A long time coming
Our governing body on domestic energy assessments has released news on long overdue updates to the way domestic energy assessments are carried out [1]. There are loads of rumours about when these changes come into force but no hard facts yet. In the meantime, we’ve listed the expected changes with a few comments below.
Ready for the future
The current version of rdSAP doesn’t take into account many of the technological advances that have happened since its original launch. Here’s a few expected updates that we think will make the assessments ready for the future:
- Assessors will be able to take account of PV diverters that divert energy from solar arrays to hot water storage. PV diverters have been around for ages and many homes have them. We’ve long advised clients not to remove hot water storage cylinders so this will be an extra benefit of keeping them in.
- Batteries will also now be included, and assessors will be required to collect details – so please keep details of battery capacity. And proof/certification of existence at the address.
- A new age band will be included to take account of changes to new build standards since 2023, particularly on insulation. Keep details of build dates!
- Heat pumps will be recommended more. Despite heat pumps being a likely technology of the future it hardly ever gets recommended in the current version. Under certain conditions these will now be recommended more. The EPC rating will still be based on the modelled running cost of the home, so we’d expect heat pumps to be recommended only when running costs will be reduced. For example, in our experience these will be in homes with lpg or oil boilers.
- MVHR systems – mechanical ventilation with heat recovery – this technology recycles waste heat and uses it for space heating and can be highly efficient. You’ll have to keep details of PCDF reference and duct type and placement.
- Hydro and wind – less common but a little part of the future in the right place.
- Waste water heat recovery – these simple installations recycle heat from waste water and improve the efficiency of hot water supply. Please keep details if you have them installed!
Tweaks for accuracy
The following changes add a little more accuracy to the methodology:
- More window measurement – at the moment assessors make a judgement on whether the amount of glazing is more than normal, less than normal or about normal. The software does the rest. The new regime will mean actual measurement of each of the openings.
- More measurements are required for rooms in roofs.
- If any air pressure testing has been carried out this detail can be included provided it is correctly certified.
- There are some tweaks on the accuracy of communal heating – we’ll see how these pan out, but we know from looking at actual kWh for apartments that they are typically far less efficient than modelled.
So what?
There are two big implications for these changes. Firstly, due to the increased complexity and extent of the assessments, assessors are going to have to spend more time on site which means costs are likely to increase.
Secondly, to get the best out of the assessment, storing of actual data about the home, particularly new builds [2], is going to have increased importance.
If you would like rdSAP assessment work done to help you decide on the best way to net zero for your properties please take a look at our EPC consultancy and assessment services [3] and/or be in touch: [email protected]
[2] https://shiftenvironment.co.uk/news/data-to-transfer-from-new-build-department-to-asset-management/
[3] https://shiftenvironment.co.uk/news/domestic-energy-assessor-epc-rdsap/
Photo by Centre for Ageing Better: https://www.pexels.com/photo/solar-pannels-on-roof-of-old-building-9729882/