Restoring Le Corbusier's work – a new relationship with heritage
JUDI LOACH reports from La Tourette, where a conference addressed the challenges of restoring Le Corbusier’s legacy
First published Winter 2013
In this springtime conference held at La Tourette to celebrate the completion of the long drawn-out conservation project there, architects and Inspectors of Historic Monuments responsible for half a dozen Le Corbusier buildings presented their recent conservation work. The introduction by one of the Dominicans living in La Tourette raised the issue of whether 'restoration' there should 're-establish the ruin' as it was at its'origin' – the beginning of the architect's discussion with his clients and his first designs – or at its 'beginning' – the moment when the building was finished. Given that the building's function has changed, how far should it be restored to a state identical to that when it 'began'? Should one instead return to the 'original' aim of providing a simple, even 'poor' home, fit for current purposes?
Marie Bardisa, the regional director for Historic Monuments, developed these issues more widely in relation to the various projects to be examined. She questioned how far, in the course of conservation, 20th century 'monuments' can be changed without losing their 'nature'. Lighting arrangements can easily be changed in historic churches, castles or country houses without changing the building's essence, but less so in the case of Modern buildings, where they play a more intrinsic role. Construction details are often key in Modern buildings, but when space was intended to be flexible, exploiting this potential can put these details at risk. Many Modern buildings were poorly built – not least Corbusier's, and notably La Tourette – so should they be 'improved' in restoration, so as to ensure better performance, thus safeguarding their continued use and indeed existence? If a sanitary or lighting fixture is no longer in production should one commission a few expensive reproduction items, or rather follow the original intent, using economical products available today? At La Tourette the architect and Inspector had to fight the fire authorities in order to avoid fireproof screens around stairwells and firedoors in all corridors (they lost this battle in the guest accommodation).
Didier Repellin, conservation architect for La Tourette, began by describing its construction, rapid ageing and particular weak points: roofs leaking from as early as 1958, the oratory's pyramidal roof needing annual repair from the early ‘60s, glass panes regularly 'bursting out' (noisily!) and rusting rebar (or sometimes just wire) leading to 'exploding' concrete. To save money Dominicans had tended to do DIY repairs, with some ingenious (but dangerous) use of sellotape! Roofs are now repaired by injecting resin into minor cracks and replacing zinc sheeting, but also increasing gradients to improve drainage. Most structural concrete only required careful patch repairs, but a few pillars were found to have 'turned to icing sugar' inside and were therefore replaced, with formwork precisely imitating the original boardmarking and concrete mix colourmatched to the original. The pebbled panels
on the entrance façade were found to be held in
place by (rusting) wires, and some by friction alone; single pebbles were removed, to allow insertion of stainless steel ties and resin, then carefully replaced. Trials preceded cleaning of the concrete surfaces, with high-pressure water used for all but the church interior where cryogenic cleaning was adopted to reduce dust. Layers (sometimes numerous) of later paint, cement
or mastic were removed, regaining lost profiles – the greatest plus in this project? – and revealing that
the earliest colours used differed in shade across
the building, also that previous restorations had underestimated the effect of sunlight on discolouring. Most significantly – and controversially – archival and material research convinced Repellin that Corbusier had intended to distinguish between adjacent storeys by using contrasting shades, which he has reinstated. The ensuing guided tour raised issues of inserting fire detectors and extra cabling as invisibly as possible (cabling and ducting had never been executed as
in Corbusier's drawings), the latter by weaving it in through cupboard spaces wherever possible. Again controversially, paving slabs now mark the footpath around the edge of the hitherto wild grass roof, justified by their presence in Corbusier's drawings,
and his correspondence indicating that their absence earlier was only due to cost.
The most criticised conservation turned out to be
that at Firminy (this conservation architect sent
his assistant!), despite being better built in almost undamaged concrete. Surprisingly, the walls of the church's ground floor – built in the early 70s and listed a decade later – were thickened so as to be flush with the new upper storey and its thicker insulated skin (to comply with current regulations), rather than making the upper storey fit to the existing. Worst, the Unité,
as social housing is subject to legislation enforcing double glazing but a minimal budget available dictated that the original forms were lost. The MJC has been treated more sensitively: the cable roof – the first in France – had survived well, so just a few cables and rubber fittings were replaced. In principle its windows have been renewed identically, pane by pane, but for cost reasons those that had been changed over time were not taken back to their earliest form, however, door handles have been remade to match originals (albeit in plastic, not bakelite). Fortunately lack of funds spared the stadium canopy from a plan to triple its extent, supposedly in order to realise Corbusier's unexecuted drawings.
