The problem is all the more acute if the business employs staff, or if there are deliveries or visitors. At best, the result is cramped chaos; at worst, there are neighbour complaints and uninvited visit by local planning department officials.
Even so, live/work apartments are a happy alternative to the expense and inconvenience of renting a separate office or studio. Physically, a live/work apartment can be identical to a normal, residential flat. The difference is that the flat is sold for combined business and residential use - and has planning permission for both.
Live/work developments are successful because everyone knows where they stand. There are thousands of people who work from home every day in spare bedrooms, loft conversions or basements and no-one knows. If the business use is little more than a desk and a computer, the authorities are not going to be concerned. But for larger, noisier, busier undertakings, live/work spaces get round the potential nuisance of running a business in a residential area.
Image is a factor, too. Some small companies want a business address, especially if clients visit. A slick city-centre loft or apartment is a better meeting place than a kitchen table in the 'burbs. "You can have a bona-fide business address," says Philip Jackson, residential sales manager at agents Stirling Ackroyd, which specialises in live/work space in London. "You can have business deliveries or despatch riders and no- one can complain. You can legitimately have people visiting the office."
Most early live/work developments were on the fringes of the City of London and that is where most of them are still built. The first wave of live/workers rented, rather than owned, their homes. They took leases on large, cheap office and warehouse space in areas like Clerkenwell, Shoreditch and Hoxton. Pioneers included artists, designers and photographers who needed space. Working and living under the same roof saved on costs, and meant creativity was not constrained by office hours.
Brad Lochure bought his former printworks in Shoreditch, East London in 1996. An artist, Brad had rented studio space in West London but found the short-term leases disruptive. It took some time to find a suitable building: he needed natural light, combined with ground-floor access to load his large canvasses. "This place has been absolutely fantastic," he says. "I can come down at 1am and do an hour's work without leaving the front door. Plus there is a ready-made community of artists here, and a lot of them happen to be my friends."
Developments like Brad's have proved successful but success has brought its problems. Many live/work developments were "without ratio". The buyer could decide how much - or how little - space he/she wanted to use for work. The result was an influx of professional people who had little or no intention of using their space for business.
In response, planners are becoming more cautious, and they may insist that as much as half the floor space is used for business. In some cases, this means the ground floor is an office or studio space, with the flat above: effectively, a return to "living above the shop".
Now live/work developments are slowly spreading out of London. In Leeds, the city council is encouraging live/work space in areas like Holbeck; developer Urban Splash hopes to start a scheme in Manchester next year. The most advanced project is in Sheffield, where Gleeson Homes plans to include live/work space in its Cornish Place project, a former cutlery factory. "We are converting the building into a mixture of office, residential and live/work space," explains managing director, Clive Wilding. "In our experience, live/work apartments work best in a mixture of other houses and offices."
Live/work accommodation is becoming more expensive. The areas that pioneered live/work space in London have moved upmarket with property prices in areas such as Clerkenwell rising sharply in the past year. Live/workers are looking further afield, to Southwark or Tower Hamlets for space, while developers are taking on sites in more conventional, residential areas. In Fulham, Stonehurst Estates has built "atelier" apartments, each with office and flat, on the site of an old bakery. Most have been sold, with prices starting at pounds 265,000.
Purchase price is not the only cost with live-work apartments. Buying one means paying business rates on the work area and possibly VAT too. There may be capital gains tax to pay on the work area when it comes to selling up. Despite this, live/work space holds its value well. According to David Salvi, a partner in London agency Hurford, Salvi, Carr, live/work space now sells for the same price as residential flats.
"The flexibility of a property with one of two uses has to be more valuable than straight office or residential space," he explains. "As live/work grows and more people work from home, they could even sell at a premium above residential space." It could be one case where mixing business and pleasure does pay.