extruded polystyrene · 150mm
R 5.36
U 0.181 W/m²·K
extruded polystyrene, 150 mm — R 5.36
150 mm divided by a conductivity of 0.028 gives an R-value of 5.36. The U-value is 0.181, so a square metre leaks 3.62 W across a 20-degree difference.
Standards it meets
- loose standard 0.30
- Material
- extruded polystyrene
- Thickness
- 150 mm
- Thermal conductivity
- 0.028 W/m·K
- Thermal resistance
- 5.36 m²·K/W
- U-value
- 0.181 W/m²·K
- Heat lost per square metre
- 3.62 W
- As concrete
- 8.57 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 panel38 mm
- phenolic foam107 mm
- rigid polyurethane123 mm
- graphite EPS166 mm
- white EPS193 mm
- glass wool198 mm
- mineral wool214 mm
- cellulose225 mm
- timber696 mm
- plasterboard964 mm
- concrete8571 mm
Nearby cells
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
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 150 mm of extruded polystyrene?
5.36 — 150 mm in metres divided by a conductivity of 0.028.
Q. And the U-value?
0.181. That is 5.53 — the resistance plus 0.17 of surface — turned upside down, and a square metre leaks 3.62 W across 20 degrees.
Q. How much concrete would match it?
8.57 metres.
Q. Which standards does it meet?
At 0.181 it clears 1 of them.