Part O overheating guidance

Simplified assessment or TM59?

Answer a few straightforward questions about the dwelling, windows and site constraints to see which overheating assessment route appears most appropriate.

Start the route finder ↓ Back to tools

✓Free initial guidance

✓About three minutes

✓For new homes in England

Overheating route finder

Tell us about the project

Select the closest answer. You can go back and change any response, and “Not sure” is always acceptable.

Question group 1 of 714% complete

Choose the closest answer. The final route should be confirmed with the building control officer or Barlings KWA.

Initial route suggestion

Why this route is suggested

What to do next

Confirm the route before proceeding

Use this result to start a conversation with the building control officer or Barlings KWA. The project drawings, planning conditions and proposed window strategy should be reviewed before the assessment route is agreed.

Ask Barlings KWA to review