How do louvres help compliance with Part O of the building regulations?
Approved Document O came into effect in 2022 and aims to prevent overheating in residential buildings.
Key topics covered:
- What buildings Part O apply to.
- What Part O is designed to do.
- How ventilation louvres support passive cooling strategies.
- The bigger picture of integrating louvres into building designs.
Part O focuses on protecting occupant health and well-being by setting clear standards for managing heat in new dwellings and residential buildings.
To meet the requirements of Part O, designers are required to achieve both of the following: limit unwanted solar gains during summer and ensure that sufficient heat can be removed from indoor spaces. Importantly, it designates that passive measures must take priority, and mechanical cooling systems such as air conditioning should only be used when natural methods are not enough to maintain comfortable conditions.
Ventilation louvres play a key role in supporting compliance with Part O by enhancing airflow within indoor spaces. Although not explicitly required by the regulation, well-designed louvres contribute to passive cooling strategies by enabling effective ventilation to remove excess heat while preventing rain and debris ingress. Louvres are often integrated into external façades, plant rooms, generator housings and ventilation shafts.
For façade engineers, the challenge is to integrate these functional elements seamlessly into the architectural design. Effective use of louvres and other passive ventilation features not only ensures compliance with Part O, but also enhances both a building’s appearance and its environmental performance, delivering comfort, compliance and efficiency.