The official launch of RdSAP 10 is just around the corner and the 15th June is fast approaching! Whether you’ve already started preparing or need a quick refresher, now is the time to make sure you’re fully up to speed with the upcoming changes. From expanded ventilation options and detailed window measurements to the inclusion of air pressure test results, RdSAP 10 represents the biggest shift in assessment methodology in years.

Summary of Key Changes

Below you can find a high-level summary of the key updates to the methodology for RdSAP 10. This list is by no means extensive but if you’re an Elmhurst member, you have access to a whole range of resources to help you with the update, including:

• Detailed Technical Bulletins
• Assessment forms
• Evidence Collection Walkthrough Videos
• Software Update Videos and more.

Find all available resources included within your Elmhurst membership here >

Room in the Roof

Assessors can now choose between two distinct Room in Roof types, and for each, must specify whether the assessment will follow a simplified or detailed method. These changes require additional measurements, including dimensions of gable and where necessary common walls, to accurately reflect differing construction types. The aim is to improve the precision of energy assessments by capturing the unique characteristics and thermal performance of these spaces.

Elmhurst members have access to a full technical bulletin covering all the Room in the Roof Changes for RdSAP 10 which you can view here >

Windows

In one of the biggest changes for assessors, all windows must now be measured for an RdSAP 10 assessments. Additional options will also be available, such as frame types and permanent shutters, and the glazing age categories have been expanded to better align with regional standards and installation dates.

Ventilation (including Air Pressure Test Results)

Ventilation options have been extensively expanded for RdSAP 10 to include multiple new options as well as increased data collection required. This includes options such as open fireplaces, chimneys and flues to name a few. Mechanical ventilation systems are now much better supported with increased input options.

Air Pressure test Results

As part of RdSAP 10, air pressure test results can now be included where documentary evidence is available. By including measured air pressure test results, it provides the opportunity for a building’s performance to be more accurately recorded within the assessment, offering a better representation of its energy efficiency.

If you are not already offering air pressure testing, it’s a great time to think about adding this service to your offering and including in your RdSAP 10 assessments. Find out more about air pressure testing here >

Walls, Roof and Floors

RdSAP10 introduces enhanced options for walls, roofs, and floors to improve the overall accuracy of the assessment. Assessors can now specify two alternative wall types per building part and wall insulation options are more detailed, allowing for the recording of actual thicknesses and, where evidence is available, thermal conductivity values.

For roofs, a broader range of insulation thicknesses is now available, and a new option has been added to account for non-residential or unheated spaces above, such as commercial units above flats. Similarly, retrofitted floor insulation can now be recorded with precise thickness options.

Other Notable Updates

• Lighting: The number of bulbs must now be collected, not just the number of fittings, and it should be identified how may are LEDs or CFLs.
• New technologies: PV battery storage, diverters, and even small-scale hydro generation are now recognised.
• Water Heating: Cylinder size can now be accounted for. Heat loss can also be accounted for if documentary evidence is available.
• Heated Basements: More detail included and additional construction options to choose from, with specific u-values applied to walls and floors to better represent the space.

A step towards a greener future

The confirmed rollout of RdSAP 10 marks a significant milestone in the UK’s journey towards a more energy-efficient and sustainable housing stock. As regulations tighten and the drive to achieve net zero continues, accurate energy assessments are becoming more important than ever. They not only influence property values but also define the responsibilities of homeowners and landlords in achieving minimum energy performance standards.

With its expanded scope and improved data inputs, RdSAP 10 better reflects modern technologies, low-carbon initiatives and the diversity of the UK’s buildings. It offers a more realistic picture of a home’s performance, with smarter recommendations, allowing more effective retrofit decisions to be made.

Elmhurst is committed to supporting its members throughout the transition with a full collection of resources including technical bulletins, update videos and software walkthroughs. See all the available resources here >