Watch the installation

Installation products

Original VELUX
Underfelt collar BFX
Water drainage
Insulation frame
Vapour barrier
collar BBX
Interior lining
Lining frame
kit LSG
Fit exact window
dimensions and
connect perfectly
to your roofing material
Pleated underfelt
collar forms a
tight seal between
roof window and your felt underlay.
drainage gutter
ensures safe
water drainage
from above the

Insulation frame
with flexible foam for a tight and secure fit to the roof construction.
Vapour barrier
collar, including assembly tool for a vapour- and airtight solution.
Prefabricated linings
for easy and airtight inside completion. Includes vapour
barrier collar.
adjustable steel
frame for fast and
easy framing for
your on-site lining. Includes vapour
barrier collar.

Standard or recessed installation

VELUX New Generation roof windows offer two installation heights, standard or recessed. The recessed installation provides a sleek, streamlined appearance, sitting 40 mm deeper in the roof structure, and provides architects with greater design flexibility.

To ensure maximum probability that the declared energy performance is achieved, we recommend installation of the roof window with flashing for recessed installation. When installed with the appropriate VELUX insulation collar, recessed installations result in saving more energy.


Extra insulation and protection

Optimise your new roof window to ensure an energy-efficient and durable installation. You can choose the frame insulation product BDX, which ensures proper insulation between the roof construction and the window frame, and the pleated underfelt collar BFX, which ensures a flexible and tight connection between the underfelt and the window frame. The drainage gutter ensures that water from the underfelt above can drain away from the window.

Download prices and sizes for extra insulation and protection of your roof window

Excellent interior finish