Existing Homes Guidance Note

NatHERS for existing homes Guidance Note.  This document supports assessors to navigate the assessment process. It outlines mandatory and recommended steps, offering general guidance to assessors undertaking an existing homes assessment. The NatHERS for existing homes Guidance Note supports the NatHERS for existing homes Technical Note.

NatHERS Existing Homes Guidance Note, 29 October 2025 - Current

This is the latest version of the Existing Homes Guidance Note and should be used until further notice. 

NatHERS Existing Homes Guidance Note, 11 June 2025 (pdf) - Superseded

This version has now been superseded, please use the current version for all future work.