Sector
Residential
MEP design for apartment buildings and housing, including heat networks, ventilation and overheating assessment.
OVERVIEW
Residential building services have moved a long way in a short time. Heat decarbonisation has displaced the individual gas boiler as the default, overheating assessment has become a design requirement rather than a courtesy, and ventilation has come under much closer scrutiny.
Apartment buildings in particular concentrate the difficulty: communal heat distribution, ventilation in single aspect flats, and an overheating risk that is highest in exactly the well insulated, highly glazed dwellings the fabric standards encourage.
DESIGN
What drives the design
Overheating is now assessed, not assumed
TM59 sets the methodology for homes, and in England Approved Document O makes overheating mitigation a Building Regulations requirement. Both are best addressed while glazing, shading and ventilation are still open questions.
Heat networks and distribution losses
Communal heat networks fail on distribution loss far more often than on generation. Pipe sizing, insulation and control of the secondary side determine whether the system performs as designed.
Ventilation in single aspect dwellings
Where cross ventilation is not available, mechanical ventilation with heat recovery is usually the answer, and its duct routes need to be resolved before the ceiling voids are fixed.
REGULATION
Statutory and guidance documents
Scotland and England take different statutory routes. Where a document applies to one and not the other, it says so.
- Approved Document OOverheatingEngland and Wales
- Approved Document FVentilationEngland and Wales
- Approved Document LConservation of fuel and powerEngland and Wales
- Technical Handbook Section 3EnvironmentScotland
- Technical Handbook Section 6EnergyScotland
- CIBSE TM59Assessment of overheating risk in homesUK-wide
- CP1Heat Networks Code of PracticeUK-wide
SCOPE
Typical scope in this sector
- Apartment building MEP design
- Communal heat network design
- MVHR design for single aspect dwellings
- Overheating assessment to TM59
- Landlord and dwelling metering strategy
QUESTIONS
Common questions
Is overheating assessment a legal requirement for new homes?
In England, Approved Document O makes overheating mitigation a Building Regulations requirement for new residential buildings, with two compliance routes — a simplified method and dynamic thermal modelling. CIBSE TM59 sets out the assessment methodology commonly used for the modelling route.
SERVICES