The building at 136-140 Wellington Parade was built in 1924 on a site previously occupied by a single brick house. It was designed by architect Nahum Barnet for Walter Joseph Williams, a chemist who had previously rented premises on the opposite corner since c.1915. It was built as three shops on Wellington Parade, numbered 136, 138 and 140/4, and a spacious residence above taking up the whole of the first floor and part of the ground floor and entered off Powlett Street.

Williams used No. 140/4, on the corner, as his chemist shop. At the time this was one large shop but which has since been divided into two. The other two shops were leased out. He lived above. Williams remained the owner and occupier of the building until his death on 23 June 1954.

A year before his death, obviously realizing the business was getting beyond him, he leased the chemist shop to James Brice Pyman, the father of Andrew Pyman, who still runs a chemist shop further down Wellington Parade.

The Argus, on 13 October 1956, reported that ‘Real Estate agents buy their own very big office’. RESI paid £32,500 for it to use for its offices and headquarters, without needing replanning or structural alterations.

In about 1969 the building next door, a garage with flat above, came up for sale and RESI bought it and c.1973 demolished it and extended its original building in the same style.