SAP/ SBEM Energy Assessments
SAPs and SBEMs are most effectively done at three stages – Draft, Design and Final.
The most important stage is the Draft stage, because a return to Planning due to high Renewables costs or Part L failure would be disproportionately expensive. A Building Regulations failure should automatically trigger advice from the Energy Assessor on how to comply with Part L1A of Building Regulations, as well as any other requirements, such as BREEAM. Compliance will include a number of aspects:
- Proposed CO2 Emissions (kg CO2 /m2/yr);
- Design Limits – Worst acceptable U-values; Heating efficiencies consistent with DHCG; HWC consistent with DHCG; Fixed internal and external lighting compliance;
- Overheating Risk;
- Construction Quality – Key design features included as built; Air permeability standard (based on pressure test certificates carried out by an accredited pressure tester) achieves the rate stated at the Design Stage.
For very high levels of energy efficiency thermal bridging analysis, using specialist software, is strongly recommended. This examines and advises upon a truly consistent level of continuous insulation all round outside of the building – the thermal envelope.