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 In Europe, the great modernist le Corbusier, saw an opportunity in his project for the Cite de Refuge, the Salvation Army Hostel in Paris.  Le Corbusier had already used a second skin glazing system in his Villa Schwob in his home town of La Chaux de Fonds in Switzerland in 1916.  Here very large windows (one of them two storeys high) were designed in two layers, with heating pipes between them, to prevent down draughts.  Le Corbusier's propositions 15 years later were much more adventurous, and involved two complementary building systems: one to produce what he called "respiration exacte" (a carefully controlled mechanical ventilation system), and the other the "murs neutralisants", what he called "our invention, to stop the air at 18°C undergoing any external influence.  These walls are envisaged in glass, stone, or mixed forms, consisting of a double membrane with a space of a few centimetres between them ... a space that surrounds the building underneath, up the walls, over the roof terrace.  Another thermal plant is installed for heating and cooling, two fans, one blowing one sucking; another closed circuit.  In the narrow space between the membranes is blown scorching hot air, if in Moscow, iced air if in Dakar.  Result, we control things so that the surface of the interior membrane holds 18ºC".

This proposition was much more than a rhetorical technological gesture.  It was considered with some rigour in a test chamber set up by the French glass manufacturer, St Gobain, in 1931.  The report on the tests carried out in the test chamber were interesting in the light of the proposition.  The test engineers concluded that the system benefited from a third layer of glass trapping still air to make the system viable.  This is not surprising: had section 4 of Scheerbart's "Glasarchtikectur" been noted, Le Corbusier and the St Gobain technicians would have read "To place heating and incandescent elements between the walls is in most cases not to be recommended, since by this means too much warmth or cold is lost to the atmosphere".  Le Corbusier was more interested to in the imagery and symbolism of technology than he was in working out the building physics.

Such was the basis of Le Corbusier's proposal to install the "mur neutralisant" in the City de Refuge.  The outcome provides one of the sad, or possibly humorous anecdotes of the modern movement. Le Corbusier was so keen to undertake the project that he offered a fee cut by 40%. Early projects had east and west facing walls, but, after battles with the Planning Authority the final project had its great glass wall facing just west of south.  The budget constraints were severe, and the building finished up not only single glazed, but without the full air conditioning which Le Corbusier had proposed.  Without either the "mur neutralisant" or cooling, the environment of the building was a disaster.  The Prefet de Paris condemned the building, which had been the subject of complaints by the occupants, and Le Corbusier had to introduce opening windows into his hermetic facade.  The environmental control of the building was eventually put right after a German bomb shattered the glass wall on 25 August 1944. The building was reclad in brise soleils between 1948 and 1952.  By 1947 Le Corbusier was advising Senator Warren Austin in relation to the United Nations Building of his strong belief "that it is senseless to build in New York, where the climate is terrible in Summer, large glass areas which are not equipped with a brise soleil. I say this is dangerous, very seriously dangerous".  In considering the history of the multiple wall this is doubly ironic.  Harrison's UN building worked because of the air conditioning cooling delivered by the system Le Corbusier could not afford in the Cit de Refuge 20 years earlier.  If the "mur neutralisant" had been tried for the UN Building, it would probably have worked.

© Michael Wigginton & Battle McCarthy 1st June 2000