EPS / Mineral Wool → PIR Conversion
Have EPS, mineral wool or XPS in your project? Check the equivalent thickness in termPIR® insulation — keeping the same thermal resistance (R). PIR has the best λ on the market (0.019-0.027 W/(m·K)), so the thickness can be significantly reduced.
What do you have in your project?
Your R
—
m²·K/W (thermal resistance)
Equivalent termPIR® thicknesses (same R)
📐 Conversion formula
ThicknessPIR = Thicknessoriginal × (λPIR / λoriginal)
Rounding: termPIR® is produced in 10 mm increments — result rounded up to nearest 10 mm for project safety. izoGRASS® is cut to size — exact thickness shown without rounding.
🧮 U-value Calculator
Check if your layer system meets Polish WT 2021. With a 50+ materials library.
📚 termPIR® product line
Full BOKKA PIR boards offer — AL, WS, MAX 19, AGRO, ETX, Prime and others.
💬 Ask an advisor
Unsure if conversion makes sense for your project? Our technical advisor will prepare a recommendation.