How to extend a Victorian house in a conservation area: 'hidden' steam-bent timber extension wins over the planners - and adds £600k in value

Securing permission to add a two-storey extension to a Victorian house in a south London conservation area required a lot of imagination - and curved timber.

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Successfully adding a new two-storey section to an old house is a bit like a marriage. So says Ben Perl, 44, who lives with his girlfriend, Amanda Kendrick, 41, in pretty Roehampton village, just beyond East Putney. 

With its steepled church, green, and Victorian Gothic cottages, the village is a setting for a BBC costume drama. It’s a conservation area, too, so the fronts of the houses can’t be altered. Any addition has to be at the back, and if it’s visible from anywhere, the conservation officer must be satisfied that it is in keeping. This meant that the couple’s architect, Simon Gill, had to rethink the look of their double-height, larch-clad extension — and their builders had to learn new skills.

London-born Perl trained as a surveyor. In 2010, living in a flat in Fulham with a former girlfriend, he decided it was time to buy a house. He was a planning consultant by then, and able to ride around London on his scooter to look at contenders. His wish list was clear. “Top price £700,000, a period house with a garden, in a varied terrace in an area with character, charm, and a community feel. But I didn’t mind where in London.” 

He had already seen 40 houses when he spotted the little Roehampton house online. His Putney agent hadn’t shown it to him, thinking he wouldn’t be  interested in the area. Perl booked a viewing. 

A three-storey family home for 25 years, the slate-roofed 1870s house had been extended sideways in the Eighties, absorbing a path. It had also had a “bog-standard” timber conservatory added in the Nineties, which was now leaking and genteelly rotting. Otherwise, the house was largely original inside, with a lawned garden with an apple tree and rose bushes. 

The minute he saw it, Perl knew it would be hard to beat, particularly with green space front and back, and the atmosphere of the area, He bought it, had the old carpets taken up, sanded the floorboards, refurbished the upstairs bathroom, and moved in.

By 2013, now going out with Kendrick, a play therapist, Perl decided it was time to sort out the conservatory. “As well as being rotten, it was boiling in summer, freezing in winter.” He considered rebuilding it. Then putting a proper roof on it. Then he sensibly thought, why not forget all that and put a proper room with another floor on top, holding a bedroom and en suite? After all, the front bedroom was noisy because of the buses that roared past — a problem unknown to Victorians.

Ever pragmatic, Perl called in a planning consultant. Most of us don’t even know they exist. “He saved me thousands,” he says. 

“I described what I wanted, and he considered it from a planning angle, particularly the question of overlooking.” Finding no significant issues, the consultant recommended a few architects, who Perl invited round.

“Simon Gill,” he says, “risked losing the job by telling me what I didn’t want to hear, which was that the newly refurbished upstairs bathroom would have to be ripped out, because it was the only sensible route into the new bedroom.” Instantly impressed, he hired him and gave him “carte blanche”.

Gill did drawings of a two-storey timber-clad, timber extension that flared out at one side to make a bit more room. It would be built on site. On the outside, Gill designed vertical Siberian larch cladding. Larch is a sturdy softwood that weathers well. 

Then the design fell foul of the conservation officer, who insisted that the boards must be horizontal, like old local clapboarded properties. Since Gill had designed an interesting curve on one side, this now meant that the timber would need to be heat-treated to curve round it. No mean feat.

Perl had hired the same builders who had done the now-condemned bathroom. They were brothers, one a skilled joiner. When it came to bending the timbers, something they had never done, Gill sent a handmade steamer “that looked like a long coffin” down from Norfolk, from a boat-building friend. Into the steam went the larch boards, out came pliable wood that had to be quickly curved and fixed. “We broke quite a few at the start,” Perl admits.

Wow factor at the back: Perl and Kendrick now enjoy an extended kitchen-living room at the back of their house


The build began in June 2014 and was completed in an impressive three months. In place of the conservatory, Perl and Kendrick now have an extended kitchen-living room — also with timber linings. Upstairs is a quiet bedroom with exposed roof timbers and an en suite bathroom.

Outside, the architect paid a lot of attention to detail. The timber curves are attractive, and a sort of timber flying buttress adds interest. Punctured by well-placed windows, the double extension is light, practical, and warm.

Working with a joiner was crucial, for the detailing of the wood is very neat, and it is just such things that make or break a marriage of old and new like this one. Ben Perl’s house has been nominated for an Architects’ Journal small projects award.

House in 2010:
Works including architect and planning consultant: £122,000
Value now: £1.3 million

Simon Gill at
Planning consultant: David Lamont at
Builder: ALS Contractors via email -


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