Insulation·extruded polystyrene 10mm
extruded polystyrene · 10mm
R 0.36
U 1.897 W/m²·K

extruded polystyrene, 10 mm — R 0.36

10 mm divided by a conductivity of 0.028 gives an R-value of 0.36. The U-value is 1.897, so a square metre leaks 37.94 W across a 20-degree difference.

Standards it meets

Not up to any of them yet

Material
extruded polystyrene
Thickness
10 mm
Thermal conductivity
0.028 W/m·K
Thermal resistance
0.36 m²·K/W
U-value
1.897 W/m²·K
Heat lost per square metre
37.94 W
As concrete
0.57 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 panel3 mm
  • phenolic foam7 mm
  • rigid polyurethane8 mm
  • graphite EPS11 mm
  • white EPS13 mm
  • glass wool13 mm
  • mineral wool14 mm
  • cellulose15 mm
  • timber46 mm
  • plasterboard64 mm
  • concrete571 mm

Nearby cells

extruded polystyrene 20mm
R 0.71
rigid polyurethane 10mm
R 0.43
graphite EPS 10mm
R 0.32

Same material, other thicknesses

extruded polystyrene 10mm
R 0.36
extruded polystyrene 20mm
R 0.71
extruded polystyrene 30mm
R 1.07
extruded polystyrene 50mm
R 1.79
extruded polystyrene 70mm
R 2.5
extruded polystyrene 100mm
R 3.57
extruded polystyrene 120mm
R 4.29
extruded polystyrene 150mm
R 5.36
extruded polystyrene 200mm
R 7.14
extruded polystyrene 250mm
R 8.93
extruded polystyrene 300mm
R 10.71
extruded polystyrene 400mm
R 14.29

Same thickness, other materials

vacuum panel 10mm
R 1.43
phenolic foam 10mm
R 0.5
rigid polyurethane 10mm
R 0.43
extruded polystyrene 10mm
R 0.36
graphite EPS 10mm
R 0.32
white EPS 10mm
R 0.28
glass wool 10mm
R 0.27
mineral wool 10mm
R 0.25
cellulose 10mm
R 0.24
timber 10mm
R 0.08
plasterboard 10mm
R 0.06
concrete 10mm
R 0.01

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 10 mm of extruded polystyrene?

0.36 — 10 mm in metres divided by a conductivity of 0.028.

Q. And the U-value?

1.897. That is 0.53 — the resistance plus 0.17 of surface — turned upside down, and a square metre leaks 37.94 W across 20 degrees.

Q. How much concrete would match it?

0.57 metres.

Q. Which standards does it meet?

At 1.897 it does not clear any of them yet.