Cavity Wall Construction

Passive Sills window sills are designed to work with cavity wall construction and are installed in the same way as a traditional concrete sill.

For the majority of cavity wall construction projects our P1 window sill – 250mm deep with a 50mm upstand – is ideal.

Our sills have excellent insulation value, this improves the overall insulation value of a building by reducing the cold bridging at the point where the sill and window meet

The Passive sills P1 sill is approximately 10% of the weight of a traditional concrete or stone sill and reduces the risk of manual handling injuries on site.

Our window sills are available in our hybrid finish, which has a white paint primer coat and is ready to be painted any colour you choose.

Why choose Passive Sills

Complies with all building regulations

Best for thermal efficiency

Super lightweight

Quick and easy to install

Lower carbon footprint

Best for manual handling

Competitive cost when installed

10 year warranty

Installation Video



Technical Models


Our Finishes

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