Ruskin

Seems like an appropriate quote in the context but a bit long for a strapline...

"see if it looks as if it had been built by strong men; if it has the sort of roughness, and largeness, and nonchalance, mixed in places with the exquisite tenderness which seems always to be the sign-manual of the broad vision, and the massy power of men who can see past the work they are doing, and betray here and there something like disdain for it. If the building has this character, it is much already in its favour; it will go hard but it proves a noble one"

John Ruskin, "the nature of gothic" in "stones of venice", 1851-1853 (cut and pasted this from Seier+Seier's Flickr site which is well worth visiting).

Here's another which most architects would probably accept as their epitaph...

'I tried to draw a few simple lines on the sky; and now my will has to support a whole world up there, before I can do it.'

'The Spire', William Golding