By an odd and fortunate coincidence, my copy of a new and excellent volume of essays about the work of Denise Scott Brown arrived last week just at the moment when I was considering the issues surrounding the original design of the Sainsbury Wing and the current proposals for its redesign by Annabelle Selldorf:-
To an extent I half knew, but only half, Scott Brown was heavily involved in teaching about issues of urban form during the mid-1960s, including courses on ‘Form, Forces and Function’ at the University of Pennsylvania in fall 1963 and fall 1964, and then, again, in the University of California Berkeley in spring 1965 and at University of California Los Angeles in fall 1966 where she was appointed as a professor. She was due to write a book on ‘Determinants of Urban Form’ for which she was given annual leave to write it in 1967, of which the manuscript survives but has never been published. It was then that she first formulated her view of the need for flexibility in architectural design, writing in the notes for her lectures how
City form tailored too specifically to the special needs of one population at one time may become functionally obsolete long before the end of its structural life, whereas form designed to suit ‘functions’ more generally defined may prove less efficient for any one specific need, but over the span of its structural life more useful to more people.
This was when many of the ideas which appeared in Learning from Las Vegas were first formulated and indeed she took Robert Venturi to visit Las Vegas when he came out to stay with her in Los Angeles in November 1966 before they were married in July 1967 and taught a course together on Las Vegas at Yale in fall 1968.
Key to her thinking was the idea of the glove and the mitten, the glove being highly specific in the way that it allows patterns of use, whereas the mitten is more generous and less determined:-
I can see now why Annabelle Selldorf showed this image in her lecture about the Sainsbury Wing. She did not state it quite explicitly, but the issue is clearly whether one treats the Sainsbury Wing as a glove or a mitten. Should its use be precisely as it was when it first opened in 1991 or should its use be allowed to evolve to a limited extent in order to acknowledge the changing requirements of the client and changing attitudes towards public use ?
I can see the argument for retaining the absolute integrity of the Sainsbury Wing in its original form because of its exceptional historical importance; but I am not persuaded that modifying its entrance as is now proposed by Selldorf necessarily damages its essential integrity, particularly now that the modifications are being done in a style that is more in sympathy with the classical language of the original architectural forms and, indeed, the changes to the space immediately outside the Sainsbury Wing, which will be enlarged will, I think, enhance its public visibility and its relationship to Trafalgar Square.
The Sainsbury Wing is indisputably a work of exceptional architectural interest and importance. But upgrading and renovating its entrance, making it more spacious and getting rid of later irrelevant accretions, could be viewed as an act of homage to it, not an act of desecration.
 Denise Scott Brown, ‘The Definition of City Form: Form and the Designer’ cit. Denise Costanzo, ‘The Function of Functionalism’ in Frida Gahn (ed.), Denise Scott Brown: In Other Eyes, Portraits of An Architect (Basel: Birkhauser, 2022), p.81.