There are two techniques for replacing a window. One is quick and clean, the other starts from scratch. The big fitting networks almost always sell the first, even when the second is what is needed. Here is how I decide, frame by frame.
When you replace a window, the real question is not the brand or the colour. It is: what do we do with the old frame? Everything starts there. Either you keep it and fit the new window onto it, or you rip it out and start again from the bare wall. Two philosophies, two prices, and a trap well known to the trade.
A renovation installation (pose en rénovation on a French quote) keeps the existing : I remove the sashes, I clean up, and the new window is fixed onto the old frame, dressed with finishing profiles. No masonry, no dust, one to two hours per window. A full removal (dépose totale) rips everything out, fixed frame included, right back to the masonry. You start from scratch: perimeter insulation redone, maximum glazing dimensions, but the sills, the render, sometimes the wallpaper around them have to be redone. That is half a day per window, and extra finishing work.
| Criterion | Renovation installation | Full removal |
|---|---|---|
| Fitted price | €500 to €800 | €650 to €1,100 |
| Time per window | 1 to 2 hours | Half a day |
| Damage around the opening | None | Render and paintwork to redo |
| Glass area | Reduced (frame on frame) | Maximum, often gained |
| Requirement | Perfectly sound fixed frame | Always possible |
The overall gap comes to around 20 to 30% saved with a renovation installation. That is real. But the figure only means something if the fixed frame deserves to be kept.
The weakness of the renovation installation shows less on the quote than on the wall: you stack a new frame on an old frame, and every frame eats light. Depending on the profiles, you lose 3 to 6 cm of glazed width, as much again in height. On a large opening, nobody notices. On a 60 x 95 cm bedroom window, the visibly melts away, and the room gets darker.
And the worst is renovation on top of renovation. I saw it on a job in Beaudéan: a window already retrofitted in the 2000s, which a salesman was offering to retrofit again. Three stacked frames, glazing reduced to a porthole. There, full removal was the only option, and the room got its original light back.
My honest opinion: the systematic renovation-only approach of the big fitting networks is not a technical choice, it is a commercial one. It is fitted faster, invoiced faster. Fitting new joinery over a decayed frame is papering over the problem: the damp keeps working behind the cladding, and in ten years everything has to be done again. When the fixed frame is doubtful, I refuse the renovation installation, even if the quote across the table is cheaper.
The gold-underlined words are explained on hover. All definitions are in the joinery glossary.
In both cases, what makes the final quality is the seal between the frame and the wall: the caulking, the adjustment, the expanding foam tapes (compriband). A botched full removal does worse than a careful renovation installation. I detail how I work on the window fitting page, and the choice of material on windows and doors. If your current windows are single glazed, also look at the French window replacement grants: the schemes keep changing, so we check together at quote time.
Prod the bottom of the uprights and the bottom rail with a screwdriver, outside and inside. If the tip sinks in easily, if the wood is soft, blackened or crumbling, the frame is done for. Also check that it does not move when you shake it. At the slightest doubt, I come and look: this diagnosis decides everything that follows.
With a renovation installation, I replace a window in one to two hours, with no damage. With full removal, allow half a day per window including the masonry and finishing repairs. Over a whole house, that is the difference between two days and a good week on site.
The installation technique is not the criterion: what counts is the performance of the window (Uw, solar factor) and using a certified professional. The reduced 5.5% VAT applies in both cases if the window performs well. The schemes keep changing, so we check together at quote time.
I come by to see your windows, I probe the frames and I tell you frankly: renovation installation or full removal, window by window. The quote is free and the decision is yours. I speak English, so feel free to call or write in English.
+33 6 03 57 45 47Reply within 48 hours, or in writing: contact@agencementklein.fr
