Firm: possibly Rule Wynn and Rule

Address: 642 Hillcrest Avenue SW

Date: 1948

Status: demolished in April 2015

This house was one of two art deco houses the Hislop Construction Company built in Mount Royal in the late 1940s. The other is at 1102 Sydenham. Around 1973, the Hillcrest house was rebuilt substantially, at which time it lost its art deco elements. In 2015, Don Taylor demolished the house as well as its neighbour (638 Hillcrest) to built a new McMansion. The Sydenham house still stands, although it was altered substantially in the early 1990s.

There are plans for Hislop houses in both the Rule Wynn and Rule, and J. Stevenson archives. I haven't looked at either, so I don't know who designed which. The Rule plans appear to be lost.

https://searcharchives.ucalgary.ca/hislop-construction-company-residence