Energiesprong UK has published their first performance report
With spiralling energy costs and unprecedented heatwaves, rapid scale up of retrofit has never been more urgent. As an industry we must come together and share learning if this is to be successful. We’re therefore excited that Energiesprong UK has published their first performance report – detailing performance data from our Nottingham City Homes 2050 project alongside five other UK social housing schemes.
The report includes highlights and honest learning from the experience of delivering deep retrofit. It finds:
Properties retrofitted using the Energiesprong model do, on average, meet their targets (particularly regarding fabric efficiency) 71% of properties had a measured fabric thermal performance within +15% of the design value.
Energiesprong properties (even those with high consumption) are having a massively reduced impact on the grid compared to local homes – 70%+ less energy on average.
PV should be maximised on every project (it typically represents best value for money!)
Heat pump performance needs to be better understood and improved upon.
Some like it hot! Retrofitted homes have the potential to massively improve health and wellbeing for residents but should our expectations of winter comfort change?
We need to collect more resident feedback to complement these energy performance findings. Energiesprong UK have a detailed survey in action now. While even the resident using most energy is still using 43% less than similar homes in the same area, it is still essential to understand why there is such a variation.
Metering and monitoring systems need a bit more work
a. Immersion heaters should be sub-metered as part of the energy services rather than resident appliances
b. Data communications from monitoring systems is often poor and needs improving
c. Monitoring needs to be automated better and outputs standardised across projects
More work is needed to identify whether the range of results for most metrics are down to the users or due to the solution operation/efficiency/thermal performance etc.
Comparing design and reality can be tricky with some of the Energiesprong metrics (in particular space heating kWh/m2/yr). Energiesprong UK are improving the methods to do this i.e., using pro formas, encouraging Heat Transfer Coefficient (HTC) measurement and airtightness testing etc. Energiesprong UK are also reviewing our performance spec to account for this complexity
The combination of fabric insulation + solar PV + heat pumps is relatively well established now as the main approach for these deep retrofits. But, we must ensure that we as an industry allow innovation to continually flourish.
To access the performance report, please click on the title hyperlink: Energiesprong UK performance overview 2021/2022.
