Windows and doors: Radiation properties
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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:
| Windows | Yes when required |
| Doors | Yes when required |
| Roof windows | Yes |
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
Principles
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.
Standards
| EN 410 | Glass in building – Determination of luminous and solar characteristics of glazing |
| EN 13633-1 | Solar protection devices combined with glazing – Calculation of solar and light transmittance – Part 1: Simplified method |
| EN 13633-2 | Solar 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.
Classification
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:
| Location | npd allowed |
| England and Wales | Probably not |
| Scotland | Probably not |
| Northern Ireland | Probably not |