In 1952 the then Nigerian Government invited the firm of W. H. Watkins Gray & Partners, to design a Teaching Hospital for Nigeria in Ibadan. As a result, an office was set up in Lagos, with work expanding to such an extent that a new independent partnership was created under the name of W. H. Watkins Gray Nigeria.
In 1972, young Nigerians were invited to join the partnership as part of an Enterprises Promotion Decree, established by the then government. It was decided, in view of the intentions of the Decree, that the name of the firm be changed to Interstate Architects to reflect a broader based thinking firm, working in all the states in the country.
The firm would later be incorporated as a Limited Liability Company in 1987, becoming known as Interstate Architects Ltd (IAL). The Company has accredited members of the NIA and registered members of ARCON.