Upon its move to London, the Institution rented premises at No 10 Victoria Chambers, where it remained for 20 years. In 1895, the Proceedings report that, ‘On the motion of Mr Mair-Rumley, seconded by Mr Head, it was resolved that the President be requested to represent to the next Council Meeting that the time had now arrived when the question of a House for the Institution should again be seriously entertained.’
The President, Alexander Kennedy, immediately drew the attention of the Committee to the availability of land on Storey’s Gate. The row of houses facing St James’s Park had been demolished, leaving prime building land. Alternatives also considered were Delahay Street, Whitehall, Artillery Row or Victoria Street, but the Finance Committee soon agreed on the Storey’s Gate site.
A House Committee was then formed to work on the new headquarters. On 14 June 1895, the Institution made an offer of £9,500, which was accepted. Hoardings were erected, and excavations commenced. In 1896, Builders’ tenders were received, and the firm of E. Lawrence and Sons were selected. The foundations were completed by 1896, despite difficulties thrown up by the discovery of running water 22 feet underneath the site. Disputes with neighbours meant that work on the building itself could not begin until 1897, when London County Council approved the plans. Construction took two years, funded by the sale of stock debentures. On 22 June 1898, the House Committee was able to hold an informal meeting in the building.
The original land owners, The Storey’s Gate Syndicate, had believed that the best use of the site would be for flats. Basil Alfred Slade was the vendor’s architect, and he had already developed a plan for the residential building. He was also employed by the HM Office of Works building, which shared the Storey’s Gate site. The original plan, a symmetrical block with a single entrance, in the Queen Ann-revival style, was adapted for the headquarters building. Slade’s final design incorporated details and inspiration from Renaissance, Jacobean, Elizabethan, Venetian and Georgian styles. Inside, there were many state-of-the art features, such as a telephone; a 54-inch fan in the lecture theatre, for driving St James’s Park air into the building; an electric lift from the Otis Company, and a Synchronome master-clock, which controlled all house timepieces.
The building was officially opened on 16-17 May 1899, celebrated by a two-day conversazione for members and 750 guests, drawn from government, industry and academia. A carriage awning was erected in St James’s Park, and there were entertainments inside from the Meister Glee singers, London Concert Orchestra, and cinematographs.