Thermal insulation as a U value

Under the current Construction Products Regulations (CPR) manufacturers of external industrial and garage doors must include on the Declaration of Performance (DoP), a *U-value in W/m²K for the door’s performance for the characteristic 'Thermal Resistance'. If no value is being claimed, you need to state “NPD” (No Performance Determined). If declaring “NPD” you are not permitted to make any claims regarding the thermal performance of your product in any of your communication tools.

U-values declared on your DoP must be based upon testing or calculation by a ‘notified testing body’ accredited for the work and listed on the EU’s official website: https://ec.europa.eu/commission/index_en

For industrial doors, such as rolling shutter doors and sectional overhead doors, it was not possible to carry out a test on a full-size specimen based on the test method originally given in the standard EN 13241-1:2003. This method was a test for windows. The issue had been apparent since 2005 when the majority of Member States in Europe were CE marking under the old Construction Products Directive (CPD); in the UK the CE marking under CPD was considered voluntary.

In 2013, the standard EN 12428 was amended to include the calculation method used in Europe and had been approved by the group of Notified Bodies (GNB).  This calculation method, using values for individual components and allowances for cold bridging and leaking points, gives a U-value for a complete door.

To comply with the CPR you must declare the U-value for the complete door on the DoP and CE label; you must not declare the transfer value across the lath or sectional panel.

The declaration must be based on notified body evidence.

*A U-value measures the rate at which heat is lost through the product.

A low value is regarded as a good performance.