Our passive window sills are designed to work with Insulated Concrete Formwork (ICF) construction and are installed in the same way as a traditional concrete sill.

For most ICF builds we recommend our P9 passive sill – 225mm deep with a 50mm upstand. 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. It also improves the overall performance of your window.

The Passive Sills P4 window 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.