John Buchanan lived at No. 4 from 1872 to 1883, when he moved to No. 7 where he lived until 1890.
John Buchanan was born in Edinburgh c.1842. He appears to have been unmarried, and in 1881 was living at No. 4 Malta Terrace with his sister Mary. Like his partner John Bower Bennett he may have had a connection with the RC church.
Buchanan was primarily a civil engineer and surveyor. He commenced practice at 17 George Street. Edinburgh about 1868-69, moving to 24 George street in about 1870. In about 1888-89 Buchanan took James Bower Bennett into partnership, Bennett taking over his former house at 7 Malta Terrace after Buchanan moved to a grander residence in Great King Street. Their partnership was dissolved c.1907. Buchanan retired or died in about 1909-10 when his practice was taken over by Walter Linton who adopted the practice title of Buchanan & Linton and moved office to 133A George Street.