|Former Lambeth school, 4402 Colonel Talbot Road, London|
iii. demonstrates or reflects the work or ideas of an architect, artist, builder, designer or theorist who is significant to a community.
Say you’re wanting to designate an old building or structure and you know its architect. How then do you make the argument that this criterion is satisfied?
Looking at many (most?) designation by-laws that reference connection to an architect, it seems enough to establish that a) so-and-so architect was active in the community for a certain period and was responsible for a number of works, including such-and-such, and b) this particular building or structure is one of them. Bingo, criterion met.
This essentially is what London did here. Not so fast, said the Board.
The property has design value or physical value because it,
i. is a rare, unique, representative or early example of a style, type, expression, material or construction method, …
Update: On September 19, 2017 the City of London decided to go ahead with the designation of the school. See http://www.lfpress.com/2017/09/19/mb-mceachren-school-old-school-makes-grade-despite-objections.
Best wishes, Su!