Fixing and buying guide

Who this product is for

This insulation collar is for builders, roofers, and serious DIY installers fitting VELUX PK08 2000 roof windows or Sun Tunnel systems. It is essential for both new roof window installations and refurbishment work where thermal efficiency and weather-tightness are required.

Compatibility and sizing

The BDX PK08 2000 collar is specifically designed for the VELUX PK08 2000 roof window range. The 940 x 1400mm dimensions are fixed to this window size, so you must confirm your roof window model before ordering. This collar will not fit other VELUX window sizes or non-VELUX systems.

• Compatible only with VELUX PK08 2000 roof windows
• Fixed size: 940 x 1400mm – no adjustment possible
• Also compatible with VELUX Sun Tunnel systems designed for PK08 2000 apertures

What you get and pre-installation checks

Each collar is supplied ready to fit around your roof window opening. Before installation, verify that your roof window is a genuine VELUX PK08 2000 model and check the opening dimensions match 940 x 1400mm. Ensure the roof structure is sound, the opening is square and level, and that any existing flashing or sealing is removed. The collar must be installed before the roof window is fully sealed to create a continuous thermal and weather-tight barrier.

• Check roof window model is VELUX PK08 2000
• Verify opening dimensions are 940 x 1400mm
• Confirm roof structure is sound and opening is square and level
• Remove any old flashing or sealant before fitting

Installation and performance

The insulation collar should be fitted as part of the complete roof window installation sequence, creating a thermal and weather-tight seal between the window frame and the roof structure. Proper installation ensures the collar performs reliably in UK weather conditions and maintains visual consistency across the roof line. For detailed fitting instructions and professional support, refer to VELUX installation guidance or consult a qualified installer.

• Forms part of the complete thermal and weather-tight seal
• Must be installed correctly to maintain performance in UK roof conditions
• Supports a professional, visually consistent roof finish
• Professional installation support available from VELUX