By the early 1900's, the Mactaggarts and Mickels had come together and with others, who would later establish their own shorter lived building companies, were constructing tenements in the West End of Glasgow. They had also built in London's Portland Place but their Glasgow tenements are now locally recognised as the pinnacle of achievement in tenemental construction.

The opportunities offered by the government to be involved in a housing boom following the First World War were not missed. In the four years from 1922, in Glasgow and in Lanarkshire, the Mactaggarts and Mickels in partnership built over 3000 houses for local authorities before registering as a Limited company in 1925.