Building a swimming pool in the garden will cost upwards of £25,000 and might not be recouped in the asking price, according to Knight Frank estate agents.

While Britain?s appetite for home improvements is on the rise thanks to inspiring home make-over programmes, the cost of the project may not always be fully recouped. While some work such as installing central heating and refurbishing the kitchen is likely to add value to the property other projects such as changing the windows, building a swimming pool and renovating the basement will have only a minor impact on the value of the property.

?While many home improvements can certainly add to the sale-ability of a property, the cost of the project won?t necessarily add to the asking price,? cautions Knight Frank Partner, Tom Tangney.

?Home improvements must also be appropriate to the market: a deck is going to be a desirable feature in Clapham but may look out of place in parts of Chelsea. A Smallbone kitchen will definitely be worth the cost for a house in St. John?s Wood but you?re unlikely to re-coup the cost in Hackney. Most importantly, a bad DIY project will always detract from the re-sale value.?

Project | Cost | Average payback

Adding central heating | circa £5,000 | 100%

Minor kitchen refurbishment | £3,000 – £5,500 | 95%

Major kitchen refurbishment | £10,000 – £30,000 | 95%

Add en-suite bathroom | £10,000 – £15,000 | 92%

Refurbish bathroom | £5,000 – £10,000 | 77%

Add fireplace | £1,500 – £3,000 | 75%

Build deck/roof terrace | £5,000 – £10,000 | 73%

Replace windows | £15,000 – £20,000 | 65%

Renovate garden | £2,000 – £15,000 | 30% – 60%

Install swimming pool | £25,000 and up | 44%

Finish basement | £70,000 and up | 15%