Prescriptive compliance using glazing limits, shading requirements and ventilation provisions. Suitable for most standard dwelling designs.
Detailed hour-by-hour simulation for complex designs. Demonstrates compliance when simplified method limits are exceeded.
CIBSE TM59 overheating assessments for planning requirements, particularly London developments and local authority conditions.
Early-stage advice on glazing ratios, orientation, shading strategies and ventilation to avoid overheating issues before plans are finalised.
Special provisions for dwellings near roads, railways and airports where windows cannot be opened. Alternative ventilation strategies assessed.
Comprehensive reports for Building Control demonstrating Part O compliance, including all calculations and design recommendations.
Part O is the section of the Building Regulations (England) addressing overheating risk in new residential buildings. Introduced in June 2022, it requires new dwellings to be designed to limit unwanted solar gains and provide adequate ventilation to remove excess heat, protecting occupants from the health risks of overheating.
Part O applies to all new dwellings in England, including houses, flats, conversions to dwellings, and residential buildings. It came into force on 15 June 2022 for projects with Building Regulations applications submitted from that date. It does not apply to existing buildings unless they're being converted to dwellings.
Part O offers two compliance routes: the Simplified Method (prescriptive approach using glazing limits, shading and cross-ventilation rules) or Dynamic Thermal Modelling (detailed simulation demonstrating hours of overheating below threshold). Most projects use the simplified method; complex designs may need modelling.
Key factors include: location (London is highest risk), orientation (south and west facing worst), glazing ratio and g-value, external shading, thermal mass, ventilation strategy (cross-ventilation, purge ventilation), and whether the dwelling is a flat or house. All these are assessed in the Part O analysis.
Part O is a Building Regulations requirement focusing on limiting overheating risk in new dwellings using simplified or modelling approaches. TM59 (CIBSE) is a more detailed overheating assessment methodology often required by planning authorities, particularly in London. We can provide both assessments.