FAQ
Why this calculator is useful
Built for fast checks, reporting, and practical early-stage decisions.
Walls, roofs, and floors
Model layered building assemblies and compare thermal performance across common envelope elements.
Report-ready output
Print or export a clean summary with material layers, resistance values, and project metadata.
Insulation comparison
Compare materials by lambda, resistance, and thickness to quickly shortlist the best options.
Standalone answers
What is lambda?
Lambda is the thermal conductivity of a material in W/mK. Lower values usually mean better thermal insulation.
What is U-value?
U-value describes how much heat passes through a building element. Lower U-values indicate better thermal performance of the full assembly.
Can I compare materials?
Yes. Use the comparison section to choose a category, set a thickness, and compare materials by lambda and calculated thermal resistance.
Can I print or export the result?
Yes. You can print the result or export it to CSV, Excel, or PDF for reporting and documentation.
Does the calculator work for walls, roofs, and floors?
Yes. It is designed for layered assemblies such as external walls, flat roofs, pitched roofs, floors, and slabs.
Is the calculator suitable for quick design checks?
Yes. It is intended for fast concept-stage calculations, insulation comparison, and envelope optimisation before detailed design.
Can I switch thickness units?
Yes. You can switch between millimeters, centimeters, and inches, and the calculator keeps the values consistent.
Pages worth separating next
Wall calculator
A dedicated page for external walls with target U-value content and wall-specific FAQs.
Roof calculator
Separate landing page for flat and pitched roofs, including roof build-up examples.
Floor calculator
A floor-on-ground or slab page with the relevant assumptions and comparison presets.
Insulation comparison
A focused comparison page for insulation-only queries, lambda sorting, and target thickness.