Provoked by higher-density townhouse development, housebuilders are finding ever more imaginative ways of exploiting the sales potential of the roof – building both beneath it and on top of it


You know that an issue is rising to the top of the agenda when London mayor Ken Livingstone and his chief architectural adviser, Lord Rogers, have something to say about it. Last month the pair issued a statement promoting green roofs, roof terraces and roof gardens, declaring that roofs were “London’s most underused assets”.

Housebuilders cannot be accused of failing to innovate on this particular point. Even though many office blocks and shopping centres are still topped with unsightly plant rooms or a profligate architectural flourish, city centre apartment schemes are now customarily crowned in lavish roof terraces, and it has become routine to convert townhouse roofs into additional rooms.

Living in the roof

In the space of four years, housebuilders have undergone a conversion of their own, driven to create rooms in the roof by PPG3’s demand for higher-density townhouse development.

Four years ago, the Living Roof Association, an organisation that has since bitten the dust for want of a cause, charted housebuilders’ resistance to rooms in the roof. The housebuilders it spoke to complained that such rooms cost about £10,000 to build, but buyer resistance meant that the extra space only achieved about three-quarters of the sales value of the standard square footage rate. Buyer perception has now changed. “With PPG3 the public is seeing more three-storey townhouses, and buyers have got used to it,” says Paul Hogarth, sales and marketing director at Laing Homes South-west.

Laing Homes was one of the early adopters of rooms in the roof, marketing the concept to customers by renaming the loft the “bonus room”. In creating a new purpose for the loft, the housebuilder was careful not to abandon its traditional use as storage space. In collaboration with research group the Henley Centre, Laing produced a storage Charter that combined the room in the roof with eaves storage space.

Encouraged by PPG3, some housebuilders are evolving room-in-the-roof design from basic bedrooms for the kids into multifunctional and sometimes rather grand spaces. Laing Homes has recently fitted out four-bedroom show homes in Cobham, Surrey, with home office and cinema, and it has put three rooflights into an already well-lit penthouse in Barnes, west London. “That’s expensive to build but it creates a really impressive property,” says Hogarth.

Other housebuilders are also exploiting the sales potential of the top floor of the townhouse. “Rooms in the roof can create drama with cathedral-like ceilings,” says Andy Wibling, chief executive of Sunley Homes, which has made maximum use of roofspace at its Lacuna scheme at Kings Hill, West Malling in Kent.

Green tops

Because Lacuna is a high-density scheme, its garden space is limited, so the housebuilder has turned garage tops into terraces. “There’s not a flat roof there that hasn’t got a deck on it, and buyers love it,” says Wibling.

At its Clarendon Heights scheme of apartments and houses in Sevenoaks, Kent, the housebuilder has created another roof-top feature in the form of a green roof, planted with slow-growing sedum. Two areas of the scheme were planted to limit the visual impact of the development. “It is a steep-sloping site and purchasers and neighbours look down on the roofspace,” explains Wibling.

Sunley used a specialist supplier, Bauder, and found the process of creating the green roof to be straightforward. The costs of green roofing are, however, high, with Sunley reckoning it paid a premium of about £1000 per 10 m2 on a conventional flat roof.

The prospect of having green technology on the roof neither won nor lost buyers, says Wibling. “Like most environmental issues you explain to buyers what the advantages are, but that’s not their buying decision. They weren’t put off though, as we explained that it gives the roof more protection and that the maintenance is simple – the roof only needs to be looked at twice a year and the cost of doing that is included in the maintenance charge for the apartments.”

Although costs may be a deterrent to “greening” domestic roofs, Wibling believes it is something housebuilders will be doing more of. “I think we’re going to be asked to use them more, especially in higher priced developments where density produces an intense roofscape.”