It had still not sold 11 months later, when Jack Dodsworth, a Teesside developer, snapped it up for £160,000. He has since saved the stone tower and built a family house onto the side. The four-bedroom property is on the market for £435,000 — although after three months it has yet to receive an offer.

“It’s a beautiful building,” says Dodsworth, who went £10,000 over budget on the restoration. “But the roof and windows had fallen inwards. We saved it.”

Others buyers are looking for a lifestyle change or a new home in the wilds of a national park or, in Perlin Dobson’s case, the Scottish Highlands.

Dobson, 43, and her extended family — three generations of 10 adults and seven children — left Nottingham to embark on a new life in Scotland after they bought Duncraig Castle for £715,000. Their renovation of the C-listed castle, featured in July 2002 for £450,000, became the subject of a BBC documentary, The Dobsons of Duncraig.

Since the programme aired in 2004, Dobson and her husband Sam, 40, have bought out their in-laws, and are the castle’s sole owners. Their dream was to turn the 80-room Victorian house into a private members’ club, but after spending £1m, Perlin, a former social worker and Sam, a builder, have had to settle on letting out three suites through their website, www. duncraigcastle.com, to bring in income.

“There have been days when I’ve thought I can’t go on,” says Dobson, “when we’ve run out of money and we’re just exhausted.”

Others who bagged “bargains” are still embroiled in the planning process, unable to touch their properties, let alone sink a borehole or dig a septic tank, until they obtain the right paperwork.

A handful of projects, though, have proved so daunting that they have either been withdrawn from sale or are still waiting for optimistic and seasoned DIYers up to the task.

The rather dour St Kentigerns Church in Grinsdale, Cumbria, featured in March this year, which has a graveyard rather than garden, is still for sale. The vendors are prepared to entertain any offers for the property, which would make a one-bed home, but only once planning permission has been obtained to convert it to residential use.

So, too, is Nimrods, a barn set in 75 acres near Badminton, Gloucestershire, with planning permission for conversion to a family home, which first went on sale in April with a price tag of £895,000. It has been put back on the market with just 10 acres, and a reduced guide price of £650,000.

New Water Haugh cottage in the Northumberland national park has been languishing on the market even longer. Featured in September 2004, the two-bed property by the River Tweed will be sold on a 15-year lease, at a peppercorn rent of £1.

In return, the tenant has to spend £65,000, completely renovate it and install mains electricity. When the lease expires, the property reverts to the estate — a charitable trust — and the tenant can walk away or pay the market rent.

So is it worth following in the footsteps of Swailes, Bevan, Dodsworth and all the others? The climate has certainly changed since the heady days of 2001, when the craze for renovating former agricultural properties was at its height and hundreds of feverish buyers would regularly crowd into pubs and village halls across the country to bid for barns.

Property prices at the time were rising by double-digit percentages across the country, virtually guaranteeing profits however serious the cost overruns.

Buyers today do not have it so easy. Prices are growing more modestly, the number of tumbledown cottages and derelict properties for sale is going down and building costs are going up — all of which cuts into potential profits.

The prices of projects in Devon and Cornwall, for example, have risen particularly steeply, obliging those in search of bargains to head to less fashionable areas such as the Welsh borders or, like Swailes, Northumberland to invest.

“You can no longer rely on a steeply rising market,” says Liam Bailey, head of residential research at Knight Frank. “But if you are fairly canny and keep tight control of costs, then you could, absolutely, still make money restoring your dream home.

“But you’ve got to be in the right place at the right time. It is a lot of work, and there is an element of luck as well.”

• The Windmill at Ferryhill is for sale with George F White, 01388 527 966, www.georgefwhite.co.uk

Explore Property

• Buying & Selling

• New Homes

• Overseas

• Interiors

• Investment

• Gardens

• Cool In Your Code

• Specials

• First-time buyer

Times recommends

• Second homes: credit crunch casualty or money-spinner?
• How I built my own sliding house
• Top 10 incentives for house buyers