Why have my heat losses changed since the last time I opened the project?

We occasionally have to make small updates to how heat losses are calculated.

Autumn 2026: we are updating the default temperatures of heated and unheated spaces in line with new guidance. These updates will automatically be applied to heat loss calculations on new projects. On pre-existing projects, you will have the option to accept the new heat loss calculations, or to view the existing project as it was.