The next domestic energy efficiency scheme is most likely to use deemed scores instead of SAP/RdSAP for carbon and cost saving calculations. Deemed scores have been used in previous energy efficiency schemes. The method is considerably straightforward and is likely to deliver saving of time and cost, but not necessarily accuracy or transparency.

So far, domestic energy efficiency schemes have set the targets in terms of reduction in carbon emissions and cost of heating. This approach might have been adopted to match the scheme goals with the carbon budgets and targets established under the Climate Change Act 2008. Another reason could be to showcase compliance with Article 7 of the Energy Efficiency Directive.

Deemed scores as well as SAP/RdSAP provide only notional savings. Since the savings influence price of a measure, one has all incentives to manipulate the scoring method to get higher savings. Despite inaccuracy, the amount of resources invested in calculating and verifying notional savings are huge. DECC can significantly reduce a scheme’s administration and delivery costs by moving away from setting targets in terms of carbon/cost savings. A more realistic approach would be to have a scheme designed to install specific number of energy efficiency measures similar to the solid wall insulation minimum threshold under ECO.

Prior knowledge of number and types of measures to be installed will help obligated suppliers and other stakeholders to plan their work better. It will also reduce the Scheme Administrator’s evidence and audit requirements for score verification. Since the cost of delivery will not be depending on the amount of carbon/cost saved, there will be no incentive for manipulating the size or type of the property. It will also eliminate the need for any score uplifts as a lower target can be set for more expensive measures, like solid wall insulation.

To meet its reporting obligations, DECC can undertake in-house calculations of notional carbon/cost savings based on information submitted by obligated suppliers for each installation. This approach may not be free from limitations, but it is certainly more transparent and cost effective