Prof. Olusanya’s main research area is in the development of i) Urban housing prototypes focused on environmental comfort and energy savings in tropical climates ii) Building technology for large-scale  housing production based on sustainable industrialization tailored to the peculiarities of a developing economy. This has won several  awards and has been implemented in several projects notably i) The Unilag Experiment in Systems Housing (1992) – his official residence at the university ii) The Mass Housing Pilot Project for the proposed 1008 unit Housing Estate for Lagos Home Ownership & Mortgage Scheme (LagosHOMS) at Ijora-Badiya, Lagos (2016).

His pioneering traffic-gridlock trouble shooting concepts have been implemented, with notable successes in the Lagos mega-city i) The Onikan/Victoria Island link at the MUSON Center ii) Sheraton Hotel/ Police College return-loops at the Country Club junction, Ikeja (2013).

His major architectural projects include the 2500 capacity church auditorium of the RCCG City of David at Oniru Estate, Victoria Island, Lagos (2004), and the ongoing 3km by 3km Mega Auditorium of the Redeemed Christian Church of God at Redemption Camp, Ogun State, which on completion will be one of the largest covered space in the world.