Overheating Assessments: Part O, TM59 and TM52

Which Overheating Assessment Do You Need?

Every new house, flat, care home and student residence in England needs an overheating assessment under Part O of the Building Regulations. There are two routes. We check which one fits your design before we start, so you do not pay for two reports.

Part O simplified method

The quickest and cheapest route. It checks the glazed area and the window openings of each home against set limits. From £150+VAT per home.

TM59 dynamic assessment

A dynamic thermal model of your building, run hour by hour against summer weather data. It is the route for heavily glazed or single-aspect homes, blocks of flats with communal heating, sites where windows cannot be left open at night, and major planning applications in London. From £500+VAT.

Commercial buildings: TM52

For offices, schools and other non-domestic buildings we carry out overheating assessments to CIBSE TM52. See TM52 overheating assessments for the criteria, weather files and what we need.

If the design does not pass

We tell you what to change: smaller or different glazing, shading, or more opening area. If the simplified method will not work, the next step is a dynamic model.

We can run the SAP calculations and the Part G water calculation from the same drawings.

Email your drawings or WhatsApp us for a free quote.