When Sam Adams and Valerie Blair moved into a semi-derelict warehouse on the top floor of a former clothing factory, the windows were boarded up, pigeon poo caked the floor and it was bitterly cold. Instead of a number, it said "Stalbow Fashions" on the door. "It was in pretty raw state," says Adams, 33, an artist. The couple scrubbed and painted the floor and walls, and vacuumed up a decade's worth of sewing machine needles, fallen between the floorboards. To keep warm, they huddled round a camping stove, drinking cups of tea with their coats on. The upside? Eye-wateringly cheap rent for a spectacular location. Blair and Adams were "property guardians" of this 2,000 square-feet, east London loft, a stone's throw from the glass offices of Bishopsgate, in the City of London – living there temporarily, at low cost, to prevent the building from falling into further disrepair, until it was developed. They paid £160 a week in rent. "We were really drawn to a raw space we could be creative with," says Blair, 29, who works for an art gallery. "And it was a great price." The loft was four times larger than the couple's previous home, a tiny ex-council flat, and half the price. It had stood empty for nearly a decade before they moved in. "It would have been tempting to fill it with furniture, but we kept it quite sparse," Adams says. "And it meant we could take it all with us when we moved out." The look, borne out of necessity, was pure pared-down vintage: a G Plan sideboard, a huddle of secondhand armchairs and a large dining table constructed from two Ikea trestles and reclaimed wood. To combat the cold (there was no heating), Adams built a small cube with a door and window, which is where they slept: "Our indoor igloo." The kitchen had a fridge, water heater, cupboards and two cooking rings. Blair converted a large storeroom into a walk-in wardrobe of which Carrie Bradshaw would be proud. "That was my priority," she says. One of the biggest challenges was the light. "It was so bright, particularly in summer. We had no curtains, so woke up with the sun as it reflected off buildings nearby." The building had five flats, all occupied by friends of the pair – live-in guardians, too. They often ate together, and Adams and Blair shared a shower with the couple below. "There was a family feel to living there," Adams says. It meant the terrible soundproofing and general decay became less of an issue. Gaps between the floorboards inches wide were a hazard: "I once spilled a splash of water on the floor and it dripped through not just to the flat below, but the one below that." Was it hard adapting to such an unfinished space? "You stopped noticing the lack of frills, such as an oven, and realised what you never really used," Adams says. "We only really cooked on a hob anyway. It allowed us a different style of living – we didn't go out as much, but had friends round all the time. It changed my attitude to buildings, too. I now look at all sorts of places and think, could I live there?" "It was hard having less privacy," says Blair. "And I missed having a bath, and a certain level of finish. But it was an adventure – it felt like real loft living, and I learned a lot about myself, and what my limits are. I'd never live in a small flat again." The couple found the property through Live-In Guardians, which finds young, professional tenants for empty, usually commercial buildings. The scheme is short-term, says founder Arthur Duke. "Our tenants occupy spaces while the owners are seeking planning permission, and are usually there for around six to eight months." This insecurity is the payoff. Adams and Blair's contract gave them two weeks' notice, and this arrived in the autumn, earlier than expected and at a rather inconvenient time. "It was our busiest time of year work-wise, and we were about to get married," says Adams. Luckily, they could stay with family briefly, and are now bunking down with friends until they plan their next move. Another dilapidated office block? "We'd love to do something similar again," Adams says. "A cheaper tenancy on a strange building. But it will probably be back to the real world."