Because windows and doors can be built and glazed in various ways, a standardised banding system is used to demonstrate their thermal performance. Developed by the British Fenestration Rating Council, it oers homeowners a simple method of comparing windows and doors. It covers thermal insulation, solar gain and air leakage. Originally the scale ran from A to G, but standards have improved and now the best-performing windows
and doors are rated A++.
The Optima system is capable of achieving this A++ rating, and not only that but a U-value of 0.8 W/m2K. this measure, which looks at insulation, is sought by the Passivhaus movement which aims to produce buildings which need very little heating or air conditioning and which, therefore, have very low running costs.
For ultimate thermal performance and a comfortable home,
Optima is ideal.