Better Estimation of Cross-ventilation through Roof Windows in an Attic - Possible Improvement for EN 16798-7:2017

EN 16798-7:2017 considers that windows on roofs that have a pitch below 60° are not included on the windward side whatever their orientation. It means that roof windows are accounted for, but only on the leeward side when using the existing standard for calculation of air flows, EN 16798-7.

Therefore, in the specific case of a room only equipped with roof windows (e.g. an attic) and aeraulically independent from the rest of the building, whatever the orientation of the roof windows, only the simplified “singlesided” calculation method of EN 16798-7:2017 is applicable.