Cheap land prices and the recession mean that more and more people are donning hard hats and opting to self-build their own houses

When Glyn and Jane Martin decided to convert a wooden shack on the Devon coast – complete with spiders, mice and rampaging ivy – into a more permanent home, it is safe to say they did not envisage exactly how it would impact on their lives. The first stage was to commission a design from their architect daughter Annie; this agreed, builders were called in to lay the foundations. Then the family took over – Annie and her partner Mark, a carpenter, moved on site to supervise the project; Glyn and Jane bought a caravan so they could join them, and Jane took a year out from her job as a teacher. New skills were learned (plasterboarding, tanking the blockwork), but work progressed more slowly than expected, particularly in winter when the weather could be, as Annie says euphemistically, "quite wild".

"It was a dream we wanted to realise, so we just went for it," says Jane of the two-year period. "Of course there are times when you are working in a blizzard and you know the next delivery is coming and you don't know where to put it. And you think: 'Whose idea was this?' But we could always stand back and say, 'Look what we've done. Look what we're achieving.'"

What they have achieved is certainly spectacular. The Seacombe residence is a spacious, luxurious two-storey house with impeccable eco credentials. It also has total wi-fi coverage, a state-of-the-art kitchen and a secret cinema hidden behind a bookcase. And the hard work has more than paid off: the land costs were £300,000, building was £350,000, but the property is now valued at £1.2m.

There's always been a small band of intrepid BYO (build your own) pioneers prepared to don hard hats and construct their own castles – saving thousands in the process – but their numbers are on the up. And the recession is helping. Plot prices are down 20% on last year (and 33% since January 2008), according to BuildStore, the largest one-stop shop for self-builders. Additionally, small builders who have traditionally snapped up such "windfall" sites have had their financial plug pulled by banks less inclined to dole out cash, leaving the door open to those who want to do it themselves.

"If you've had a long-term dream to build, now is probably the best opportunity for 10 or 15 years," says Michael Holmes, editor in chief of Homebuilding & Renovating magazine. Holmes, who has both renovated and built from scratch, has found building much easier, and if you're handy and you've got the time – most self-builders are self-employed, retired or able to take time off work – it's definitely worth it.

"It is a time commitment," says Holmes, "but you get a bespoke house and you end up with a property worth considerably more than it cost. You are building in equity. You are building in a profit margin. For people who are climbing the housing ladder, it's a fantastic way of actually making it happen. And it's tax free."

Monty Ravenscroft became a self-build sensation overnight, when he showed what could be done with an unprepossessing scrap of urban wasteland in south London. Armed with a tiny budget, a pile of books, a gang of mates and impressive derring-do he transformed a narrow, derelict plot into an open-plan, cutting-edge family home – his antics closely followed by Grand Designs. And the nation loved him for it: "It was a David and Goliath thing," says Ravenscroft, who works as an engineer, actor and film producer. "We were struggling against the system, as self-build mortgages all catered for the standard process, for a standard house with a standard value. Which ours had none of. We were going to use weird materials, in a weird site, with a weird design without any windows." The skinny strip of land was cheap at £40,000, because windows were not an option – his neighbours are too close – but, after 18 months of hard work and a spend of £170,000, the house was valued at between £600,000 and £700,000 in 2006.

But it's not all about saving cash. Boxy Victorian terraces, for one, are constricting, and knock down as many walls as you like, there's a limit to what can be done with them. Self-builders, on the other hand, have the luxury of living in a tailor-made space, and they know what they want. "Large entertaining spaces, a kitchen breakfast room, glass doors opening out on to the garden, under-floor heating… These are all the basics that go into self-builds now," says Holmes.

In 2009 there was a 145% jump in the number of plots sold between the first and third quarter, according to BuildStore, and of all new detached houses at least a third are estimated to be self-build projects. It's no wonder television shows such as Grand Designs pull in the crowds. As for those contemplating taking the plunge, top tips include: don't pay up front for work; don't get disillusioned in your hunt for a plot; do your research; set your budget; project manage yourself; claim back VAT on all your materials; and when you're up against it and feeling the strain, keep an eye on the bigger picture.

For Ravenscroft the pressure peaked on concrete days: "I hate concrete," he says. "Stress levels are very high because you are spending a lot of money. The trucks are arriving, the pumps are arriving, the people are arriving. You start pumping and things start going wrong, and you can't do it, and you can't finish, and meanwhile it's setting behind you… It's just really miserable." Even on good days, he says, the construction process is still all-consuming: "You are looking at it. You are thinking about it, you are dreaming about it and you are having nightmares about it, because it takes up every moment of your life. But then you end up living in what some people say is paradise."

Ian and Sarah Gluyas, Oxfordshire

Ian and Sarah wanted one extra bedroom for them and their three children, but couldn't afford the financial hike needed to move from their three-bed. Instead, after scouting around for almost three years, they found a plot for £120,000 in their Oxfordshire village, sold their house and moved into a caravan on their new piece of land (living in situ reduces your site insurance).

"I paid for it to be a water-tight shell and for an electrician," says Ian. "But I did the plastering, painting, fitted the bathrooms, a bit of plumbing, tiling, hanging doors, the carpentry…" A Formula 1 engineer, but a boat builder by trade, Ian was working five days a week and 17 weekends that year, but somehow made the time needed to complete the house within 18 months. "I would start at 8pm after work and go through until 2am."

With Sarah as on-site manager and fellow painter, they put in a £30,000 kitchen for just £6,500, and after a total building spend of £125,000, they had the house valued at £450,000. The other good thing about being a self-builder, Ian points out, is that you can keep tweaking and adding little extras; he is now building a bespoke car port for £6,000 – saving nearly £30,000.

Donald and Catherine Bisset, Peeblesshire

Donald and his wife Catherine were looking for a bigger place for themselves and their first child, only to find they were priced out of the ready-build market. They casually started looking for plots and came across one on the River Lyne, 30 minutes from Edinburgh, which they felt they had to grab. It was in their budget and came with detailed planning permission for a five-bedroom house.

In between abseiling off oil rigs in the North Sea where he works as an inspector, Donald set himself the task of building a large family home from scratch, learning all the trades as he went along. With a stack of books and the help of knowledgeable friends and family, the Bissets took nine months to complete their new home. Donald, who had previous experience with various roofing jobs, dug the foundations in apocalyptic conditions, built the timber frame and did the roofing and the plumbing. He pushed himself so hard he came down with pneumonia.

The Bissets believe they have found the perfect location for their family and, having paid £165,000 for the land and a further £150,000 for building costs, they have recently had the house valued at £400,000.

Brad Lochore, East London

In 2005 conceptual artist Brad Lochore decided to overhaul a Victorian warehouse he had bought in Shoreditch in east London in 1996 for £120,000, and turn it into a contemporary studio and living space. He employed Tony Fretton Architects to design the space and building, but quickly became disillusioned with the builders he called in to price up the job.

"The contractors either came back and said: 'We can't do it we're so busy', or they came back with such ludicrous prices, so the only option left to me was to roll up my sleeves and do it myself." Being self-employed left Lochore free to manage his time, and as an artist he had a basic understanding of materials. He spent £280,000 on the rebuild, plus £30,000 for extra land from his neighbour. He believes he saved a couple of hundred thousand by doing the work himself, and has since had an informal valuation of £3m.

Lochore has ended up with a building with two to five bedrooms (depending on what rooms are being used for), two bathrooms and three kitchens. "I've produced a unique, beautiful building," he says. "I know every single nut and bolt in it."