Regarding the reuse of window frames, one question that immediately comes to mind is that of energy performance. Windows are effectively a focal point in current projects and play a crucial role in meeting modern requirements in terms of heat insulation and air tightness.
In fact, two specific cases apply here:
Firstly, very old window frames made of wood and sometimes fitted with stained glass, sought after for their aesthetic quality and materiality. As they were not designed with energy performance in mind, these frames are generally used in such applications as interior design, heritage-based restorations or unheated spaces.
Alternatively, modern frames that meet stricter performance requirements can be found on the reuse market. These are frames recovered from the demolition of more recent buildings, or even new frames from surplus production. Another scenario is where a communication error leads to the production of frames that do not fit the gaps that have to accommodate them, leading to the disqualification of the batch delivered to the site.
Working with reusable frames requires designers to modify their working processes slightly: the bays for the windows need to be sized according to the frames. But it is often worth the trouble as, with greater dimensional tolerance, it becomes possible to acquire high-quality elements at competitive prices and consequently to reduce the cost of an important category in building projects.
The most frequently encountered products include:
modern, double-glazed window frames, in wood, PVC or aluminium
old wooden window frames, some with stained glass
old skylight frames (for roofing)
The prices for modern reusable frames vary between 20 and 40 % of the new equivalent prices.