Addyman Archaeology undertook Historic Building Recording as part of a wider programme of alteration and extension works at the National Gallery of Scotland, Princes Street, Edinburgh. Photogrammetry of all four external elevations of the building was undertaken as part of an initial Dilapidations Survey, produced for architectural purposes. The Historic Building Survey recorded all internal areas of the building subject to alterations prior to and following stripping out and down-takings. The National Gallery appears to have been built in a single phase, with small subsequent alterations, probably dating to the transformations of the second half of the 20th century.
Ruchonnet et al. (Sat,) studied this question.