Last edited 20 Feb 2018

Main author

Sarah Peterson Engineer Website

BREEAM Thermal comfort


[edit] Aim and benefits

To make sure buildings users are warm enough in the winter, cool enough in the summer, and can have control over their own heating.

(In UK NC 2014) There are 3 credits:

  • Is your building cool enough in the summer and warm enough in the winter?
  • In the future with climate change, will your building still be thermally comfortable?
  • Have you got thermal zones and controls so building users can control their own thermal comfort?

[edit] When to consider

See Step by step guidance below for some guidance on actions with regards to the RIBA timeline.

The analysis should lead the design so ideally it should be carried out at concept design stage. RIBA Stage 2 - 3.

[edit] Step by step guidance

[edit] Pre-Assessment

Is your building comfort cooled? If yes, you should achieve credits 1 and 2, as long as your system is sized OK.

Is your building mechanically ventilated? If yes, you’ll probably achieve the credits. Is your building fully naturally ventilated? If yes, you should achieve the first credit, but the climate change one will be really tricky.

There’s no excuse in this day and age for not achieving the 3rd credit. Note, in a school situation, it might only be that FM can control the heating/cooling so that kids don’t keep changing TRVs etc. In retail buildings/prisons etc the credit only refers to staff controlling temperature.

[edit] RIBA Stage 2

Check overheating risk as part of initial Part L and thermal modelling. Start putting together a thermal zoning and control strategy. Consider:

  • the type of people that will use the building
  • how au fait they will be with the different types of equipment
  • how often they’ll be using the spaces and what the spaces will be used for
  • How do individuals want to interact with heating/cooling controls?
  • How can you balance different peoples’ requirements?
  • How will the systems interact with each other?
  • Does there need to be an override so systems aren’t used totally inefficiently?

Work out how many heating/cooling zones are appropriate. Do central cores need separate heating to perimeter areas in large rooms?

[edit] RIBA Stage 3

Produce thermal comfort report, covering winter comfort and overheating. Finalise zoning and controls strategy. Include these in a report (could be your stage report, or a stand-alone report)

Modelling should be carried out using dynamic simulation software (IES or TAS for example) an be in accordance CIBSE AM11, ensure this is referenced in any report used as BREEAM evidence.

[edit] RIBA Stage 4

Unless there are any major design changes relating to heating and cooling, you’re done.

[edit] RIBA Stage 5

If you’re working for an M&E sub contractor you may need to produce a markup of an as built drawing showing the zones and controls. You may also have to confirm formally that there have been no changes to the design which would affect the overheating risk, or make the building too cold in the winter. The BREEAM assessor will take a bunch of photos of the site showing that there are heating and cooling systems as per the design.

[edit] Questions to ask while seeking compliance

What is the thermal comfort criteria?


[edit] Tools and resources




[edit] Tips and best practice

Don't forget winter time thermal comfort

TM52 isn’t a limiting stop. A building won’t necessarily be comfortable because you met TM52. Try not to let the thermal zoning exercise feel like “something you just have to do for BREEAM” – control strategies are a really important part of soft landings and trying to reduce the performance gap


[edit] Typical evidence


BRE Global does not endorse any of the content posted and use of the content will not guarantee the meeting of certification criteria.

--Sarah Peterson 15:39, 20 Feb 2018 (BST)