Building energy performance: use of EPC data to illustrate performance of new homes: FOI release

FOI reference: FOI/18/03375
Date received: 6 November 2018
Date responded: 28 November 2018

 

 

You asked for information held by the Scottish Government on: work carried out in the past 5 years on “the performance gap” in new building dwellings and any analysis planned or budgeted for; publications and reports issued by Scottish Government use SAP/EPC data for new dwellings to indicate energy performance of new dwelling; and work done to verify that the performance quoted is being achieved.

 

Response

You posed four questions. A response to each is provided below.

1). What information and/or analysis carried out in the past 5 years is the Scottish Government in possession of, or is aware of that would help the SG to understand “the performance gap” in new building dwellings, i.e. how much energy is used by new dwellings compared to what is in the design energy use value?

No analysis of this type was undertaken by, or on behalf of The Scottish Government during the period specified.

2). If as before (per FoI/18/02895) the answer is none, is any analysis planned or budgeted for?

Such analysis is currently proposed as part of review of regulations.  Our call for evidence on review of energy standards within building regulations, which closed earlier this year, is published together with consultation responses on the Scottish Government website.  The consultation paper includes, within ‘Part 2 – Proposed scope of the review of energy standards’ a statement that the draft scope of review topics includes:

“Designed versus as-built performance – review on potential for action within the building standards system to improve the quality and performance of new buildings, including a comparison to their designed (calculated) performance”.

Further information on this and other topics will be published as the review of energy standards is progressed.

3). What publications and reports issued by Scottish Government use SAP/EPC data for new dwellings to indicate energy performance of new dwellings? E.g. I’ve seen an improvement in EPC rating used as an indicator that energy efficiency is improving in new dwellings in Scotland. 

Our ‘Energy in Scotland 2018’ publication discusses domestic energy efficiency and EPC ratings on pages 36-38 of Chapter 2. The information is taken from Scottish House Condition Survey published data, no additional analysis is carried out. This can be found at https://www2.gov.scot/Resource/0054/00541605.pdf.

The Scottish Government also publish a domestic EPC dataset.  This is available at: https://statistics.gov.scot/resource?uri=http%3A%2F%2Fstatistics.gov.scot%2Fdata%2Fdomestic-energy-performance-certificates

This dataset includes records for new homes assessed using the SAP methodology.

4). What work has been done to verify that the performance quoted is being achieved, or is it solely based on theoretical EPC/SAP data?

The performance quoted is solely based on theoretical EPC/SAP data.  The rationale underpinning the SAP assessment is set out in the Standard Assessment Procedure document, published by the Building Research Establishment on behalf of the UK Government. This is available at: https://www.bre.co.uk/filelibrary/SAP/2012/SAP-2012_9-92.pdf.