sentences:  Playfair's National Gallery was laid out in a cruciform plan; he originally planned to build towers at the corners of the transverse central block, but these were abandoned during the project.When the RSA moved into the former Royal Institution building in 1912, the Office of Works Architect for Scotland, William Thomas Oldrieve remodelled the NGS interior to house the National Gallery collection exclusively.In the 1970s, when the gallery was under the direction of the Department of the Environment, the internal accommodation was extended.