Airtightness of buildings
Achieving air tightness in practice
This Department of Communities and Local Government-funded project considered the overall conclusions and key messages obtained through design assessments, construction observations, discussions with developers and pressurisation test results. The project analysed the airtightness performance of current UK housing, the implementation and impact of current and future legislation and identified potential areas for future work. Following an initial literature review, the project adopted an action research methodology that involved the research team working very closely with five developers to investigate the practical design and construction issues that arise in making improvements to the airtightness of speculatively built mainstream housing. Two construction types were represented in the project, masonry cavity and steel frame. The project highlighted a number of issues that need to be considered when constructing dwellings to meet a particular airtightness target. Suggesting that certain construction types appear to be intrinsically more airtight than others, complexity of the design can have a significant effect on airtightness, certain approaches to improving airtightness are likely to be both more successful and more robust than others and that achieving consistently high levels of airtightness in dwellings may prove difficult within existing design and construction cultures.
Research outputs
Assessing Government Energy Price Cap with Smart-metre Data
Challenging the equity of UK Energy Price Caps
In 2017, the British Government imposed a cap on prepayment energy prices in an attempt to combat fuel poverty. The maximum amounts allowed in the price caps were based on national averages, which can ignore some of the finer detail in the data. In this work, we used smart-meter data to see if any demographics are not receiving the full benefit of the price caps. The findings suggest that many economy 7 customers are not behaving typically, and may find themselves still struggling under the current price caps.
Research outputs
- Hardy, A., Glew, D. and Gorse, C. (2018) Assessing the equity and effectiveness of the GB energy price caps using smart meter data, Energy Policy, 127, 179-185
CEN Technical Committee 89 Working Group 13 Task Group 5
Standardising how to measure the efficiency of buildings
Based upon our international reputation associated with undertaking electric coheating tests, Professor David Johnston was invited to become an expert member of the British Standards Institution B/540/9 and CEN Technical Committee 89 Working Group 13 Task Group 5. As part of his CEN Working Group role, he has been working with European colleagues to develop a new European (CEN) standard based upon the Whole House Heat Loss Test Method (Coheating) developed at Leeds Beckett University. The new standard is entitled 'Thermal insulation – Construction products, building elements and structures – In-situ measurement of thermal performance – Testing of completed buildings Part 1: Data Collection'.
Research outputs
For more information about this project please contact us.
Coheating Method for Whole House Heat Loss
The gold standard for measuring the Heat Transfer Coefficient in buildings
The electric 'co heating' test, which is in the process of being developed into an international CEN standard and has been used by other institutions (both in the UK and abroad) as the reference test for assessing the aggregate performance of the building fabric in both new and existing dwellings. The electric coheating test has also been used to validate other building fabric thermal performance methodologies and is forming the basis of future research into validating building fabric thermal performance through the use of smart meter data. A quasi-steady state test method undertaken on an unoccupied dwelling to quantify the Heat Transfer Coefficient (HTC) of the dwelling in W/K. Currently in the process of being converted into a CEN standard.
Research outputs
Read more about H21
Eurisol Cavity Party Wall Thermal Bypass
Cavity party wall thermal bypass investigations
This work was funded by Eurisol, the UK Mineral Wool Manufacturers Association. This project followed on from the Stamford Brook field trial, which identified significant heat losses via party wall cavities in terraced and semi-detached masonry houses, and proposed various techniques to eliminate or minimise the effect. The purpose of this study was to extend the work carried out at Stamford Brook, and help in the development of practical low-cost solutions to mitigate of heat loss via party wall cavities.
Research outputs
Fabric Insulation Project L1
Early investigations into the effectiveness of retrofits
The overall objective of this project was to define a coherent conceptual and analytical framework within which the technical requirements for the next three reviews of Part L can be debated and decided. The key objective of the project was to chart a possible course specifically for fabric performance out to 2013 and later. The L1 project was carried out for the ODPM Building Regulations Division under the Building Operational Performance Framework by the FMNectar consortium.
Research outputs
- LOWE, R.J. and WINGFIELD, J. (2005) Fabric Insulation – Ways of Further Raising Performance Standards for all Types of Building Fabric - Cost Effectiveness of Thermal Insulation – Costing and Evaluation, Report to ODPM
- LOWE, R.J. and WINGFIELD, J. (2004) Fabric Insulation – Ways of Further Raising Performance Standards for all Types of Building Fabric - Interim Report on Insulation Standards in Selected European Countries, Report to ODPM
- LOWE, R.J. and WINGFIELD, J. (2004) Fabric Insulation – Ways of Further Raising Performance Standards for all Types of Building Fabric - Final Report on Insulation Standards in Selected European Countries, Report to ODPM
- LOWE, R.J. (2004) Workshop on Task 1 deliverable - initial exploratory report on cost effectiveness of thermal insulation, Report to ODPM
- LOWE, R.J. (2004) Initial Exploratory Report on Cost Effectiveness of Thermal Insulation, Report to ODPM
InDEED - Investigating Domestic Energy Efficiency Data Analytics
Identifying errors in EPCs
Funding was provided by the Economic and Social Research Council via the Consumer Data Research Centre. Energy Performance Certificates (EPCs) give people an idea of how energy efficient their homes are, but EPCs are notoriously unreliable and full of errors. This project identifies EPCs which are likely incorrect allowing them to be removed from any analysis. The project found that a large number (up to 62%) of EPCs contain at least one major error, calling into question how useful they are as a measure of energy efficiency in their current form. Furthermore, the errors found in each region of the UK varies considerably, with London containing the most.
