Windows and doors > Air permeability

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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:

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 p> 


The window, door or roof window shall prevent excessive passage of air.

The tests for air permeability of screens shall be carried out on the screen or on its individual parts including joints between the individual parts. In the latter case the air permeability of the screen shall be calculated as the sum of the air permeability of the individual parts and the joints.


EN 1026Windows and doors. Air permeability. Test method
EN 12207Windows and doors. Air permeability. Classification


Method of test

The test method is described in EN 1026. The window is mounted on a test box and air leakage is measured for both positive pressure difference (infiltration)and negative pressure difference (Exfiltration).


The class of performance is given as a number indicating the peak test pressure and air permeability at 100 Pa as listed below:

ClassPeak test pressureAir permeability at 100 Pa
0Not testedNot tested
1150 Pa50 m3/h/m2
2300 Pa27 m3/h/m2
3600 Pa9 m3/h/m2
4600 Pa3 m3/h/m2


CE Marking

UK Regulations make no specific requirements for air permeability of components but a particular whole building air permeability is required:

Locationnpd allowed
England and WalesProbably not
ScotlandProbably not
Northern IrelandProbably not