Understanding Room in the Roof for RdSAP 10 Assessments

A Room in the Roof (RiR) is a space built into the roof of a property – typically a converted loft with sloped ceilings, dormer windows and accessed by a fixed staircase. These spaces are common in UK homes, especially in older housing stock, but they’ve long been a grey area in energy assessments.

How has RdSAP 10 changed inputs for Room in the Roof?

Under RdSAP 9.94, assessors had limited options for recording RiR details, often relying on default assumptions about insulation and construction. RdSAP 10 introduces a more detailed approach that includes:

• Separate entries for different types of Room-in-Roof
• Detailed insulation recording – Including slopes, stud, common wall, ceiling insulation, and gable walls.
• Window-by-window data – Each RiR window must be measured and recorded individually.
• Wall type identification – Gable, stud and slope walls distinguished and assessed separately.
• Photographic evidence – Required to support insulation claims and window types.

What does this mean for Domestic Energy Assessors?

For Domestic Energy Assessors, these updates mean you’ll now be required to capture more detailed information on Room in the Roof than before. Where possible, supporting evidence, such as documentation on wall insulation, should also be provided. The upgraded RdSAP software has been designed to accommodate all of these additional inputs.

With RdSAP 10, changes such as the inclusion of measured airtightness tests and expanded data entry fields ensure that your assessments will more accurately reflect the true performance of a property. This not only improves the accuracy of the Energy Performance Certificate but also ensures the recommendations provided on the certificate are more relevant.

Elmhurst Members have access to a full suite of RdSAP 10 resources to support them, including Technical Bulletins on Room in the Roof. View the resources here >

What do homeowners need to know if they are having an EPC assessment completed?

As a homeowner, if your home includes a loft conversion or attic room it may mean that your EPC assessment may take longer than expected. Assessors will need access to the RiR space, including behind eaves and insulation panels. You may also be asked more questions, including providing any evidence, such as building control documents, insulation specifications or renovation dates – it’s good to have this prepared in advance.

Most importantly you will have an EPC that better reflects your property and can offer more relevant recommendations for improvement.