Connect and contrast
Architect Eldridge Smerin's reworking and extending of a Victorian house has provided a radical addition to London's conservative Hampstead The most measured criticism by irate locals of this conservation area project is that it is not contextual enough. Others cannot contain their ire; one, quoted in the local paper, said: 'I've seen people shouting at it as they walk past because it offends them so much. How could the planners give permission to that?'
Well, the planners were OK about it, as were some of the locals. And in massing it has contextual qualities; the extension, for example, is the same height as the service accommodation that was demolished. And it replaces some less-than-contextual singlestorey garages. The client family is pleased, too. 'We didn't want anything showy and the result is light, airy and relaxing. When you go inside it feels as if you have escaped London, ' says Emma Shapero.
So there is a functional reason - creating a place apart - as well as Eldridge Smerin's compositional preferences, for making the new front, which in its own way is a little more opaque than the restored original facade. (You don't actually see much looking in through all those sash windows. ) After the practice's Stirling-shortlisted The Lawns, you might have expected planes of flowing space and floor-toceiling glazing. They are here, with a light slot between old and new and full glazing to the rear of the extension. From inside you don't miss the front as a source of daylight. (The light slots in the facade are to the kitchen and as screening to the parents' bathroom balcony. ) While old and new are very clearly contrasted on Pilgrim's Lane, the interior sense is much more one of connection. Yes, the new has steel columns and large areas of floor-to-ceiling glass. But the old has been stripped back and given the same vocabulary of moulding-free, white-plastered surfaces, spaces often divided by partial screen walls without doors, underfloor heating throughout, some of the furniture as well as fittings designed by the architect. At ground and first floor a steel-framed opening right across the flank wall of the existing house allows space to flow horizontally (see 'Structure'). On entering the house this openness and the stronger daylight in the extension draw you to it, making the old less dominant than the plan may suggest. Details too follow through. For example, in a neat touch the solid layered ply of the front facade is picked up in a solid-ply, computer-machined spiral internal stair down to the basement.
Daylight also helps make connections. The glass light slot not only creates a transition between old and new, aligning the house round its new central glass stair. Its light, combined with that from top-lit pods on the opposite side of the extension, mean that extension floors are more integrated spaces, not single-focus boxes oriented to the garden.
Extending the semi-basement still leaves that level somewhat enclosed (some spaces are mechanically ventilated and require permanent artificial lighting). But at the rear all rooms let onto a terrace and beyond that to the garden, by Jinny Blom, which slopes up away from the house. Its slope is steep enough that the extension's first-floor cantilevered balcony, with its glass balustrade, feels as if it is in the garden rather than above it. A long shallow ramp leads down from there to the garden surface.
This is not just another glass box extension. There is a richness that has come from subtlety in planning and in the handling of daylight and details, and from an enjoyable tension between contrasting and connecting the old and the new.
For the existing building, internal loadbearing walls were replaced with a 100 x 100m column plus new steel beams within the floor depth. The existing flank wall was completely removed between basement and first floor with steel framing supporting the masonry above and stabilising the opening.
The new extension is steel and timber framed, allowing connection of cantilevered pods and balconies; columns are square, channel beams are within floor depths.A new half-basement was built on mini piles.
New and existing are joined with minimal framing, with laminated glass flooring. The new stair has glass treads with a safety film; risers bear on a profiled and laminated glass wall. Connections use clear silicone and bearing tape.
Rear cantilever balconies consist of laminated glass floor panels and toughened glass balustrades, with steel flats providing framing and clamping plates.
In the garden a concrete table cantilevers from fairfaced concrete retaining walls. The table is 80mm thick and 3m long, with a stiffening rib concealed on the underside.
Karl Lang and Gary Elliott, Elliott Wood Partnership