Toomath's work reflects an exploratory and intelligent engagement with modernist architectural ideas. A key architectural interest was the articulation of continuous space, which is particularly evident in his Toomath Senior house, Lower Hutt (1949), and the Mackay house, Silverstream (1961). The Toomath Senior house is famous as the site of a discussion Toomath and Lew Martin had with architectural historian Nikolaus Pevsner about New Zealand construction. Pevsner found the detailing of a post in the carport unrefined. Toomath argued that it reflected an honesty in detailing, relevant to New Zealand architecture. The Mackay House, Silverstream is symmetrically planned and was designed for a couple without children. It was awarded the New Zealand Institute of Architects (NZIA) Bronze Medal in 1962.