Downloads References Prefabricated Construction Building with Engineered Wood Products

U-Value Calculation

Our database lets you easily calculate the U-values of constructions. Please add layers from our database or create your own product using our technical values. U-values are calculated in accordance with DIN 4108.

Delete all layers

:


Name Thickness Lambda
+ SWISS KRONO OSB 12 0.13
+ SWISS KRONO OSB 15 0.13
+ SWISS KRONO OSB 18 0.13
+ SWISS KRONO OSB 22 0.13
+ SWISS KRONO OSB 25 0.13
+ SWISS KRONO DP50 15 0.09
+ SWISS KRONO WP50 15 0.09
+ Gypsum Paper Board 9.5 0.25
+ Gypsum Paper Board 12.5 0.25
+ Gypsum Fibreboard 10 0.31
+ Gypsum Fibreboard 12.5 0.31
+ PU insulation 0.025
+ Polystyrene 0.038
+ Chipboard 13 0.13
+ Plywood (500 kg/m³) 15 0.13
+ Lime Render 15 0.87
+ Pore Concrete 240 0.29
insert free layer
+
Name Thickness Lambda
+ Fiber insulation 0.032
+ Fiber insulation 0.035
+ Fiber insulation 0.04
insert free layer
+

What is the U-value?

A building part’s U-value, also known as overall heat transfer coefficient, is an important metric. Put simply, it expresses the part’s thermally insulating effect. The U-value indicates how much heat is lost through a single- or multiple-layer part, expressed in W/(m2K). It is equal to the amount of energy that flows through an area measuring one square metre when the air on one side is one degree Kelvin less than on the other side.

The goal is to minimise the U-value, which is the same thing as maximising its thermally insulating effect.

Requirements of the Kreditbank für Wiederaufbau (KfW)

Germany’s Kreditbank für Wiederaufbau (KfW) has established minimum U-values for building parts for improving the energy efficiency of buildings:

Action
Component
Maximum permitted U-value
Thermal insulation of walls
Exterior walls
0.20 W/(m2K)
Walls shared with unheated rooms
0.25 W/(m2K)
Walls in contact with the ground
0.25 W/(m2K)
Thermal insulation of roofs
Roofs of dormers
0.20 W/(m2K)
Dormer cheeks
0.20 W/(m2K)
Flat roofs as main roofs with a maximum pitch of 10°
0.14 W/(m2K)
Thermal insulation of ceilings
Ceilings of top floor below unfinished attics
0.5 W/(m2K)
Ceilings of cellars and unheated rooms
0.25 W/(m2K)
Floors in contact with the ground
0.25 W/(m2K)

Source (available in German only): https://www.kfw.de/KfW-Konzern/Service/Download-Center/F%C3%B6rderprogramme-(Inlandsf.)-(D-EN)/Barrierefreie-Dokumente/Energieeffizient-Sanieren-(151-152-und-430)-Anlage-Technische-Mindestanforderungen-ab-04-2016/index.html

The minimum U-values for new buildings depend on which KfW efficiency house standard they need to comply with. You can find the specifications here (available in German only): Technischen Mindestanforderungen in der Anlage zum Merkblatt Energieeffizient Bauen.

Within Germany, the KfW provides subsidies and other assistance to support construction and renovation projects for more energy-efficient buildings. Depending on the type of building involved, various criteria have to be met to qualify for these programmes.

U-Values of SWISS KRONO System Modules

The SWISS KRONO system modules are wall, roof and ceiling constructions that have been designed in considerable detail and tested under realistic conditions. Here you can verify their properties layer by layer. We have calculated and provided the U-values for these examples, as well as their heat retention and phase shift to show how effectively they protect against.

You can find more information and graphics on our system modules in our download section under “System modules”.

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