The couple worked in the West End and had to travel two hours every day to reach work from their north London house. Like so many parents they only saw Mimi and Ella, 10, at the start and end of the day. Abigail says she could not even enjoy small pleasures such as taking the girls to school.
The pair, both architects, bought their three-bedroom Victorian property in Bush Hill Park, Enfield, 20 years ago, but had since set up their own practice (ashtonporter.com), renting an expensive London office. After nearly 15 years they'd had enough and decided to address their unsatisfactory live/work balance.
The award-winning solution lay at the bottom of the garden, in two tumbledown sheds that they knocked down and transformed into a home office smart enough to wow potential clients. And in keeping with the supercool office they transformed the rest of the garden, too.
The cost of the project totalled about £120,000 but savings on central London rent meant their debt would be paid in two to three years. Being architects, they knew planning permission rules and procedures and how much they could undertake without having to go through too much paperwork.
Andrew, 46, says: "We did not want to cut corners or quality. This building is our showcase." But building was slow. They began in 2005 and completed in 2010, carrying out a lot of the labour themselves.
But the result was life-changing, plus they won the annual Don't Move, Improve Award from New London Architecture for the most innovative home extension project. "We have changed the way the house works, so we live in the whole plot efficiently now with the garden as a corridor between home and work."
At the time, planning rules allowed them to demolish the sheds and build a three metre-high, flat-roofed studio — with a metre's gap between its wall and the boundary with their neighbours — without planning permission. These rules have now been tightened a little, but you can still build a 2.5metre-high garden room (measured to the level of the eaves) so long as a two-metre gap is left.
And as the studio is a shade under 30 square metres, they also did not need to apply for building regulations approval for the project. In fact, its quality exceeds building regulations.
THE TOUGH BIT
The first job was to dig a 25-metre trench from the house to lay down pipes and cables to supply the studio with water, gas, electricity and computer wiring. Then a concrete slab was poured on to the site to act as a foundation.
The couple wanted their workspace to "disappear" into the garden — after all, who wants to see their office at the weekend?
So they chose to clad the façade in "cheap as chips" wooden batons that give the effect of a garden fence. Behind that is a layer of glass. And since the batons don't reach quite to floor level, the studio appears to float above the garden, an effect enhanced when the lights are on at night and the building appears to hover on a bed of light.
From inside the studio the view over the garden is partly obscured by the slats — though the building gains light from a large skylight, which can be opened for ventilation.
The roof of the studio is sedum, so the view from the top floor of the house is an expanse of plants. The sides and back are clad in utilitarian corrugated aluminium, and underfloor heating goes on in winter, though, thanks to good insulation, the couple say they usually don't need it.
The studio is large enough for a good-size office, bathroom, and even a tiny kitchenette. They were able to avoid the need to obtain permission to use the space for their business partly because they also use it as a family room for the twins to play in and do homework.
The garden space is divided into two distinct zones: a conventional paved area closest to the house has room for a dining table and plenty of chunky plant pots, while the rest is decked with a rectangular fish pond cut into it.
But the biggest innovation is a series of trapdoors cut into the wood, concealing a heated paddling pool, a sand pit, and a fire pit, as well as space for the pond filter.
"We thought that it was such a waste of space to have a deck and have all that space underneath it. We chose to make the garden as much of a playground as possible, but you could equally well have storage," says Abigail, 45.
When the trap doors are shut, the deck space is huge — great for games or for entertaining — and the final surprise of the garden is a little joke: a circular patch of grass, also cut into the deck, as a tribute to conventional suburban lawns.
Finally, the couple decided to swap their house layout around, putting the kitchen at the centre and the dining room at the back.
The enlarged kitchen now leads into a new dining room with a wall of bookshelves and a wall of cupboards a metre deep.
The studio cost £60,000 and the garden landscaping about £20,000. Works to the kitchen and dining room cost £40,000. Will they make their money back? According to the Labour Force Survey, in 2009 there were 691,000 British home workers, compared with 582,000 in 2006. Andrew says: "We did it for family gain, not financial gain, but I am certain that with so many professional people working from home now, this well-designed office space will make financial sense, too."
Photographs: Simon Maxwell