For the cost of 10 lottery tickets, you get professional feedback, the architect gets to work indoors, and the dough goes to Shelter, the charity for the homeless. You simultaneously promote several good causes, not least your own.
Architect Week, which is held in November, features exhibitions and events nationwide. Last year, more than 1,200 practices throughout the UK took part in Architect in the House, and the donations to Shelter amounted to more than pounds 13,000.
More than a 1,000 homeowners exploited the scheme, including Chris and Ding Jenkins, who bought their three-bedroom first-floor maisonette in Mortlake shortly before the birth of their first child, Ethan, two years ago.
In the course of 90 minutes, local architect Tzena James suggested effective ways of dealing with dull floorboards, cracked plaster, a rickety garden stairway, and numerous other items. The Jenkins got 10 quid's worth of advice within the first five seconds, and the rest was gravy.
One problem, however, proved intractable. Their kitchen is small and, worse, is next to the flat's only lavatory and, worse still, kitchen and bathroom each open directly into the compact dining room. Initially, the Jenkins thought that, although expensive, building an en suite bedroom in the loft was doubly attractive: they could remove the lavatory from the kitchen area and expand the kitchen into the liberated space.
"Local estate agents deterred us," Mr Jenkins explains. "They advised us that when we came to sell the flat, we would need a first-floor bathroom anyway." With Tzena James they discussed several options for moving the bathroom to another first-floor location. The best solution, which entailed moving it to the far end of the dining room, was one to which no one really warmed.
Other homeowners who took advantage of Architect in the House confirm that tight space is a near-universal problem. A couple with four young children recently bought a three-bedroom house in Essex and have pounds 40,000 to eke out more space. But Potters Bar-based architect John Chandler broke the news that "after VAT and incidentals, they really have less than pounds 35,000. And they can't decide between a loft conversion or a room extension as they don't know how long they will stay."
Mr Chandler also visited a Cheshunt couple with two sons and one room extension who wanted a second extension: "Instead of a separate additional room, I showed them how they could build over the current extension and rearrange the existing rooms," he says.
Another couple in Hertfordshire wanted some peace after giving a room to each of their two teenage sons. They also wanted the darker, colder end of their house to be brighter. "We came up with a range of solutions using pyramidal glass in the kitchen which allowed room on one side for a self-contained flat for their sons," says Cambridge-based Jonathan Ellis- Miller.
He also advised homeowners in King's Lynn, Norfolk, whose 19th-century listed mill had been refurbished in the Sixties, and looked it. The owners wanted professional advice to ensure a truly Victorian renovation. Architect David Natas of the Culpin Partnership in Richmond, saw one homeowner whose children were soon to leave the nest, and another with recent fledglings. The former "intended to split the property into three separate dwellings to let, and she had sorted out the spatial requirements," says Mr Natas. "But her plans contravened building regulations, and she might need a feasibility study and a basic set of drawings to get funding." He also notes that architectural drawings "should also reveal whether her plans could realise the kind of rental income she envisaged".
The second occupiers were a retired couple "who decided to install central heating, and wanted an architect to manage the project and ensure that the installation of the pipework didn't ruin the original Edwardian features," he reports.
Many architects are available for between pounds 35 and pounds 50 per hour, and because they are not essential in the way that plumbers or electricians usually are, many homeowners begrudge what appears to be an unnecessary extra expense.
For many owners, though, the savings are false, aesthetically as well as economically. Architects can ensure that the building and decoration budget is well spent, and their advice sometimes leads to savings which more than recoup their fees.
Mr Chandler advised one client that their idea for a loft "did not represent a good return in terms of price per square foot".
Many homeowners skimp on design advice, commission a builder directly, and then have to live with the mediocrity that they have paid for. One family involved in this scheme had purchased two large, high-back sofas shortly before the architect's visit. The sofas overwhelmed the room and the high-back design was contrary to what their low windows cried out for. A different sofa and an armchair would have been more appropriate for the individual setting.
For the Jenkins, the home visit had a delayed benefit. After mulling over Ms James' words for a few days, they decided that it was better to ditch the estate agent's advice, convert the loft as originally planned, and enjoy an enlarged kitchen in a loo-free zone.
Architects bring in the light to your home and let you see things in an entirely new way. This year, it could be you.
This year's Architect Week is in November. Contacts: Royal Institute of British Architects, 0171-580 5533; John Chandler, 01707 875904; Culpin Partnership, 0181-948 4281; Ellis-Miller Architects, 01223 362648; Tzena James, 0181-940 4068Reuse content