Insulation·rigid polyurethane 400mm
rigid polyurethane · 400mm
R 17.39
U 0.057 W/m²·K

rigid polyurethane, 400 mm — R 17.39

400 mm divided by a conductivity of 0.023 gives an R-value of 17.39. The U-value is 0.057, so a square metre leaks 1.14 W across a 20-degree difference.

Standards it meets

  • passive house 0.15
  • Korean central-region wall 0.17
  • loose standard 0.30
Material
rigid polyurethane
Thickness
400 mm
Thermal conductivity
0.023 W/m·K
Thermal resistance
17.39 m²·K/W
U-value
0.057 W/m²·K
Heat lost per square metre
1.14 W
As concrete
27.83 m

Thickness for the same performance

This is the number that shows what insulation is worth. Matching 100 mm of XPS with concrete alone would take 5.7 metres of it. No one builds a wall like that — which is why a concrete building only gets warm once a thin layer of insulation is added.

  • vacuum panel122 mm
  • phenolic foam348 mm
  • extruded polystyrene487 mm
  • graphite EPS539 mm
  • white EPS626 mm
  • glass wool643 mm
  • mineral wool696 mm
  • cellulose730 mm
  • timber2261 mm
  • plasterboard3130 mm
  • concrete27826 mm

Nearby cells

rigid polyurethane 300mm
R 13.04
phenolic foam 400mm
R 20
extruded polystyrene 400mm
R 14.29

Same material, other thicknesses

rigid polyurethane 10mm
R 0.43
rigid polyurethane 20mm
R 0.87
rigid polyurethane 30mm
R 1.3
rigid polyurethane 50mm
R 2.17
rigid polyurethane 70mm
R 3.04
rigid polyurethane 100mm
R 4.35
rigid polyurethane 120mm
R 5.22
rigid polyurethane 150mm
R 6.52
rigid polyurethane 200mm
R 8.7
rigid polyurethane 250mm
R 10.87
rigid polyurethane 300mm
R 13.04
rigid polyurethane 400mm
R 17.39

Same thickness, other materials

vacuum panel 400mm
R 57.14
phenolic foam 400mm
R 20
rigid polyurethane 400mm
R 17.39
extruded polystyrene 400mm
R 14.29
graphite EPS 400mm
R 12.9
white EPS 400mm
R 11.11
glass wool 400mm
R 10.81
mineral wool 400mm
R 10
cellulose 400mm
R 9.52
timber 400mm
R 3.08
plasterboard 400mm
R 2.22
concrete 400mm
R 0.25

How to read this

  • Thermal resistance is the thickness in metres divided by the conductivity. Bigger is better.
  • The U-value adds 0.17 of surface resistance and then flips the total. Smaller is better.
  • Resistances add across layers, so a whole wall is the sum of its parts.
  • Conductivity varies by product; the values here are typical for the material.

Frequently asked questions

Q. What is the R-value of 400 mm of rigid polyurethane?

17.39 — 400 mm in metres divided by a conductivity of 0.023.

Q. And the U-value?

0.057. That is 17.56 — the resistance plus 0.17 of surface — turned upside down, and a square metre leaks 1.14 W across 20 degrees.

Q. How much concrete would match it?

27.83 metres.

Q. Which standards does it meet?

At 0.057 it clears 3 of them.