Windows and doors: Radiation properties

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Categories: Performance : Windows & Doors

The performance characteristics listed below are relevant to products covered by EN 14351-1 Windows and doors - Product standard, performance characteristics - Part 1: Windows and external pedestrian doorsets without resistance to fire and/or smoke leakage characteristics

This requirement applies to:

WindowsYes when required
DoorsYes when required
Roof windowsYes

Doorsets and openable windows with fire resisting and/or smoke control characteristics are covered by EN 14600

Pedestrian doorsets, industrial, commercial, garage doors and windows are covered by prEN 16034


Windows, doors and roof windows should limit solar transmittance to reduce solar gain in a building if required.

Windows, doors and roof windows should allow adequate light transmittance to limit the need for artificial lighting if required.


EN 410Glass in building – Determination of luminous and solar characteristics of glazing
EN 13633-1Solar protection devices combined with glazing – Calculation of solar and light transmittance – Part 1: Simplified method
EN 13633-2Solar protection devices combined with glazing – Calculation of total solar energy transmittance and light transmittance – Part 2: Detailed calculation method


Method of calculation

Assessment is on the basis of calculation. Methods of calculation are given in the Standards listed above.


There is no classification for the radiation properties of the curtain wall. The Product Standard requires the total solar energy transmission and the light transmission to be declared.

CE Marking

The Building Regulations do not give explicit limits to the g-value or light transmission of a window, door or roof window. Solar gains during the summer have to be limited and this is demonstrated by taking the solar gains through the glazing aggregated over the period from April to September inclusive and comparing the result to a reference glazing system. The allowable use of No Performance Determined (npd) is as follows:

Locationnpd allowed
England and WalesProbably not
ScotlandProbably not
Northern IrelandProbably not