FAQ: The abbreviation FENSA stands for FENESTRATION - SELF ASSESSMENT.
The uk dictionary definition of the word fenestral or fenestrate is " belonging to or like a window" The word fenestration is "the arrangement of windows in a building". FENSA is used by double glazing uk trade companies to certify that their replacement windows and doors installed comply with Building Regulations Document L (and more), actually checking av. 1% of all replacement windows installations.
Did You Know?
Don't laugh, this is a serious subject
You may be surprised to hear that the old steel 'Crittal' type windows that we loved to hate are still alive and kicking, and even more surprised to see that they are now available double glazed.
Not as silly as it seems, these are an excellent and unbeatable alternative in situations where integral strength and low profile sizes have a high importance. However, these are not really a viable alternative for the average home as the framework lacks the thermal properties most will demand of a new window.
Fitting these is much the same as fitting any window but to give maximum weather performance the frames should be set back 75mm from the face of the wall. A sub-frame is only necessary if there is a need for a bolder look, and there steel systems that can be installed directly to the fabric of the building without a sub-frame.
The most important thing about steel windows is to remember that if you repaint, do not sand down the surface and break through the galvanizing. Ever wondered why you often see a cracked pane of glass in a Crittal, well it's often the rust putting pressure on the glass!
More information on steel windows can be obtained by visiting their less than exiting website (they did email me and point out that it is an information website though, and really only meant for certain circles of the trade only).
The use of steel windows in commercial fenestration and curtain walling is still a very serious consideration and often chosen by the experts as the best of the alternatives available.