These sills are designed to work with external insulation and give the appearance of a traditional stone or concrete sill.

Due to passive sills o1 oversills has excellent Insulation value this improves the insulation value by reducing the cold bridging at this point.

Passive sills o1 oversill is a perfect addition to any external insulation project give you a traditional appearance it also has far superior acoustic properties than an aluminium sill during heavy rain and hailstone.