The Cheap Quote That Stops at the Kerb: What Supply-Only Windows Leave You to Sort

Supply-only quotes have a way of looking like the sensible option. The number is smaller, the specification is clear, and nobody is trying to sell you an extended guarantee you did not ask for. Then the windows arrive on a pallet, the driver asks where you want them, and you realise the project has quietly changed hands.

That is not to say supply-only is a con. It is a legitimate way to buy windows, and for some people it is exactly right. But it is a different product from a supply-and-fit quote. One is a set of frames and glass. The other is a finished job with someone else’s name against the fitting, the sealant, the old frames and the building-regulations notification. Comparing the two headline prices without comparing the responsibilities is how homeowners end up holding a tape measure and a phone, wondering who was supposed to order the cills.

The headline price is for a product, not a project

A supply-only quote is usually priced on the assumption that you know exactly what you are buying and exactly what will happen once it is delivered. The supplier makes the windows to the sizes and specification agreed. You arrange the rest. That can include measuring, checking access, receiving delivery, storing the units, hiring a fitter, disposing of the old frames and glass, making good inside and out, and making sure the work is signed off where it needs to be.

None of those things are mysterious. But each one has a cost, and each one has a way of going wrong. A supply-and-fit quote bundles them into one price and, crucially, one point of responsibility. A supply-only quote pushes them back to you. The cheaper number is not necessarily a worse deal — it is just a narrower one.

Measuring is now your job, and your risk

This is the big one. Many supply-only suppliers will ask for sizes “as measured by the customer” or “as supplied”. That phrase is doing a lot of work. If a frame is 10mm too wide, or the reveal is out of square, or the bay has a lean you did not account for, the supplier can reasonably say the windows were made to your measurements. Replacements become your cost, not theirs.

Some suppliers offer a survey for an extra fee. Take it seriously if they do. Ask what tolerances they allow, whether they check diagonals and levels, and who signs off the final sizes. If you are measuring yourself, use a proper tape, measure in several places, and photograph every opening with the tape visible. It sounds fussy. It is much less fussy than trying to argue about a bespoke frame that does not fit.

Delivery is a moment, not a service

“Delivery included” can mean a pallet left at the kerb, a two-person lift to your hallway, or a full placement in the room of your choice. Those are very different things. Ask where the driver will leave the units, whether they will help carry them, and what happens if you are out. Windows are bulky, heavy and easily damaged. Check the delivery insurance and the deadline for reporting damage — often it is measured in hours, not days.

You also need somewhere dry and secure to store the windows before fitting. A driveway is not a storage facility. Neither is a front garden under a tarpaulin in a wet week. If the fitter cannot start for a fortnight, where are the frames going? And who is paying if a unit gets scratched or knocked while it waits?

Fitting is the bit that decides whether it was a bargain

A well-made window fitted badly is a badly performing window. It can leak, draught, mist up, stick, or fail to close properly. The product guarantee may still be valid, but it will not cover poor installation. That is why the identity of your fitter matters as much as the identity of your supplier.

Ask whether the supplier has approved installers, whether they will warrant the product when fitted by a third party, and what evidence they need. Check the fitter’s insurance, their experience with your frame type, and how they will handle access, scaffolding, lintels, cavity closures and insulation. Replacement windows also need to meet building regulations on energy performance and, in many cases, be notified or covered by a competent-person scheme. If nobody has mentioned that, somebody needs to.

Old frames, glass and the paper trail

Disposal is one of those jobs that looks small until it is three skips later. Old uPVC frames, glass, packaging and sealant tubes all need to go somewhere legitimate. Ask whether the supply-only price includes takeaway. Usually it does not. Ask your fitter, too. A cheap fitter who leaves the old frames in your garden has not saved you money; they have moved the cost to you.

Then there is the paperwork. Keep the order confirmation, the sizes you supplied, the delivery note, photographs of the damage before you signed for it, the fitter’s invoice and any building-regulations certificate. If you sell the house, or make a guarantee claim, that paper trail is your evidence.

Guarantees get split down the middle

A supply-only guarantee usually covers the product: the frames, glass, hardware and maybe the sealed units. It does not usually cover the labour, the seal between frame and wall, or the way the window was installed. If the fitter causes a problem, you may be dealing with two companies who each point at the other. That is not impossible to manage, but it is your time and your phone calls.

Before you choose supply-only, read the guarantee terms for what is excluded. Ask whether the warranty requires installation by a named competent person. Ask who pays for labour if a sealed unit fails and has to be swapped. Ask how long the guarantee lasts and whether it is transferable. The answers will tell you a lot about how the supplier sees the boundary between their product and your project.

Seven questions before you choose supply-only

1. Are the sizes my responsibility, or will you survey and sign them off?
2. What exactly does delivery include — kerbside, driveway or room of choice?
3. How long do I have to report damage, and what evidence do you need?
4. Does the product guarantee stay valid if I use my own fitter?
5. Who is responsible for building-regulations notification or competent-person certification?
6. Is old-frame and glass disposal included, and who provides the waste paperwork?
7. What is the realistic total once survey, fitting, access, disposal and making good are added?

When supply-only makes sense

Supply-only can work well if you are a builder, a competent DIY installer, or managing a renovation with a trusted fitter already on site. It can also suit simple openings where you are confident in the measurements and happy to carry the risk. What it rarely suits is a homeowner replacing a few windows for the first time, expecting the same experience as a supply-and-fit job but with a smaller invoice.

Run the honest total. Add the survey, the fitter, the skip, the access equipment, the sealant, the making good, the time off work and the cost of a mistake. Sometimes supply-only still wins. Often, once you price the headaches, the gap closes. The cheaper quote has not lied to you — it has just stopped at the kerb. Whether that is a bargain depends on how much of the rest you are willing to carry.