François Botton introduced the Marseilles Unité by warning of concrete's fragility despite its 'illusion of eternity', particularly when used in coastal regions subject to high salinity, and especially with only thin concrete cover to the reinforcement. Many claustra had to be replaced, as did those pillars that turned out to be built without cement (!), but wherever possible just surface repairs were made using liquid concrete. As an experimental and surprisingly handmade building, he emphasised the need to first understand all previous repairs; those of 2000-01 had actually produced worse decay than in untreated areas. Exemplary investigation (onsite and archival) into each element ran in parallel with trial repairs. This revealed that, as at La Tourette, Corbusier used slightly different paint shades across the building, but here seemingly for economy (buying the cheapest available and
using up all leftovers). The major problems here have arisen with the fire mid-project (2012); although this only directly affected a few flats, another twenty and nearly a hundred front doors, were destroyed due to the firemen's interventions. The fire had revealed that many walls assumed to be concrete are just metal and wood. As only exteriors and public areas are listed, flats will be repaired in accordance with current norms; however, the quantity of damaged units has enabled some internal fixtures – e.g. stainless steel sinks – to
be reproduced copying originals. An ongoing court case against the fire service has effectively halted
the project and its outcome is likely to impact upon treatment of fires in Historic Monuments.
The Cité de la Refuge in Paris has intrinsic problems due to only parts being listed (facades, roof, entrance staircase and hall), its performance (inadequate acoustic isolation for social housing) and subsequent modifications to fit changing use (notably from dormitories to single bedrooms), even during Corbusier's lifetime. In fact, there were two Corbusier projects (1930s and 1950s) each with variant details, neither fully executed and with it now unclear
what was... and there was a potentially listable Candilis extension. So, François Chatillon asked, is its 'authenticity' defined by the material, the 'spirit' or the way it came into being? As state-funded social housing, a maximum number of bedrooms was required in the refurbishment to maximise rentals and rooms therefore no longer match Corbusier's grid. The problems of making the building compliant with current norms and comfort standards were a nightmare and a building permit was only secured after several attempts. In this complex situation the project does its best to restore known Corbusier work, albeit sacrificing Candilis'. It reconstructs several lost elements, such as the entrance counter, from Corbusier's detailed drawings. As elsewhere, Corbusier's use of colour turned out to be less consistent than he had claimed!
Investigations at Ronchamp have proved illuminating. Richard Duplat explained that a local architect had prepared a scheme by mid-1950 that would repair the previous, war-damaged church. Then local people decided to ask Le Corbusier for an entirely new building, but given the lack of budget, decreed it was to be in stone salvaged from the church to be demolished. So Corbusier's building – situated in 'an extreme climate' – is, apart from its concrete coque, made of (porous) stone, held together and sprayed over with cement (Corbusier had more sensibly recommended limewash, not cement, in part because he realised local artisans would build it). Bolle-Redat, the chaplain until 2000, had 'saved money' with DIY redecoration using gifts of synthetic paint from manufacturers (in exchange for rights to use Ronchamp in their publicity). As at La Tourette, glass set directly into concrete has often cracked, only here it was often handpainted by Corbusier (albeit often repainted by Bolle-Redat!), so must be repaired rather than replaced. The concrete coque, formed with an early use of gunnite, concrete sprayed over wire netting, has corroded, 'exploding' the concrete skin and test panels are currently in process. Damp problems have long plagued the building and cracks began to appear early on (notably in the tower), largely as a result of water ingress followed by freeze-thaw cycles and/or problems at material junctions. Cracks have been 'invisibly' repaired after trialling various supple mortars. However, high-tech examination revealed that, beneath the thin cement skin, the stone structure has often disintegrated, to the point where collapse is possible. Although 'one would normally rebuild', happily Duplat is instead 'advancing with prudence', resigned to repairing every decade or so...
Michel Richard, director of the Fondation Le Corbusier, summarised the situation at Roquebrune: a site itself listed on grounds of natural beauty, and containing listed buildings by Eileen Gray, Corbusier, and his godson Robert Rebutato (developing a Corbusier sketch design). The coastal situation, the amount of timber used (as opposed to concrete), the small scale of all the buildings and the fragility of its mural paintings makes this a delicate site, unsuitable for mass tourism. The day concluded with words from Jacques Repiquet, an architect specialising in conservation of Modern architecture. Whilst the majority of Corbusier's buildings are now listed, he recognised that the fact
it is usually only in part complicates conservation and leaves most interiors unprotected. The Fondation contains a fuller archive than exists for any other Modern architect, but the evidence it offers is often contradictory, and can be further contradicted by the material evidence of the buildings themselves. In any case, conservation is not a simple matter of stopping the clock at a given moment in a building's history, but needs rather to conserve the building in a way appropriate to current and future use.