Research outputs
International Energy Agency Annex 58
Reliable building energy performance characterisation based on full-scale dynamic measurement
After building a strong reputation in building performance characterisation, the Centre for the Build Environment (CeBE) at Leeds Beckett University were invited to participate in the International Energy Agency Annex 58. The ultimate goal of the Annex is to develop the necessary knowledge, tools and networks to achieve reliable in situ dynamic testing and data analysis methods that can be used to characterise the actual energy performance of building components and whole buildings.
Research outputs
International Energy Agency Annex 67 - Energy Flexible Buildings
Investigating the potential for flexibility to solve energy problems of the future
Leeds Sustainability Institute's building performance group are taking a lead on the International Energy Institutes Annex 67 project, Energy Flexible Buildings project, with more than 20 participants from across Europe and further afield. The project has commenced its preparatory year, with substantial input from our university, looking into how buildings can contribute and interact with energy networks.
Research outputs
For more information about this project please contact us.
Leeds City Council Damp Monitoring
Identifying the causes of damp to protect vulnerable tenants and inform council interventions
As part of the project investigating the condition and damp issues in Leeds City Council-owned homes, Leeds Sustainability Institute at Leeds Beckett University were commissioned to undertake a series of quantitative and qualitative research exercises. These were: airtightness measurement of dwellings, thermographic survey of dwellings, occupant interviews, and analysis of in-use internal environment data. Overall, the airtightness of dwellings in the research sample is not a major concern when considering their age and material condition. The key consideration, however, is that the values presented are for uncontrolled air movement aggregated across the whole dwelling. It is likely that air exchange is not occurring in a consistent way, with some areas potentially over-ventilating (e.g. windows, gaps and cracks) and some under-ventilating (e.g. wet rooms). It is for this reason that it is necessary to undertake a thermographic survey alongside the airtightness test when the dwelling is depressurised. The thermal surveys identified several commonly occurring issues with the building fabric, which may contribute to the formation of damp and mould. One barrier to tenants taking preventative action was a lack of capability due to faulty or non-existent mechanical ventilation systems. Although aware of risk, occupants reported very little guidance for damp prevention, suggesting a lack of knowledge towards both the cause and prevention of damp. Damp prevention guidance may therefore be effective in reducing damp occurrence.
Research outputs
For more information about this project please contact us.
NPS Damp LCC
Local councils spend a substantial amount each year resolving issues arising from damp and disrepair in their social housing stock. To understand the causes of these issues, the LSI undertook a series of quantitative and qualitative research exercises in collaboration with NPS and Leeds City Council. These tests included: airtightness measurement of dwellings, thermographic surveys of dwellings, occupant interviews and analysis of in-use internal environment data. This series of tests were performed across a representative sample of 31 dwellings taken from a wider estate where issues with damp were higher than average.
The sample was selected to include dwellings both with reported damp issues and with no reported issues, so that data may support the identification and disaggregation of likely risk factors contributing to moisture related issues.
The project was instrumental in identifying commonly occurring fabric issues, including missing insulation, thermal bridging, faulty seals, and penetrating moisture. Engagement with the occupants also highlighted common behaviours that led to an enhanced risk of moisture issues, such as under ventilation and indoor clothes drying. Importantly, the research also explored the rationale behind such behaviours and the occupant perspectives on risk, responsibility and awareness when considering the links between moisture, damp, and mould. The findings were used by Leeds City Council to improve their strategy for retrofit and damp mitigation, including providing additional guidance to occupants on managing moisture in the home.
Retail Energy Management System
Identifying energy efficiency improvements in supermarkets
Energy use and management in supermarkets represents a challenge as well as an opportunity. Improvements have the potential to benefit companies and consumers, and to contribute to the achievement of UK carbon reduction targets. This research project has the aim of improving energy efficiency in supermarkets using data visualisation tools. Funding was provided by Innovate and partners were: ASDA, who provided the data and case studies, Cybula, who developed the software, REMS and the Leeds Sustainability Institute (LSI), based at Leeds Beckett University. The project identified that it is recommended that visualisation tools should only be used in stores where there is high confidence around the quality and quantity of available data and a data capture pro forma has been developed to inform this. Shop floor area is conventionally the preferred method of normalising energy data to rank store performance. This was found to be acceptable and other minor variables were discovered to be relatively unimportant. However, using volume to normalise gas and HVAC energy use, and using chilled floor area when normalising refrigeration energy provided the best normalisation. Two approaches were used to predict a store’s ‘normal’ performance. The first simply used data to determine the mathematical correlation between energy use and energy demand. This produced a somewhat useful model for gas use and refrigeration energy use that could be incorporated into a visualisation tool, though HVAC energy use displayed much weaker correlation. The second approach used calibrated simplified dynamic simulation models to create baseline models of stores to compare stores as well as assessing changes in energy caused by varying inputs such as same ceiling heights.
