted and the built product. Such differences between the intended and actual measured performance are not accepted nor tolerated in other industries. The differences in the performance can be considerable, with some buildings experiencing deviation from designed thermal transmittance resulting in twice the heat loss expected. This does not bode well for the industry when new dwellings are expected to achieve zero carbon standards by 2016. Although some of the problems are related to inadequate design, many are attributable to construction processes. Using the technical reports and feedback from researchers engaged in forensic investigations of building performance, this paper presents some general observations and some re-occurring problems associated with the management of the construction process. Specific areas of concern inclu...
For domestic buildings to meet current definitions of zero carbon the building fabric and service... more For domestic buildings to meet current definitions of zero carbon the building fabric and services must achieve 70% reduction in energy use, taking the carbon emissions down to less than 7 Kg CO2/m2. However, there is a significant obstacle to such endeavours. The ...
Building Services Engineering Research and Technology
It is estimated that in the UK, 200,000 residents live in park and holiday homes all year round, ... more It is estimated that in the UK, 200,000 residents live in park and holiday homes all year round, the majority of which are elderly and on low incomes. As these homes are often thermally inefficient and leaky, these residents are some of the most susceptible in society to fuel poverty. Despite this, there is a dearth of empirical data available on the in situ fabric performance of these homes. This paper presents the results obtained from undertaking a series of pressurisation tests and leakage identification on new build holiday homes. While the sample size reported is small, the results indicate almost a factor of two variation in the airtightness performance of the homes. In spite of this, all of the homes achieved an air permeability significantly lower than the default value incorporated within the industry standard Energy Efficiency Rating Calculator, suggesting that a much lower figure may be more appropriate. The results also suggest that the use of the air permeability metri...
International Journal of Building Pathology and Adaptation
Purpose The purpose of this paper is to provide a detailed appraisal of the quality of domestic r... more Purpose The purpose of this paper is to provide a detailed appraisal of the quality of domestic retrofits. Design/methodology/approach This paper presents the results of technical surveys on 51 retrofits undertaken before, during and after the retrofits. Findings Failures are observed to be endemic and characterised into five themes: 72 per cent showed moisture issues pre-retrofit, 68 per cent had moisture risks post-retrofit, 62 per cent did not adopt a whole house approach, 16 per cent showed inadequate quality assurance protocols and 64 per cent showed evidence of insufficient design detailing. Each theme is further subcategorised with a view to identifying implications for future policy. Research limitations/implications The findings suggest the 10 per cent Ofgem retrofit failure rates predictions are an underestimate and so there may be a need for additional investigations to understand the trend across the UK. Practical implications Recommendations to reduce the failure rates ...
Uploads
Papers by Dominic Miles-Shenton