What the fitted price covers
A pair of reinforced leaves in a reinforced frame, hung, adjusted and sealed, with the old unit removed and taken away and the reveal made good inside and out. The locking is multi point on the master leaf with full height shootbolts on the slave into the head and threshold.
Adjustment is part of the price and it matters more here than on a single door, because the two leaves have to meet cleanly along an unsupported centre line for the set to seal.
What adds to it
Side panels are the most common addition, and they can be substantial because they widen the frame and add glass. A low or level threshold adds a little. Georgian bars, obscure glass and a colour finish each add modestly.
Structural widening is the variable that matters. Replacing a single back door with a pair often means a wider opening and a new lintel, which is a builder's operation priced after we have looked at what is above the opening.
| Scenario | What to expect |
|---|---|
| Like for like pair into an existing opening | From £1,499 fitted |
| Pair with two side panels | Meaningfully higher, larger frame and glass |
| Single door opening widened to a pair | Add structural work, quoted after survey |
| Low threshold for level access | Small addition, worth it for accessibility |
| Same opening as a two panel slider | Slider from £1,650 fitted |
French doors or a slider on the same wall
Under about 1.8 metres, French doors are usually the better buy as well as the cheaper one, because they give you the whole width open and a slider that narrow feels cramped.
Above that width the calculation flips. A slider costs more but delivers a bigger unbroken view and takes no floor or patio space, and on a narrow patio that practical difference outweighs the price.
Price a pair on your opening
We measure the opening, check the lintel and quote the pair, the threshold and any widening as one fixed written figure.