Build Comply
Part O Overheating Simplified Assessment Method
Part O Overheating Assessment
From Compliant Simplified Methods to TM59 Dynamic Thermal Modelling and Simulation.
Are you looking for a Part O Overheating Simplified Assessment Method?
Building Compliance Testing Limited can provide you with a fast and cost effective Overheating Calculations and Modelling to demonstrate compliance with Part O of the Building Regulations.
Using a simplified method is more cost effective however will not always allow for a compliant result as the assessment only takes into account external glazing location, sizing and cross-ventilation.
Contact us now to get a quotation for your project.
Overheating Mitigation by Design Stage Assessment
The aim of requirement O1 is to protect the health and welfare of occupants of the building by reducing the occurrence of high indoor temperatures. In the Secretary of State’s view, requirement O1 is met by designing and constructing the building to achieve both of the following.
a. Limiting unwanted solar gains in summer.
b. Providing an adequate means of removing excess heat from the indoor environment.
The guidance and regulations are written for the purposes of protecting health and welfare and does not guarantee the comfort of building occupants.
In the Secretary of State’s view, compliance with the Part O Building Regulations can be demonstrated by using one of the following methods.
a. The simplified method for limiting solar gains and providing a means of removing excess heat
b. The dynamic thermal modelling method
Have a project in mind? Let’s get to work.
What is Part O?
The goal of Part O is to limit solar gains within summer and provide adequate means of quickly removing excess heat from indoor environments through ventilation.
At Building Compliance Testing we encourage the design and construction of buildings that limit excessive solar gains to ensure compliance with Part O and ensure the end-users have guaranteed comfort and health
Here at Building Compliance Testing we can demonstrate Part O Overheating compliance through Simplified Method Assessment and TM59 Dynamic Thermal Modelling.
Simplified Method Overheating Assessment
The simplified method for overheating assessment (as outlined in Part O of the Building Regulations) focuses on limiting solar gains and removing excess heat in new residential buildings. It considers factors such as glazing area in proportion to floor space and prescribes minimum free areas for ventilation openings.
It’s not suitable for buildings with large amounts of glazing, bespoke ventilation systems, communal heating systems or significant horizontal pipework.
For dwellings with a glazed area greater than 20% of the room floor area, shading (e.g. louvres, external shutters, etc.) should be provided. Alternatively, the glazing g value should be revised to reduce solar gain in proportion to the increase in glazed area above 20%. The latter should be based on heat gain no greater than an unshaded opening, 20% of the room floor area and a g value of 0.60. If the glazed area is doubled, then the g value should be halved.
Changes to the glass specification to reduce the g value should, where practicable, maintain a high light transmittance. This to minimise the adverse impact on daylighting. A light transmittance of 0.70 or higher is recommended.
By implication, glazed areas of 20% or lower would not require shading or glazing with lower g value than 0.60 when using the simple method.
The Compliance Package: A Multi-disciplinary Approach
At Building Compliance Testing we not only acknowledge risks of overheating. We can take into account air quality, acoustics and ventilation. We specialise in:
- Part F Ventilation – ensuring an adequate ventilation strategy is designed and implemented to ensure overall compliance.
- BS8233 and BS4142 Environmental Noise Assessment – In locations where external noise maybe an issue the overheating mitigation strategy should take account of the likelihood of the windows being closed during sleeping hours. Noisy is defined as 40dB LAeq,T over 8 hours ‘2300-0700’ & 55dB LAFmax, more than 10 times a night. It maybe required to have a noise assessment performed to demonstrate these values are not exceeded.
- Air Quality Assessment – Dwellings near significant local pollution should follow Approved document Part F to reduce the intake of pollutants