Windows and Doors Installation Pricing UK — Fitting Costs by Window Type (2026)

Overview of Window Installation Costs in 2026

For a standard uPVC casement window, supply-and-fit prices typically run £400–£700 per window for a straightforward ground-floor replacement on a standard reveal. A bi-fold door set — three panels, aluminium frame — sits at £2,500–£4,500 supply and fit, and that figure can climb sharply if a structural opening needs widening or the lintel is inadequate.

Those numbers vary enormously. Material (uPVC, aluminium, timber), glass specification (double or triple glazed, laminated, acoustic, solar control), opening size, floor level, and access all affect what you can realistically charge. This guide focuses on the installer side of that equation — what the labour component looks like, and how to price it so your quotes are competitive and profitable.

Window Types and Typical Installation Labour

Labour rates below are for a competent fitter working on a straightforward domestic replacement — existing opening, no structural work, ground or first floor with easy access. Adjust up for access, reveal depth, or additional making-good requirements.

Casement windows are the most common job and the fastest to fit. A single standard unit rarely takes more than 90 minutes including removal of the old frame, fitting, sealing, and a basic check of the reveal.

Sash windows — whether timber or uPVC box-sash — take longer because the frame construction is more complex, the weights or balance springs need setting correctly, and on older properties the reveal is rarely square. Budget two to three hours per opening and price accordingly.

Bay windows vary the most. A simple three-lite flat bay is one thing; a canted bay with a structural lintel spanning the full width is another. Always inspect before quoting. If the lintel is in doubt, scope that as a variation rather than including a contingency that may or may not be needed.

Roof windows (Velux and equivalents) require working at height — either from internal scaffolding or from the roof — and may need temporary weathering if the roof is opened. The labour range reflects that variability. If scaffold is required, price it as a separate line or instruct the customer to arrange it directly.

Door Types and Installation Labour

Door installation tends to command a higher labour rate per job than windows because the tolerances are tighter — a door that doesn't close flush or draughts at the bottom is immediately obvious to the customer. The figures below are labour only; supply is a separate line on your quote.

Bi-fold doors command the highest labour rates because the track system must be perfectly level and plumb across the full span, every panel needs individual adjustment, and the seals must be set correctly to avoid draughts and water ingress. A full-width bi-fold on a new opening — especially where the structural steel has just been installed — can take a full day for two fitters and should be priced accordingly.

Patio and sliding doors are faster than bi-folds but the track bearing must be level to within a millimetre — out of tolerance and the door becomes hard to slide within months. Check the sub-frame carefully before quoting.

What Affects the Price

These are the most common factors that push a window or door job above the base labour rate. Each one should appear as a named line item on your quote — not absorbed into a single figure that the customer can't interrogate.

• Removal and disposal of old windows: Add £30–£60 per window. This is often forgotten at the quoting stage and creates friction at invoice time if it isn't itemised upfront. If there are 10 windows on the job, that's £300–£600 in disposal costs that your margin can't absorb.
• Lintel replacement: If the existing lintel is cracked, undersized, or rotten, replacing it adds £300–£600 per opening depending on span — and that's before any consequential structural making-good. Never include lintel replacement in a fixed price without inspecting it first. Flag it as a conditional variation in your quote.
• Reveal depth and fitting reveals: A deep reveal adds 30–60 minutes per window. Timber sub-cills, extension profiles, and window boards all take time to cut and fit accurately. Include a line for reveal work or explicitly exclude it.
• Plasterwork around windows: This is not in scope for a glazier. State clearly in your quote that plaster making-good is excluded and that the customer should arrange a plasterer. Leaving this ambiguous costs you time and disputes.
• Access — upper floors and scaffold: First floor typically adds 25–50% to the labour rate. Three-storey or hard-access properties require scaffold, which should either be arranged by the customer or quoted as a separate line by you. Never absorb scaffold cost into a day rate — it's a real cost that varies with the job.
• Energy performance specification: Triple glazing versus double glazing affects the supply cost but not usually the labour rate — the glass unit is heavier, which adds some handling time, but the installation process is the same. If you're supply-and-fit, the uplift is on the materials line, not the labour line.

Supply vs Install Pricing

Some window installers supply and fit; others fit only. Both models work but they require different quoting disciplines.

If you supply and fit: Apply a 20–35% mark-up on top of your trade price for the materials. Your trade price reflects volume, relationship with the supplier, and the credit terms you've negotiated. The mark-up covers your carrying cost, the admin of ordering and chasing delivery, and the commercial risk of being accountable for the material's suitability and quality. Don't treat materials as pass-through — you're taking on the risk, so mark it up.

If you fit only: Quote labour only and state explicitly in your quote documentation that all materials are customer-supplied and that you are not responsible for the quality, specification, or suitability of those materials. This matters for two reasons: first, if a customer supplies the wrong size frame and you fit it, the remedial work is not covered by your quote. Second, if a window fails prematurely, you need a clear record that the failure is in the supplied unit, not your installation. Get the customer to sign off on the specification before you touch it.

Fit-only work is lower revenue but also lower risk. It suits installers who want to fill the diary without tying up cash in stock or managing supplier relationships. The margin is thinner per job but the working capital requirement is zero.

Building Regulations and FENSA

All window and door replacements in England and Wales must comply with Building Regulations Part L (energy efficiency). There are two ways to demonstrate compliance:

1. Notify your local building control authority before the work starts and have them inspect and certify it. This works but creates delays and an additional cost to the customer.
2. Use a FENSA-registered installer (or Certass equivalent), who can self-certify compliance and issue a certificate directly. This is the standard approach for domestic replacement glazing.

FENSA or Certass registration costs roughly £300–£500 per year in membership fees, plus a registration fee per installation. That fee is passed on to the customer as a line item on the quote — typically £15–£40 per installation — or absorbed into your day rate if you're doing volume.

The FENSA certificate goes with the property when it's sold. Conveyancers routinely ask for it, and missing certificates can hold up a sale. Customers who don't think they care about it at the time of installation often care very much when they come to sell. Make sure your quote makes clear that FENSA certification is included — it's a genuine selling point.

If you operate in Scotland, the equivalent is a Building Warrant from the local authority — FENSA does not cover Scotland.

Quoting Tips

Window and door installation is a job type where the quote is the work. Get it right and the job runs cleanly; get it wrong and you're managing variations, disputes, and unhappy customers from day one.

• Always measure on site. Frame sizes are not standard. Measuring from a photograph, a floor plan, or a description over the phone is how you end up with a window that doesn't fit. If a site visit isn't viable before quoting, quote subject to survey and make that condition explicit.
• Check the lintel condition before quoting. A rotten timber lintel or a cracked concrete one is a scope change waiting to happen. If you can't inspect it before quoting, exclude lintel work explicitly and note that a survey will be required. Finding a compromised lintel mid-job when the customer has a fixed price agreement is a bad situation for everyone.
• Include disposal of old windows in your quote. Itemise it as a named line. Customers often assume this is included regardless of what you say verbally, so putting it on paper protects you either way.
• State explicitly whether plaster making-good is in or out of scope. “Excludes plaster making-good around window reveals” should appear verbatim in your quote. If it's in scope, price it accordingly and either arrange the plasterer yourself or coordinate with one the customer nominates.
• Take a 30–50% deposit on supply-and-fit jobs. If you're ordering bespoke windows — and almost all window orders are bespoke — you need the deposit before the order goes in. Windows are made to measure and cannot be returned. A customer who pulls out mid-order leaves you holding stock you can't sell. Deposit terms should be in your contract, not just mentioned verbally.