Their initial idea was to create a flat above, so they interviewed four architects, but it was clear from the minute they met Paul Archer (paularcherdesign.co.uk) that he was the one. "I have little visual imagination, but Frank does," said Maria. "Frank knew what he wanted and Paul just got it."
"I always wanted to do a development project," Frank said, "but never thought it would be possible in London."
Archer did some drawings, but then Frank got a contract that took the couple to Salisbury for a year. Then, instead of going back to Finsbury Park, they rented a flat in St Margarets in Twickenham, to see if they liked the area better than Finsbury Park. They did, and they also liked what they were experiencing in their rented home — clean wooden floors and under-floor heating were a revelation. So they put their period house on the market and started looking.
Their "musts" list was short: three bedrooms, proximity to public transport, and a small garden. "We wanted to downsize our space but upscale our quality of life," said Maria, who is self employed.
But then, as she put it, "the story diverts, because I wasn't looking for a building site — but Frank clearly was".
They saw a Victorian house in Teddington, near the station, in a stepped terrace, with a small garden. The owners had lived there for 42 years and "it had been bashed about", Maria said.
Frank joined in: "I saw the potential straightaway. We were talking about major works just to sort things out despite the agent claiming that all it needed was a coat of paint. It was on the market for £550,000 and we got it for £465,000, in 2010." The house was dark. "With a poky front room, a poky back room, an old Sixties kitchen and an overgrown garden with a stagnant pool. The only thing holding the stairs up was the stair carpet," said Frank.
Next, the couple called in Archer. In response to their main idea of getting as much light as possible into the property, he came up with an audacious solution. He suggested taking out all the original supporting brick outside walls and replacing them with folding glass doors.
In engineering terms, this meant excavating six feet down to lay a massive slab of concrete to support the steels needed to hold everything up. But the genius part of this radical transformation is that the couple didn't change the footprint of the house at all, so didn't need planning permission. "We didn't need more space, we needed better space," said Maria. "The only original thing left is the roof — oh, and the front." So, from the demure Victorian exterior, one walks into a magazine house. The effect is clean and sleek, welcoming, quiet and warm.
All the floors are engineered walnut, which is silky and cosy underfoot. Dividing doors have been replaced with full-height sliding pocket doors, or removed altogether. The old staircase went out and a slimmer one, in walnut, went up instead, top-lit by a skylight, with a full-height glass wall separating it from the living area.
The kitchen, in the centre of the house, is integral to the long, flowing, ground floor space. From any part — from the old front room, to the central kitchen/ living area, to the relaxed seated area near the garden — one can see the outdoors through the new glass "envelope", which creates a tremendous sense of freshness and serenity.
Upstairs, the couple continued the sleekness theme. The front master bedroom boasts a narrow floor-to-ceiling sliding door that leads into a Pandora's box of a bespoke walnut dressing room, which leads in turn to a marble-walled bathroom, divided rather sexily from the dressing room by a sandblasted glass wall.
This is a house full of grown-up style. Yet amazingly, the complete transformation, including fittings, was done for less than £200,000.
A big money-saving trick was having the kitchen fronts made by the builder, in powder-coated MDF with white Corian tops, put on Ikea carcasses. Recessed ceiling lights are the same style throughout; door-handles and fittings are simple brushed steel, and the Duravit double bathroom sink, Maria said, was surprisingly inexpensive.
As she contemplated the garden, with its mature Japanese Acer tree, she said: "We wanted an outside room — not to be bothered with mowing a lawn." She added: "I wouldn't want to move ever again. I want to stay here."
Get the spec:
* Architect: paularcherdesign.co.uk
* Cost of house in 2010 £465,000
* Transformation cost: under £200,000
* Completed: 2011
* Worktops: corian.co.uk
* Bathroom basin: duravit.co.uk
* Ikea: ikea.com
* Engineered walnut flooring: thesolidwoodflooringcompany.com
* Folding doors: sunparadise.co.uk
* Joinery: matthew elton.com
All photographs by Nick Guttridge