The introduction of legal requirements and regulations associated with Decent Homes, fuel poverty, Warm Homes and energy conservation has created a clear demand for effective ways to measure the energy efficiency of domestic properties. Since the 1990s, the Standard Assessment Procedure (SAP) has offered a way to estimate the energy performance of a property. In 2005, social housing providers were obliged to adopt the SAP for their stock and submit regular progress reports; the system also underpinned the calculations for Energy Performance Certificates. Although SAP ratings are collected by Registered Social Landlords (RSLs), greater accuracy is needed to meet future reporting requirements, and there is no clear model of how to optimally use the SAP to undertake exercises at the level of an individual property. Standardised guidance on how this could work in practice would be a valuable mechanism for the sector because it would allow social landlords to identify where resources should be focused and allow them to measure the impact of their interventions.
Key research Question
The aim of the report was to propose a standard mechanism that would allow RSLs to use the SAP data they already collected as a basis for more precise calculations of the proportion of their stock that did not meet the required levels of energy efficiency performance.
Summary of activity
The project built on the work described in the Energy Audit Company’s article ‘SAP Targets and Affordability’ (Energy Action, Issue No. 96, July 2005) and arrived at a simple easy-to-use tool that aims to help social housing providers in England and Wales identify homes that are energy-inefficient and set targets for their improvement to ensure that all homes are capable of delivering affordable energy. It examined information currently available to housing professionals, including its accuracy, and considered how SAP targets can be set that allow for rising fuel prices.
As part of the development of the tool, a structured questionnaire was sent to all Home Energy Conservation Act officers in England and Wales to collect baseline information on their housing stock and the SAP data they recorded.
The report proposes a model underpinned by several core principles. In terms of defining households’ energy ‘affordability’ – that is, the energy costs required to maintain acceptable levels of warmth – it advises that the basic income definition for fuel poverty be used and running costs should be linked to the SAP rating of the individual property. It suggests targets for affordability based on basic minimum income levels of vulnerable households and proposes a series of minimum and recommended SAP-based affordability targets. Practical suggestions on how to develop more refined measurements at the level of individual properties are discussed.
RSLs should establish SAP targets for all housing but introduce higher objectives for properties designed for the over-60s. These should be incorporated into Affordable Warmth strategies. Annual reporting should be adopted, and targets should be adjusted to reflect external factors such as fuel price changes.
The UK government should mandate SAP-based energy efficiency targets as part of Decent Homes guidance, although these should reflect regional differences. Reporting requirements should ask RSLs not only to detail the average SAP rating of their housing stock but also to include the proportion of properties that fall beneath the minimum level.
The government should also consider the option of compensating low-income households, potentially with fuel vouchers, to mitigate the impact of rising energy costs.