The partnership of Orphoot & Lindsay was dissolved in 1952 when Burnett Napier Henderson Orphoot retired. George Hay and another assistant of Orphoot and Lindsay's, Walter Schomberg Scott, were taken into partnership as Ian G Lindsay & Partners, based in the ground floor and basement of 17 Great Stuart Street, which had been Playfair's office, and later Lorimer's, and had been bought by Maysie Lindsay in 1956. A friend of Ian Gordon Lindsay's, D Alan Stevenson, last of the harbour and lighthouse engineering family, lived in the floors above. The Roman Catholic artist and writer Peter F Anson still did Lindsay's presentation perspectives and for a time lived in the basement at Houstoun. The practice expanded rapidly, mainly on church, country house and hydro-electric work, but was not without problems. Lindsay was over-committed as chief investigator of historic buildings and as a member of virtually every body concerned with Scottish heritage; and although most of it was done at weekends he necessarily spent a lot of time visiting and socialising with clients and on researching and writing his books. Hay had more work than he could do and sometimes became stressed; most seriously Scott's clientele was something of a separate entity within the practice and Lindsay and Hay were not always happy with his work, either aesthetically or technically. Like Lindsay, Scott came of a very influential background. Born 14 September 1910 at Monteviot House, Roxburgh, he was the son of James Cospatrick Hepburne Scott, 2nd son of the 7th Lord Polwarth and Lady Isobel Alice Adelaide Kerr, daughter of the 7th Marquess of Lothian. He had studied at Edinburgh College of Art in 1930-35 and had worked in the office of Reginald Fairlie in 1934-35. During these early years he travelled extensively in Italy, Holland, Germany Sweden and France. In 1936 he moved to London to work for T A Darcy Braddell of Deane & Braddell, but returned to Edinburgh to work for Orphoot Whiting & Lindsay in 1937. His home address was then Broomlands House, Kelso. He was admitted ARIBA in that year, his proposers being Fairlie, Braddell and Orphoot. Later he found employment in London with Edward Maufe by whom his work was for a time strongly influenced. In person he was a small and slim man with a military moustache. His marriage on 15 February 1945 to Deborah Castle, a grand daughter of ___ Howard of Castle Howard, extended an already very wide range of social connections.
Although Lindsay was then still serving in Germany, his National Trust (or 'Bute lists') had been adopted by the Department of Health in 1945 as the Town & Country Planning Acts had made it a statutory requirement to compile lists of buildings of special architectural or historic interest. It was quickly realised that the Bute lists were too narrow in scope and in 1947 Sir Robert Russell, who returned from India as an assistant secretary at the Department, decided to have the necessary resurvey carried out by retired or under-employed architects, following the criteria which had been set out by the Maclagan committee in London. For them Lindsay produced 'the child's guide' 'Notes for the Guidance of Investigators' issued in June 1948 which was considerably in advance of the English instructions in respect of Victorian and Edwardian architecture. The recruitment of part-timers, not all of whom proved to be elderly, greatly widened the Lindsay network, by far the most important of the early investigators being the Aberdeen architect Alexander George Robertson Mackenzie whom he had known before the war. Although Mackenzie was much older, he had a similar outlook on contemporary design and Lindsay was considerably influenced by his thinking. Other early investigators were Alan Reiach in Edinburgh; Robert Alison Crighton Simpson in Duns, a friend from his Cambridge days; Roy Carruthers-Ballantyne in Inverness; John Needham in Dundee; Joseph Weekes in Glasgow and Dumbarton; Antony Curtis Wolffe in the south west; and William Murray Jack in Fife; and after Weekes's death Alfred Lochhead was entrusted with Glasgow and Renfrewshire in 1955, while Catherine Holway Cruft took over Edinburgh from Reiach in 1956. Only Lochhead and Cruft carried out any serious research beyond what was strictly necessary for statutory purposes. Nevertheless the survey was the background to his 'Georgian Edinburgh' (1945) and 'The Scottish Parish Kirk' (1960) while the parallel researches of George Hay resulted in his much more comprehensive 'The Architecture of Scottish Post Reformation Churches', published in 1957. Lindsay and Hay both had a particular interest in the Roman Catholic churches of this vintage, restoring St Mahew's Kilmahew in 1953-55 for the traditionalist historian priest Father David McRoberts who was very architecturally minded. He became an important member of Lindsay's circle and was behind the commission for a large church in Greenock which was sadly never built.
Problems with Schomberg Scott's restoration work for the National Trust for Scotland at The Sandhaven, Culross, and a church with roof problems at Barrow-in-Furness led to the dissolution of the partnership with Schomberg Scott. His place was taken by John Herdman Reid, principally to deal with the new-build side of the business and bring it more in tune with the times. Symptomatic of the change was the laying up of Lindsay's Rolls Royce coupe (its top speed was only 55mph) and its replacement by a Jaguar coupe. But John Reid and George Hay were very different people: and in 1960 Hay regretfully withdrew to return to the Office of Public Works to be sure of retaining Lindsay's friendship which had begun to seem increasingly at risk. Hay's decision was deeply regretted by Lindsay who more than once observed 'Can't say I miss Scott but I miss Wee Doddie (Hay) dreadfully'. Fortunately by that date the main work on the drawings for Iona and Pluscarden had been done.
In 1962-63 Lindsay undertook a study tour of Australia to advise the Government of Australia on listing and conservation. He was invalided off the return voyage with glandular fever, and shortly afterwards broke a leg struggling with a ram while trying to get it into a boat in Mull. He never recovered properly from either of these mishaps; Hodgkin's disease set in and was not at first recognised for what it was. His last years were also clouded by the loss of the National Trust for Scotland as a client, the work being taken over by the Trust's surveyor under Robert Crozier with Schomberg Scott as consultant, an appointment which particularly upset him. Eventually he became bed-ridden at Houstoun. Although in great discomfort he sat up in bed, received clients and visitors, many of them from the conservation world, and generally did as much as he could. Eventually he had to be moved to Bangour Hospital where he died on 28 August 1966. His funeral was at St John's Church, Princes Street where he had remained a member, and in accordance with his wishes his ashes were scattered to a piper's lament from a boat in Iona Sound. His great book on Inveraray, for which Mary Cosh was initially the researcher, was unfinished at his death. It had grown out of his restoration work of the town of Inveraray for the Ministry of Public Building and Works and on Inveraray Castle for the 11th Duke of Argyll. It eventually appeared in their joint names in 1973.
The practice was formally dissolved by mutual consent on 9 March 1984. John Herdman Reid pratised on his own from 29 Mansionhouse Road and Crichton Lang, David Willis and Rognvald Galloway practised as Crichton Lang, Willis & Galloway from 3 Walker Street.
N.B. In 1975 the practice was a member of the Dalgleish Lindsay Group with offices in NAirobl, Athens and Lusaka.