How to Prepare for a Window Replacement Project: Survey to Installation

A typical whole-house window replacement runs: quotation (days), technical survey (an hour or two on site), manufacture of your made-to-measure frames (usually four to six weeks), then installation at a rate of roughly two to four windows per day, finishing with sealing, making good and handover paperwork. Knowing what happens at each stage — and what is expected of you — is most of what makes a project feel smooth rather than stressful.

Stage 1: Getting quotes that can be compared

Start with approximate sizes (width × height per opening, measured to the nearest centimetre is fine at this stage), photos of each elevation, and a note of what opens where. That is enough for a serious quotation — ours usually comes back within two to three working days. When quotes arrive, check they cover the same things: the same openings, glazing build-up, thermal tier, colours, security spec, installation scope, waste disposal and guarantees. Our guide to what drives window costs explains the lines you will see.

Stage 2: The technical survey

Once you choose a supplier, a surveyor measures every opening properly: diagonals, reveal depths, cill conditions, lintel positions and squareness — old openings are rarely square, and the frames are made to the survey, not to the brochure. This is the moment to finalise every decision, because manufacture starts from these numbers: opening directions, trickle vents, obscure glass locations, handle colours, cill projections, threshold details. Changing your mind after survey means remaking frames.

Good surveyors also flag the awkward realities early: rotten timber subframes, cracked lintels that need attention before fitting, or conservation-area constraints on appearance.

Stage 3: The wait — and what to do with it

Made-to-measure aluminium frames typically take four to six weeks to fabricate; bespoke finishes and oversized sliding sashes can take longer. Your quotation confirms a firm date. Use the time to:

• Confirm building-control arrangements — replacement windows are notifiable work, normally handled through the installer's certification scheme (you should receive a certificate at the end; keep it, solicitors ask for it when you sell).
• Check whether your property is listed or in a conservation area, if not already resolved at survey.
• Plan room access: installers need a clear path to each window and space to work on both sides.
• Tell your neighbours if scaffolding or shared access is involved.

Stage 4: Installation week

A realistic pace is two to four windows per day, one to two days for a large sliding or bi-folding door, and a day for an entrance door set. For each opening the sequence is: protect the room, remove the old frame, prepare and square the opening, fix the new frame with correct packers and fixings, glaze, seal inside and out, fit handles and vents, and make good the reveals.

What to expect honestly: it is disruptive but rarely as bad as feared. Rooms are worked one at a time, openings are never left unsecured overnight, and dust sheets deal with most of the mess — though some redecoration around reveals is normal on older properties, and it is worth asking in advance how making-good is handled.

Your role during the week: clear a two-metre zone in front of each window, take down curtains and blinds, move fragile items, keep pets and children clear of work areas, and walk each room with the fitters as it is finished rather than saving every question for the last day.

Stage 5: Snagging and handover

Before the team leaves, check each window: opens, closes and locks smoothly; restrictors and trickle vents work; glass is unscratched and the right specification (look for the spacer-bar etching); sealant lines are clean and continuous; keys are present for every lock. Then gather the paperwork — building-control certificate, guarantee documents for frames, finish, hardware and glazed units, and care instructions. SIVAL systems carry a lifetime structural profile warranty and up to 25 years on the finish; guarantees are transferable if you sell.

Choosing who does the work

The installer decides more of the outcome than the frames do, so choose deliberately. Reasonable checks: how long the firm has traded under its current name; recent local installations you can actually look at; membership of a competent-person scheme so your building-control certificate is issued automatically; whether the workmanship guarantee is insurance-backed (so it survives if the firm doesn't); and who you call in year three if a handle drops or a unit mists. SIVAL supplies through a vetted network of approved fabricators and installers, each trained on our systems — so the people fitting the frames know them from the inside, and the workmanship guarantee sits alongside the product guarantees rather than instead of them.

Common pitfalls worth avoiding

• Deciding late. Handle colours, obscure glass and opening directions changed after survey mean remade frames and reset lead times.
• Comparing unlike quotes. A lower number that excludes disposal, making good or certification is not a lower price.
• Ignoring the cills and reveals. Agree in writing how external cills, internal boards and plaster reveals are handled — it is the most common source of end-of-job friction.
• Losing the paperwork. The building-control certificate and guarantees are part of your house's sale file; scan them the week you receive them.

Aftercare in one paragraph

Wash frames with warm soapy water twice a year (quarterly near the coast), keep drainage slots clear, lubricate hinges and locks annually, and avoid abrasive cleaners on the powder coat. That is genuinely all aluminium asks for the next few decades.

Ready to start?

Send your rough sizes and photos through the quote form and we will take it from there — quotation, survey through our approved installer network, and a firm programme before any work begins.