Preserving Post-War Heritage At the RIBA, Portland Place, London W1 on 3-4 June
This, the second English Heritage conference on conserving post- war buildings (after 'Modern Matters' in 1995), was a highly stimulating two days - a heady mix of high-flown theory (Alan Powers), incisive history (Elain Harwood), and technical know-how (Peter Ross and John Redding of Arups, among others). Conservation is a good way to study architectural technology, since it concentrates on defects, their causes and remedies, and whether you are a conservationist or a Pawley-ite, defects are something you want to avoid; which is not to deny that a whole day devoted to decay and its causes can have a demoralising effect.
The spectre of Martin Pawley was in fact present at the feast and, together with the aj's editorial of 28 May, provided Alan Powers with the starting- point for his paper 'Style and Substance', in which Pawley's arguments were ably demolished, and guidance sought instead from St Thomas Aquinas, Mies van der Rohe's favourite reading. The Thomist distinction between essence and substance was held to have relevance to the question of what and how to conserve in architecture.
Behind this lay the continuing quest for that elusive goal - a conservation policy that can somehow be flexible enough to allow substantial alteration to a building but still retain the essence of what is valuable. Certainly what has happened at Erno Goldfinger's Alexander Fleming House, now coloured cream and blue, can hardly be called a successful example of such a policy, as several speakers agreed, though Martin Cherry of eh seemd to imply at one point that it was.
Goldfinger was another spectre at the feast, the coloured glass window of Alexander Fleming House acting as poster image for the conference, and his work being referred to by many speakers. eh's Martin O'Rourke, in particular, spoke of the recent replacement of a whole facade of sound double-glazed timber windows at Balfron Tower with pvc, an outcome he agreed might have been improved upon had listing come earlier; he also spoke lovingly of the well-preserved nearby Lansbury Estate where the pub still bears the Festival of Britain logo, but where 'the right-to- buy is beginning to bite'.
Tony Walker (senior partner of Damon Lock Grabowski) seemed on the other hand to derive positive pleasure from the thought of pvc windows, since plastics was his subject; he gave a fascinating history of the material starting with gutta percha urns at the 1851 Great Exhibition, and had so much to say that there was little time to talk about how to conserve it. Plastics have not fared very well in architecture so far, all the glc's grp-panel SF1 point blocks of the late 1960s having been demolished, and Stirling's Olivetti wing having had problems from the start. But Grimshaw's Herman Miller factory panels have recently been successfully re-sprayed.
Perhaps in deference to the two American speakers, the conference title referred to 'preserving' rather than 'conserving', and their contributions were certainly very worthwhile. Robert Silman, the structural engineer from New York currently developing methods for halting the progressive sagging of the terraces of Frank Lloyd Wright's (not quite post-war) Falling Water, gave a fascinating account of the structure. The master-bedroom terrace, which seemingly cantilevers 20', and in which cracks had been observed, is in fact supported off the metal living-room window frames below - and was always designed to be so. The living-room terrace sags about 7' under this load, and is currently supported on temporary props off the stone shelf of the waterfall, which itself is propped from beneath. The massively stone-paved floor of the living room is in fact hollow, the stones resting on a ply deck on 2' x 4's; this allows convenient access to the ribbed concrete structure beneath, where additional reinforcement will in due course be concealed. Wright's argument at the time against more reinforcement - that its extra weight would weaken the beams - was quite false (the contractor slipped in some extra anyway). But Silman, as an engineer, was more generous to Wright than Wright ever was to engineers.
Stephen Kelley (of Wiss, Janney, Elstner Associates, Chicago) gave a history of curtain walling, its problems and remedies, but his opening aerial shot of downtown Chicago with high-rises disappearing into the distance, and further shots of hurricane damage on the Gulf of Mexico, made European problems seem puny, as did his current project which involves inspecting 655 apartments. Perhaps Park Hill, Sheffield, presented by the city architect, runs this close.
John Winter (in the chair) remarked that 30-40 years ago reinforced concrete was the wonder material; now, said Michael Bussell, it seemed the source of all ills. The familiar causes of its decay were clearly presented, together with more novel methods of treatment, particularly implanted cathodic protection. But the example of this shown was visually disappointing since the concrete still had to be coated. An adequate method of conserving fair-faced concrete without altering its appearance is an essential that seems to remain elusive. But, said John Winter, the focus of the conference should have been less on simply conserving ('the easy bit') than on upgrading. James Dunnett is an architect inLondon