BEIS Thin Internal Wall Insulation
Evaluating the performance of novel Internal Wall Insulation
This report presents the preliminary findings from before and after building performance evaluation (BPE) field trials undertaken to measure the impact of six TIWI and one conventional IWI retrofits. Their impact on thermal bridging and hygrothermal models identified how they affected moisture risk. Dynamic simulation models predicted the energy demand reductions to evaluate potential carbon and fuel bill savings. Coheating tests measured the reduction in the heat transfer coefficient (HTC) measured in W/K, which describes the holistic impact on the home’s heating demand. In addition, blower door tests and heat flux measurements quantified the difference that the retrofits had on infiltration (uncontrolled air leakage) and fabric heat loss, i.e. wall U-value measured in W/m²K, respectively. Appraisal of the installation costs and how the TIWI products could overcome installation barriers was undertaken, supported by surveys in 100 homes to identify insulation and dwelling characteristics that affected costs or risks, such as requirements to replace plumbing, boilers and radiators, apply decoration or repair damp walls.
Research outputs
This project is currently in progress, if you would like any more information, please contact us.
Preliminary findings report
DECC Core Cities Green Deal Monitoring Project - Leeds
Leeds was designated a core city for trialling the Government’s Green Deal domestic energy efficiency policy. Leeds Beckett University undertook a monitoring and testing programme on 65 dwellings to investigate the effectiveness of the insulation measures installed and to understand any underperformance. This report outlines the findings from a series of investigations including: surveys, air tightness tests, co heating tests, in situ U-value tests, hygrothermal and thermal bridging modelling, in-use monitoring and occupant interviews. The surveys revealed that the ‘whole house approach’ to retrofit was, more often, missing, and quality assurance around insulation detailing was regularly absent, leading to avoidable errors and potentially embedding problems in the installations. Furthermore, moisture issues were, in the majority of instances, over-looked or made worse despite over half the sample having some form of damp. Despite this, energy savings were observed and the appearance of the dwellings were improved, thus apparent satisfaction was generally high, even though the installs were imperfect and moisture problems were introduced.
Research outputs
- Gorse, C.A.,& Glew, D., Johnston, D., Fylan, F., Miles-Shenton, D., Smith, M., Brooke-Peat, M., Farmer, D., Stafford, A., Fletcher, M. and Thomas, F. (2017) Core cities Green Deal monitoring project – Leeds, 2017, Department of Energy and Climate Change.
- Fylan, F., Glew, D., Smith, M., Johnston, D., Brooke-Peat, M., Miles-Shenton, D., Fletcher, M., Aloise-Young, P. and Gorse C. (2016) Reflections on retrofits: Overcoming barriers to energy efficiency among the fuel poor in the UK, Energy Research and Social Science, 190-198
- Hardy A, Glew D, Gorse C, Fletcher M, (2018), Validating solid wall insulation retrofits with in-use data, Energy and Buildings, 165, 200-205
- Glew, D.W., Smith, M., Miles-Shenton, D. and Gorse, C. (2017) Assessing the quality of retrofits in solid wall dwellings, International Journal of Building Pathology and Adaptation, 35 (5), 501-518
Derwentside MVHR
Evaluating the success of MVHR retrofits
The aim of this project was to assess the effectiveness of the whole house mechanical ventilation and heat recovery (MVHR) systems within the existing UK housing stock. This was investigated via field trials into homes where MVHR was installed as part of a comprehensive energy efficiency and environmental improvement package. Evaluations were made in terms of energy use, thermal comfort, internal air quality and acceptability to tenants.
Research outputs
Green Homes Finance Accelerator
High Rise Heat Pump Pilot Scheme
The high-rise electric heating & hot water pilot project was a two-year project to compare an existing heating system (electric storage heaters) and a new, sustainable, ground source heat pump in high rise blocks in Leeds. Two case study high-rise blocks were selected for this project due to their construction type, energy efficiency rating and negative resident feedback. The Heights East and The Heights West are 10-storey, Townsen design blocks, and each contain 60 flats with an equal mix of 1 and 2 bedrooms. Electricity use, internal conditions and occupant experience were monitored over a 2-year period in 20 flats (10 flats per block) to provide insight into the way that occupants heat their homes and manage their energy use. Phase 1, covering the first year of monitoring, evaluated the existing heating system, with Phase 2 in the second year monitoring in the new system.
The project found substantial reduction in both energy use and carbon emissions following the change to a heat pump, despite the influence of Covid on home occupancy rates during Phase 2. The heat pump also received praise from occupants, who saw improvement in their thermal comfort and valued the additional control that the heat pump system gave them. The findings from this project had significant impact, and were central in influencing future low carbon policy and investment within Leeds City Council. The pilot blocks are typical of those in both local and national stock, many of which will require upgrade to their heating systems in the coming decade. This research provided evidence on the effectiveness of heat pumps as a possible alternative solution for heating in high-rise buildings.
Report findings
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.
Temple Avenue Project
BPE of Prototype Low Carbon Dwellings
The Temple Avenue Project, funded by the Joseph Rowntree Housing Trust, outlines the initial evaluation of the design, construction and performance of two prototype low carbon dwellings and helps establish the extent to which an existing 1930s masonry house can be renovated so as to achieve a level of performance commensurate with the advanced energy and carbon standard of the prototype new dwellings. The two prototype dwellings contained some technological innovation and were constructed between July and December 2009. One prototype was constructed using thin-joint masonry construction and another using a structural insulated panel (SIPs) build system. The concurrent renovation works to an adjacent existing dwelling explored the impact of two standards of renovation, one reflecting the standard fabric measures that are currently considered to be cost effective and one reflecting the more challenging requirements of an 80% emissions reduction and incurring greater capital costs.
Research outputs
WDH Retrofit