From Mr Roger Tarr Sir: May I support Sir Denys Lasdun's modest, but persuasive, plea ("Why my National Theatre should remain untouched", 15 December) that the overall design of the National Theatre should not be compromised by so-called "improvements". In spite of the unsym-pathetic picture accompanying his article, in it can clearly be seen the beauty of the composition of the building. There is an axiom in architecture that goes back to Vitruvius, at least, which says that beauty and fitness of a building can be found when nothing can be taken away from the whole except for the worse. This is the building's "integrity", as Sir Denys puts it, and there is no good architectural reason for changing it.
I have not seen the plans to demolish the lower terrace, but I am sure Sir Denys is right when he describes them as "acts of vandalism". I cannot bring to mind any building which has been actually improved by such tinkering.
Yours faithfully, ROGER TARR Department of Fine Art The University of Edinburgh