Valentine Gunasekara began his architectural career as a partner in 1959 alongside the Sri Lankan architect Geoffrey Bawa in Edward, Reid and Begg (ER&B).
Valentine considered that the spatial progression of a building at the boundary, where inside meets outside, is something that has to be more fluid, and this was achieved by raising the canopy or the roof edge up to ensure the outward draw.
He also contributed greatly to transforming Roman Catholic chapel architecture for new forms of congregation, and away from axial arrangements as advocated for by the Second Vatican Council.
Valentine Gunasekara's architectural contribution can be understood in three ways: He was in constant quest for new spatial concepts that could be created with the innovative technology and material of the time such as glass and reinforced concrete and was keen to familiarize local masons in handling sophisticated processes so that they could in turn expand their capacity.
His portfolio consists of a number of domestic buildings that reinterpreted Modernism for the tropical climate and setting, in particular inspired by examples from southern California.