The shortlist for this year's Royal Institute of British Architects Stirling Prize was announced yesterday, but the group of six buildings doesn't include the refurbished National Theatre, which was one of the 37 National Award winners. I recently dropped in there to escape a dust storm and sipped my coffee slowly while I spotted a number of household-name actors outside on the South Bank, but my attention was drawn more to the unfinished concrete wall beside my table. The surface reminded me of some of the works of Boyle Family, led by Scottish artist Mark Boyle, who in their Earth Studies series, make large casts of mostly randomly chosen locations around the world. I remember watching a BBC Arena programme about this project in 1979 and being completely in awe, but not as much as I was when I was lucky enough to meet Mark Boyle in person in his gallery in 2005, just shortly before he died. For a five minute film about Boyle Family, please visit tate.org.uk/context-comment/video/tateshots-edinburgh-boyle-family.