Dulwich Roofing · Homeowner guide
Warm Roof vs Cold Roof Insulation: What's the Difference?
Warm and cold roof designs place insulation differently relative to the supporting roof structure. That difference changes moisture and ventilation considerations. The right choice depends on the building and a designed roof build-up, not simply the available space.
What the design should explain
- Where insulation and moisture-control layers sit in the assembly.
- How condensation risk is assessed and managed.
- How roof height, edges, rooflights and adjoining walls are affected.
Do not convert between designs by moving insulation alone; ask for a coordinated specification and applicable approvals advice.
Ask for a coordinated specification
The proposed build-up should explain the position of insulation and moisture-control layers, and how it connects to the rest of the building. Changes in roof height can affect thresholds, rooflights and flashings. Ask who is responsible for the design and applicable approvals. Avoid enclosing damp or deteriorated materials without assessment and appropriate repair.
Further guidance: Energy Saving Trust: roof and loft insulation.