House renovation cost

Checkatrade's breakdown for a typical three bedroom house adds up to £43,530 to £110,350, with an average of £76,690, and the table is marked "+VAT". MyBuilder says a full renovation typically starts at around £43,500 and puts a typical three bedroom house at £43,500 to £180,000 or more. The Federation of Master Builders (FMB) says the average homeowner spend on a renovation over the past five years was around £52,000.

Only MyBuilder gives a figure per square metre, at £650 to £2,800 per m², with basic cosmetic updates at around £650 per m² and a full internal strip out and refit at £650 to £2,000 per m². No source gives renovation prices for Sussex specifically. The gap between the lowest and highest figures reflects how differently a light refresh and a full structural renovation are priced, so start by deciding which jobs your house actually needs.

Rewiring and replastering are usually done together in a full renovation, because new cables are chased into walls that then need making good. The sources give quite different figures, partly because they define the job differently. Checkatrade's £10,000 to £15,000 to replaster the walls of a three bedroom house sits well above MyJobQuote's £3,500 to £5,500 for a three bed semi, so they appear in separate rows rather than being combined.

MyJobQuote says a full rewire will usually include labour and materials, and that most plastering quotes include labour and materials but exclude scaffolding, decorating and rubble removal. Checkatrade says a full rewire takes 6 to 15 days. GOV.UK lists replacing the fuse box and connected electrics among the alterations that may need building regulations approval, although you do not need to get approval yourself if you use an electrician registered with a competent person scheme.

Older houses often reveal problems once floors are lifted and plaster is removed, which is why most sources recommend a contingency. Checkatrade suggests 10 to 15%, MyBuilder suggests 10% to 20%, and Homebuilding and Renovating's extension guide advises at least 10% plus a further 5% for inflation. Set the contingency aside from the start rather than spending it on upgrades.

Professional fees are also extra on larger renovations. MyJobQuote puts architect fees for renovation projects at £2,000 to £7,500 or more, and Homebuilding and Renovating gives 2 to 5% of the build cost for a CIAT architectural technologist. Building control charges vary by council, so check your own council's building control page, or ask a private registered building control approver, which sets its own fee.

Write a room by room list of what you want done before asking for prices, and give the same list to every builder. Ask for an itemised quote that separates the electrics, plumbing and heating, plastering, joinery, kitchen, bathroom and decoration, and that says clearly what is excluded. Check whether VAT is included, who is arranging building control and any certificates, how the work will be staged and paid for, and how the builder will price any extra work found once the job starts.

Comparing several detailed quotes is the best way to see where your house sits within the wide published ranges. Through Sussex Builder you can get up to 3 free quotes from checked local builders, with no obligation, by using our renovations page or calling 01273 115520. If your plans include adding space, our loft conversion cost guide covers the other common way to enlarge a home.