The Quote Says 'We'll Make It Good' — Your Wall Says Something Else

A window quote is a beautifully tidy document. Rows of sizes, a U-value, a total, a tick box marked 'making good included'. Then the fitters arrive, the old frames come out, and the tidy document meets a wall that's been quietly falling apart since before you were born.

This is the part of window replacement that gets the least airtime and causes the most arguments. Not the glass. Not the colour. The hole.

The tidy quote and the messy reality

Removing a window is a demolition job dressed up as a swap. The old frame is usually fixed into a reveal that has been patched, plastered and painted over several times. Behind the plaster there's a cavity, a lintel, a cavity tray if you're lucky, and whatever the last person did in 1998.

A quote that says 'remove existing windows, supply and fit new, make good' isn't lying. It just isn't specific enough to hold anyone to.

Five things that routinely turn up when the frames come out

Plaster reveals. Old plaster around a reveal is usually blown or cracked, and it rarely survives a frame being levered out. The real question is whether making good means a patch, a skim to the reveal, or a full re-plaster and repaint. Those are three very different sums.

Lintels. Steel lintels rust. Timber lintels rot. If the lintel over your opening is failing, a new window can't fix it — and a fitter isn't necessarily a structural engineer. A decent installation shouldn't be propping up a sagging opening with a new frame and hoping for the best.

Cavity trays and weep vents. These are the bits that stop water tracking down the cavity and into your wall. Older installations often don't have them, or have them in the wrong place. Retrofitting a cavity tray during a window change is doable and sometimes necessary — but it's extra work, and it needs designing rather than improvising.

Uneven openings. Victorian and Edwardian openings are rarely square. A new frame can be packed and foamed to suit most of it, but if the opening is badly out — a bowed head, a sloping cill — that needs a conversation before the frame is made, not after it's on the lorry.

Cills, DPC and bay returns. Bay windows are their own genre of trouble: rotten cills, tired roofs, missing damp-proof courses, returns that have shifted. If your quote covers 'one bay window' with no further detail, expect a conversation on day two.

'We'll make it good' is not a specification

Ask five installers what making good includes and you'll get five answers: sealant only; plaster patching; a skim; 'the lad does his best'; full decoration. None of them are wrong, exactly — but only one matches what you're picturing.

The fix is boring and effective. Get a making-good schedule in writing, priced per opening or as a stated allowance. A line like 'plaster skim to reveals, fill and sand, primer coat — decoration not included' is a sentence you can hold someone to. 'Make good as necessary' is not.

Then ask what happens if the wall turns out to be worse than anyone expected. A sensible installer will have a variation process: stop, photograph, price it in writing, get your approval before carrying on. A less sensible one will crack on and invoice you later.

Questions that get a real answer

• Is making good included, and does that mean filler, a patch or a full skim — and is painting in or out?
• What's your rate if a reveal needs more work than expected: day rate, hourly, or a fixed price per opening?
• What do you do if you find a rotten lintel or a missing cavity tray mid-install? Who decides, and who pays?
• Do you fit cavity trays and weep vents as standard on replacements, or only where they already exist?
• Who handles Building Regulations notification — and does that cover structural remedial work or just the window?
• Will you photograph the openings before the new frames go in?
• What's the snagging process, and how long do I have to report cracked plaster or a draughty reveal?

Ask these before signing, while you still have leverage and the scaffold isn't up.

Where the responsibility actually sits

Replacing a window is notifiable work in England and Wales, normally through a competent-person scheme such as FENSA or Certass. That covers compliance with Part L on energy, Part F on ventilation, Part K on glazing safety and Part Q on security — for the window itself.

It does not automatically cover structural alterations. If a lintel needs replacing, or an opening needs rebuilding, that's likely to need Building Control involvement, and it sits outside a standard window contract unless it's written in.

That's not a reason to panic. It's a reason to ask the question early, in plain English, and to get the answer in the paperwork rather than in a van on the driveway.

The contingency conversation

Every honest installer knows the wall is a gamble. The good ones price a small allowance for making good and tell you exactly what happens if it runs out. The bad ones price nothing and argue later.

Budget for it yourself, too. If your quotes all land on the same number with 'making good included' and nothing more, put aside a few hundred pounds per opening for the things nobody can see until the frames are out. If you don't spend it, that's a good week.

Windows are the visible bit. The wall is where the money hides. Get the messy part in writing, and the tidy part gets a lot less stressful.