Reducing overheating – what the new Part O of the Building Regulations could mean for your new house
For those embarking on a residential build, the new Part O of the Building Regulations is an important factor to consider when designing and building your property. The new Part 0 specifically deals with protecting occupants from overheating, caused by the heat generated by the sun over the summer months. Not just limited to solar gain though, the regulations also address overheating caused by uninsulated pipes and lack of heating controls.
Focus is on quickly removing excess indoor heat and mitigating solar gain, particularly relevant with the current and future issues centred around climate change. Rooms will need to be evaluated in isolation and adequate means of cooling must be included to ensure the healthy habitation of the occupants.
The regulations mean consideration needs to be given to the type of glazing you’ll need to install, factoring in the window size and aspect, and potentially the use of external shutters.
Air conditioning can only be used as a last resort if a design solution cannot be found using openings.
When did Building Regulations Part O come into effect?
From 15 June 2022.
If you obtained Building Regulations approval under the old regulations (before 15 June 2022), you must begin work by 15 June 2023 or the new regulations will apply.
Which type of properties does it apply to?
Part O only applies to new dwellings and covers most residential buildings.
Conservatories on new residential buildings must also meet the requirements of Part O.
It does not apply to extensions or conservatories added to residential buildings after they are built, prior to 15 June 2022.
Is Part O Compliance Mandatory?
Yes, compliance is mandatory to demonstrate that provision has been made to remove excess indoor heat and limit unwanted solar gains during the summer months.
How do you calculate overheating in your home?
There are two main ways to calculate overheating risk within a home to identify and mitigate it before building work starts:
- The Simplified Method
The Simplified Method can be used for moderate and high-risk postcode areas for overheating, giving ways to limit and remove excess heat. Check out if you’re in a high-risk postcode area – see the guide below.
There’s a step-by-step guide to using the Simplified Method here: https://www.gov.uk/government/publications/overheating-approved-document-o
- Dynamic Thermal Modelling
Used for more complex buildings, with more detail and greater accuracy, the Dynamic Thermal Modelling method is applied. Using thermal modelling software, an accurate map of potential overheating is created, detailing the risk in specific rooms, by month or even by hours of the day. It is also possible to model different mitigation methods such as glass coatings, shading and shutters or blinds to work out their efficacy.
There’s a comprehensive FAQ available on the government website: https://www.gov.uk/guidance/approved-document-o-overheating-frequently-asked-questions
Planning your new home
Using an experienced professionally qualified architect or architectural designer to help design your home, they’ll help find functional and innovative solutions, and consider suitable façades and windows. Bi Design can help navigate through the new regulations to ensure your home meets the regulations for Part O, yet still deliver your dream home.
Our team at bi Design Architecture are on hand to help with your vision and plan your new home. Get in touch with our team today.
Examples of Integrated solar shading