Research outputs
For more information about this project please contact us.
Technology Strategy Board Building Performance Evaluation Programme
Nationwide BPE investigations into Low Carbon Homes
In 2011, the Technology Strategy Board (now Innovate UK) launched the £8million Building Performance Evaluation (BPE) Programme. An overarching aim of the BPE programme was to assemble comparable data and knowledge about a large number of buildings to enable analysis across the body of case study information, leading to generic findings conclusions and learning for the sector as a whole. As part of this Programme, the Centre for the Built Environment (CeBE) were successful in securing over £500,000 of external funding to undertake six post construction and early occupation studies (25% of all of the domestic projects awarded under the Technology Strategy Board BPE Programme) and two in-use performance and post occupancy evaluation studies. Additionally, all participants involved in the wider BPEP were required to adhere to standardised BPE practices based on the Leeds Beckett University Coheating Text Protocol.
Research outputs
- Gentoo Passivhaus Racecourse Development, Sunderland
Type of study – Post construction and early occupation.
- Gentoo Passivhaus Racecourse Development
Type of study – In-use performance and post occupancy evaluation.
- Dormary Court, York
Type of study – Post construction and early occupation.
- Dormary Court, York
Type of study – In-use performance and post occupancy evaluation.
- Lancaster Cohousing Development, Lancaster
Type of study – Post construction and early occupation.
- Community in a Cube (CIAC), Riverside One, Middlesborough
Type of study – Post construction and early occupation.
- Derwenthorpe, York
Type of study – Post construction and early occupation.
- Lea Field Court, York
Type of study – Post construction and early occupation.
- Fletcher MJ; Johnston DK; Glew D; Parker J (2017), An empirical evaluation of temporal overheating in an assisted living Passivhaus dwelling in the UK. Building and Environment, 121, Pages 106-118
https://doi.org/10.1016/j.buildenv.2017.05.024
- JOHNSTON, D. and SIDDALL, M. (2016) The Building Fabric Thermal Performance of Passivhaus Dwellings—Does It Do What it Says on the Tin? Sustainability, 8(1), 97; DOI:10.3390/su8010097.
- JOHNSTON, D. and STAFFORD, A. (2016) Estimating the Background Ventilation Rates in New-Build UK Dwellings – is n50/20 appropriate? Indoor and Built Environment. Published online before print January 28, 2016, DOI: 10.1177/1420326X15626234.
- JOHNSTON, D. MILES-SHENTON, D.FARMER, D. and BROOKE-PEAT, M. (2015) Post Construction Thermal Testing: Some Recent Measurements. Engineering Sustainability. Volume 168, Issue 3, June 2015, pp. 131-139. DOI: 10.1680/ensu.14.00048.
- JOHNSTON, D. MILES-SHENTON, D. and FARMER, D. (2015) Quantifying the Domestic Building Fabric ‘Performance Gap’. Building Services Engineering Research & Technology (BSER&T). Volume 36, No.5, September 2015, pp.614–627. DOI:10.1177/014362441557034.
- JOHNSTON, D. FARMER, D. BROOKE-PEAT, M. and MILES-SHENTON, D. (2014) Bridging the Domestic Building Fabric Performance Gap. Building Research & Information. Volume 44, Issue 2, pp.147-159. DOI:10.1080/09613218.2014.979093.
Wakefield District Homes Thermographic Surveys
Evaluating airtightness in BISF and solid brick social housing
Wakefield District Housing (WDH) commissioned the Leeds Sustainability Institute (LSI) at Leeds Beckett University to undertake pressurisation tests and thermographic surveys on 20 semi-detached dwellings. The results showed that there was no noticeable improvement in the airtightness of dwellings that had EWI compared to those without EWI in either BISF or solid walled dwellings. A larger sample size of BISF homes without EWI and both solid walled properties with and without EWI would be needed to assess if this finding was statistically significant. CO2 decay analysis was used in an attempt to validate the blower door results, however, the results were inconclusive due to a low sample size and uncontrolled conditions due to occupant activity. Improving air tightness is not the main function of EWI and this has been sustained by our findings. The results confirm that the fabric performance benefit of EWI is restricted almost exclusively to improving wall U-values, i.e. reducing heat loss through the fabric, not affecting heat loss through uncontrolled ventilation in the dwellings.
Research outputs
For more information about this project please contact us.