The model displayed in the Royal Festival Hall is pernicious because it is entirely made of plastic and is totally transparent: the only things solid are the tiny figures representing people. It thus conveys to the unsophisticated viewer an illusion of being made free by space. The Queen Elizabeth Hall and the Hayward Gallery seem to be part of a total fairground, not solid lumps interrupting the space. And a glass tent is one of those ideas that look masterly in the plastic model, but mean something else entirely once built, when problems of environmental control, energy conservation and simple cleaning thrust themselves forward.
The proposal's effect on the Royal Festival Hall is disastrous. It becomes largely confined and entangled in the skirts of the glass tent. The views from its terraces are spoiled, its relation to the river front is compromised, and questions are raised about public freedom of access. Rogers showed mastery when he placed the Pompidou Centre into Paris, relating it to the street pattern and giving it a spacious piazza. Here, his tent invades the Festival Hall's civic space and crowds it out.
The glass tent is one of those populist ideas that has become another cliche. There is a place for it, but not here, not at the centre of London. The proposal is part of an expressionism that seeks to liberate the architect's gesture, so that he can be as "radical" as the artist. But architecture cannot ignore the city in which it finds its place.
The Festival Hall was never radical, but has always been popular, because it epitomised the egalitarian spirit of the post-war Labour government. In the post-war years it stood for modernity and, as Sir Hugh Casson hoped, it made modernity lovable. As a Grade 1 listed building it is entitled to more consideration than is here allowed it. As a people's palace, it is entitled to the respect of a government of the people.
It is to be hoped that Lambeth council will know where its duty lies, by rejecting Lord Rogers' proposal.
The writer is Emeritus Professor of Architecture, Princeton University