Do I need planning permission for a Velux window in Ireland?

"Velux" is a manufacturer's brand name that has become a generic term for a pitched-roof window fitted flush into the roof slope. For planning purposes there is no distinct "Velux" category — these installations are assessed under Class 8 of Schedule 2 to the Planning and Development Regulations 2001, the same exemption that covers any flush rooflight.

As long as the window sits within the plane of the existing roof rather than projecting outward from it, does not materially alter the shape of the roof, and meets the size and distance-from-eaves conditions in Class 8, no planning permission is needed. This covers the vast majority of ordinary domestic Velux installations used to light an attic or upstairs landing.

The exemption does not extend to a Velux-style window combined with structural alterations that raise or extend the roof, nor does it automatically apply where the house is a protected structure, since roof alterations to protected structures are assessed individually regardless of how flush the window sits.