A window is only truly energy efficient if it is constructed from a sustainable material and Rationel have invested hugely in the sustainability of their windows.
Rationel window are constructed from timber and alu-clad timber frames. All timber used in the construction of their window frames is FSC certified. Using FSC certified timber has many benefits to the environment including:
Rationel is also a member of the Wood Window Alliance, setting standards for high performance windows and doors. Choosing a window that has been approved by The Wood Window Alliance ensures that your windows have been manufactured to the very highest standards. The Wood Window Alliance guarantees all of their accredited windows achieve; long life, low maintenance, energy efficiency, sustainability, low carbon footprint, BS 644 design, security and accredited installation.