New kitchen: from the old units out to the last plinth

Units and doors are usually the largest single item, but they are only part of the total. Worktops, appliances, sink and taps, lighting, flooring, splashbacks, electrical and plumbing work, plastering, decoration and fitting labour all add up. Which? price research for a twelve-unit kitchen found large differences between brands for the cabinets alone, before any worktop, sink, taps or appliances, and it estimates that fitting labour makes up a substantial share of the final spend if you do none of the installation yourself.

The layout drives cost as much as the brand. Keeping the sink, hob and oven where they are avoids moving water, waste, gas and circuits. An island with a hob or sink needs services brought through the floor, and a tall run of ovens may need its own circuit.

The design is usually agreed first, then a final survey measures the room once any walls, windows or doors are in their final positions. Units and appliances are ordered, and delivery can take several weeks. The fit itself follows the usual sequence: strip-out, first fix of plumbing and electrics, making good plaster, flooring where it runs under the units, carcasses, worktops, then second fix and finishing.

Stone and quartz worktops add a pause, because they are templated once the base units are fixed and then made to measure. Plan how you will cook and wash up for the weeks without a working kitchen, and ask for the dates on paper.

• the drawing number or version the order is based on
• delivery date and who checks the delivery against the order
• the start date and the planned days without sink and cooker
• worktop templating and fitting dates
• when the gas and electrical work happen and by whom
• what is left for you: decorating, tiling, flooring, disposal

Anyone employed to work on gas appliances or pipework in a home must be on the Gas Safe Register and competent for that type of work; the categories are listed on the back of the engineer's ID card. That applies to disconnecting an old gas hob or cooker as much as to connecting a new one.

A new kitchen is not a special location for electrical work in England, but new circuits, such as a dedicated circuit for an induction hob or a double oven, and a new consumer unit are notifiable. Installing a built-in cooker on an existing cooker circuit is not. A registered electrician can self-certify notifiable work.

Approved Document F asks for a kitchen extract rate of at least 30 litres per second where a cooker hood extracts to the outside, and 60 litres per second where there is no hood or the hood recirculates. An existing extractor has to be kept or replaced during refurbishment. A recirculating hood is often chosen for an island, but it does not remove moisture, so ask how the design deals with that.

Kitchens are commonly sold with a deposit and staged payments. Keep payments in step with delivery and work done, and avoid paying the final balance before snagging is complete. Paying by credit card can give extra protection under section 75 of the Consumer Credit Act for purchases in the qualifying price range. If you sign at home, a cooling-off period usually applies, but goods made to your specifications may be excluded, so read the cancellation terms first.

Ask who is responsible if something arrives damaged or missing, and who pays for the fitter's lost day if a cabinet has to be reordered. On a design-supply-fit contract, that is usually the kitchen company.

Lifting an old floor can reveal thermoplastic or vinyl floor tiles and adhesives which, in older buildings, may contain asbestos; the Health and Safety Executive lists these among the places asbestos is found. A careful company arranges a test before breaking them up. Old wiring or lead pipework may also turn up once the units are off, so ask how extra work would be priced before you sign.

Tell us the room size, what should change and roughly when, and confirm your phone number and email address. Kitchen companies nearby see the request without your contact details. One company can buy it, and the request then disappears from the list. Before that company sees your details, we email you its name, address and phone number. You pay nothing, there is no guarantee any company takes the request, and it is withdrawn after 21 days if unsold. We check that buyers are registered businesses, not the kitchens they fit.