Supply only vs supplied and fitted

Supply only means we make the product to your sizes and deliver it. You, or a fitter you appoint, take it from there. Supplied and fitted means we do the lot and hand you a finished opening.

The saving on supply only is real — you are not paying for a survey, a fitting team, their van, their scaffolding or the certification. On a whole-house window order that difference is substantial. But you are also taking on four things that the fitted price normally absorbs, and it is worth being honest about all four before you decide.

What you take on

The measurements. This is the big one. On a supply-only order, the sizes are yours. If a frame arrives 15mm too wide, that is a remake, and a remake is not a warranty claim. Measure the structural opening, measure it in three places, and use the smallest number.

Building regulations. Replacement windows and external doors are notifiable work. On a fitted job the installer self-certifies through FENSA or CERTASS and the certificate lands on your doormat. On a supply-only job there is no registered installer involved, so you have to notify building control yourself and pay their fee. Do not skip this — it surfaces when you sell.

Waste and making good. The old frames have to go somewhere, and there is almost always plaster, render or brickwork to make good around a new frame.

The lifting. A four-pane bi-fold or a 2m rooflight is a two or three person lift, and it is glass.

When supply only makes sense

You already have a builder on site. You are doing an extension and the opening does not exist yet, so there is nothing to survey. You are a competent DIYer replacing a single door. You are in the trade. In all four cases you are paying us for the thing, not for the labour you already have.

When it does not

A single window in a Victorian house with a rotten timber sub-frame is not the job to learn on. Anything at height. Anything structural. Anything where a mistake costs more than the fitting would have. In those cases take the fitting — it is available on any order and it is priced separately, so you can see exactly what you are paying for.