As a nation we are precious about our architectural heritage.We find the radical reworking of industrial buildings (Tate Modern, Magna) easier to stomach than the evolution or reworking of significant public buildings, and the single big move (the Great Court, Sackler Galleries) more acceptable than the more subtle weaving together of old and new. How apt that Foster, whose oeuvre is the antithesis of the complex layering of, say, Carlo Scarpa or Giancarlo de Carlo, has come to be one of the nation's leaders in historic buildings work.
Historic building projects submitted to the AJ are invariably accompanied by a 'design philosophy'which states that 'the old is left intact while new elements are clearly expressed as such'- a mantra which is now so widely accepted that it has become the touchstone of planning authorities throughout the UK. Without denying the value of this philosophy, it is important not to underestimate the validity of 'invisible'historic buildings work.Expressive contemporary additions are notably absent at Frank Lloyd Wright's Florida Southern College - the subject of this week's building study.Having spent nine years updating the campus, John McAslan's 'signature'moves amount to little more than some gleaming new service ducts. These additions are the tip of the iceberg: the visible manifestation of a predominantly invisible project which includes re-routing services, enlarging the basement, removing partition walls, repairing leaking roofs and replacing Wright's concrete blocks.
Far from being 'dishonest' the seamless interweaving on Wright's and McAslan's work marks a profound respect for the original.Wright's work is not isolated, but is woven into the process of architectural evolution. Much of his work was experimental: the concrete blocks which he proudly predicted would last 1,000 years, had in fact deteriorated within 20. Sixty years on, having learnt from Wright's mistakes, McAslan and Arup have come up with a replacement mix which they are confident will fare better.
The passage of time, and the evolution of technology, make it realistic, rather than arrogant, to assume that we can improve on the past - even on genius.