U-Value Calculations

To meet Building Regulations Part ‘L’

The U-value represents the thermal conductance of a given structure, for example an entire roof. The lower the u-value achieved – the better the level of insulation.

The R-value represents the thermal resistance of a given component within the structure, for example an insulation product. The higher the R value rating – the better the product.

Below are just a few examples of how different U-values can be achieved, we have many more on file and U-value calculations can be done for any specific type of construcion.

0Roof insulated under rafters

Insulating below the rafters is referred to as a ‘cold roof’ solution. Current regulations require a U-value of 0.18W/m2K. For an existing roof, upgraded as part of a retrofit project, the U-value requirement is 0.2. your options include:

 

0Roof insulated over rafters

Insulating above the rafters is referred to as a ‘warm roof’ solution. Current regulations require a U-value of 0.18W/m2K. For an existing roof, upgraded as part of a retrofit project, the U-value requirement is 0.2. your options include:

 

 

Solid/Cavity Walls

Currently the U-value requirement for an new wall is 0.28W/m2K. For an existing wall upgraded as part of a retrofit project, the U-value requirement is 0.3

Timber walls

Floor Insulation   - new & existing floors

Currently the U-value requirement for an new floor is 0.22 W/m2K. For an existing floor, upgraded as part of a retrofit project, the U-value requirement is 0.25. To achieve or exceed the required U-value your options include:

For more roof, wall and floor U-value calculations please contact us