Build-up first. U-value second.
Select a typical wall, roof or floor construction, adjust the insulation layer and review the calculated thermal performance. Built for early design checks before a formal calculation pack.
U-value calculator
The tool is intentionally focused: choose the application, check the build-up, tune the insulation and use the output as a design conversation starter.
Build-up templates
Wall · Roof · Floor
Adjustable insulation
Thickness or target-led
Calculation basis
Indicative BR 443 check
Construction build-up
Rainscreen on SFS
External cladding, ventilated cavity, mineral wool and internal lining.
Insulation thickness
Adjust the main insulation layer and watch the build-up update.
Meets the current 0.18 W/m²K target.
- Total resistance
- 5.777 m²K/W
- Surface resistances
- 0.17 m²K/W
- Recommended insulation
- 175 mm
- Layers
- 5
Indicative only. This simplified 1D check uses standard surface resistances and does not include repeating thermal bridges, air movement, point fixings, bracket losses or condensation risk. Confirm with a full BR 443 / BS EN ISO 6946 calculation before specification.
Have an envelope challenge?
Bring us in early. The sooner we engage, the more risk and cost we can design out of your building envelope.