Target page
Wall U-value target 0.25
This comparison page estimates how much insulation is needed to reach the target U-value for a brick wall.
Used for quick thermal checks of walls, roofs, and floors.
Base wall build-up used for the estimate.
Remaining resistance is translated into insulation thickness.
Target U-value 0.25 W/m²K based on a brick wall reference build-up.
How much insulation is needed to reach 0.25 W/m²K?
The comparison example starts from the base wall resistance, subtracts it from the target total resistance, and converts the remaining resistance into thickness.
| Layer | Material | Thickness | Lambda | R |
|---|---|---|---|---|
| Layer | Material | Thickness | Lambda | R |
|---|---|---|---|---|
| Interior finish |
Gypsum plaster
Interior finish
|
1.5 cm | 0.700 W/mK | 0.02 m²K/W |
| Solid ceramic brick |
Solid ceramic brick
Masonry wall leaf
|
25 cm | 0.770 W/mK | 0.32 m²K/W |
| External finish |
Silicone render
Facade finish
|
1.5 cm | 0.870 W/mK | 0.02 m²K/W |
| Mineral wool |
Mineral wool
General insulation
|
12.1 cm | 0.035 W/mK | 3.47 m²K/W |
| Surface resistances | 0.17 m²K/W | |||
| Total resistance | 4.00 m²K/W | |||
Target U-value calculation
R = d / lambda
The target resistance is 1 / U. Once the base wall resistance is known, the remaining resistance can be turned into thickness for a chosen insulation material.
U = 1 / (Rsi + sum(R layers) + Rse)
For this reference page, mineral wool and EPS are compared side by side so the page stays useful without being empty.
Related calculators and guides
Insulation Thickness Calculator
Open insulation thickness calculator for the next step in this journey.
Open hubWall U Value Calculator
Open wall u value calculator for the next step in this journey.
Open next stepHow To Calculate U Value
Open how to calculate u value for the next step in this journey.
Open next stepOpen the calculator
Use the main calculator to edit layers, compare materials, and export a custom result.
Open calculatorR-value vs U-value
Compare the two thermal metrics before choosing a wall or roof build-up.
Open comparisonTarget note
This is a quick reference page for planning. Use the full calculator to verify junctions and detailed layer ordering.
Thickness comparison
Mineral wool and EPS are shown because they are common search targets and give a fast comparison baseline.