Designed by John Burnet Parkin, a local architect, this school with each classroom featuring project areas with sinks, large windows and slide-along curtains and exit doors to the outside, set a pattern for new school design in the 1940s and 1950s. The architect realized a child's scale in the design of the school, resulting in lowered ceilings, blackboards, window sills and shelving. The official opening for the first section was in January 1943, followed by many visits by trustees and teachers from other areas and by stories in papers and journals here, in Great Britain and the United States. Parkin later designed many large modern public and commercial buildings for which he also received international acclaim.
The original Sunny Lea school opened in 1908 on the east side of Prince Edward Drive to serve rural Etobicoke School Section 14, which extended from the Humber River to Islington Avenue, between Bloor Street and Berry Road. It was a white brick, two-story, two-room building and served until 1945 because wartime conditions delayed completion of the new school. Edna G. Whitworth, a young pupil, received the prize for her suggestion of the name for the school, which was to become the name of the community.