30 Cardozo Street (2013) by Jack Wooley is a partially subterranean house built to preserve the existing long view across the site from street level.
30 Cardozo Street (2013) by Jack Woolley is a partially subterranean house. Its design maximises the small plot while preserving the existing long-view across the site from street level. It features in this year’s Open House London

With soaring house prices and a deepening housing shortage in London, developers, clients and architects are scouring the city for leftover scraps of land. Awkward plots previously not worth the time, effort or money to build on are now being eyed as opportunities for innovation.

Will Burges of 31/44 Architects charts the history of the infill phenomenon as being inherently tied to Britain’s shifting social landscape. In the early 20th century, mews houses were developed when owners no longer needed somewhere to store their carriage, horses and domestic ‘help’, he explains. ‘Similarly, a reduction in car ownership and the fact that modern cars can be kept outside means that generally garages are just extra, often abandoned storage areas.’

A typical London garage may be worth £15,000. But ‘if you have a cluster of them the value, with a residential consent, significantly escalates,’ he says. His firm has half a dozen such garage sites under development, and architects vPPR are also developing three garages into homes in Queen’s Park.

vPPR's Ott's Yard comprises two new triangular houses on an infill site in the centre of a residential block in North London. Accessed via a long narrow passageway, the site has 23 party walls. Photography: with 23 party walls.
vPPR’s Ott’s Yard (2013) comprises two new triangular houses on an infill site in the centre of a residential block in North London. Accessed via a long narrow passageway, the site has 23 party walls.

Housebuilding on infill sites is no walk in the park though. They typically come with a raft of challenges and ‘take around 30% longer to complete than a conventional property of the same size’, says Luke Tozer, principal of Pitman Tozer Architects.

But perhaps the greatest challenge is getting planning permission through and getting the neighbours on board. ‘The whole neighbourhood can gang up (against a proposal),’ says Catherine Pease at vPPR.

Such animosity often has a lot to do with these plots’ proximity to other properties. VPPR’s Ott’s Yard, for example, had 23 party walls.

Proximity to neighbours and the small, awkward shapes of sites mean that specialist construction techniques beyond the expertise of general contractors are often needed. Even storing building materials on site can be a headache.

Pitman Tozer’s site office for its 2008 Gap House project was a shed on wheels that could be moved to make way for construction on the small plot.

Ott's Yard by vPPR xxx
Ott’s Yard features a sloping green roof with skylights that flood the interior of the property with natural light, without overlooking neighbouring properties.

Meanwhile, architect Jack Woolley built Spiral House in Wandsworth on a plot covered in Japanese Knotweed. ‘This made excavations more complicated as the rhizomes are considered hazardous waste’, he says.

With such difficulties, it’s no wonder that infill projects appeal to less established practices keen to prove themselves and raise their profile.

Pease says that vPPR’s infill work has defined the practice. ‘We’ve had to think of new ways and ideas to apply to these weird sites.’

Woolley backs this up: ‘The projects are well worth doing because you learn so much – they are very interesting to work on and they can be a good showcase.’

2015-Spiral-House-8
Spiral House (2015) by Jack Woolley sits on a former garden site and is concealed from street-view by a brick boundary wall.

And such high levels of creativity from emerging firms can be a contemporary shot in the arm for a street of period housing stock. Good infill homes do not apologise for their arrival on a street, rather they celebrate it with their strong design.

‘You have to do something fairly radical on these sites because they’re not suitable for a terraced house, that’s what’s great about them. Building a square on a triangle doesn’t make sense,’ says Pease. VPPR has developed its own ‘language of geometry’ through its Ott’s Yard and Vaulted House projects.

With 31/44’s proposal for East Dulwich House, ‘The plan layout strives to make a deliberate character from the peculiar-shaped plot, so it doesn’t feel like a leftover fragment when it is built,’ explains Burges.

1401 House in East Dulwich will occupy a tight and irregular end of terrace site. 31/44 Architects will transform the workshop site into residential, using courtyards to bring light into the property while minimising impact on the privacy of surrounding properties. Work has just begun on site. Plans courtesy of 31/44 Architects
1401 House in East Dulwich will occupy a tight and irregular end of terrace site. 31/44 Architects are transforming a former workshop into residential, using courtyards to bring light into the ground floor while minimising impact on the privacy of surrounding properties. Plans courtesy of 31/44 Architects

These architects are cautious, however, of the idea their design efforts are raising the bar for residential developments in general. It is the challenging nature of infill sites that drives creativity: ‘These sites are where good design adds the most value, where it is demanded rather than just nice to have,’ says Tozer.

Smart examples of infill architecture in London