We estimated the future need for judicial hearing rooms (courtrooms and judicial conference rooms) for Halton and Peel regions, both rapidly growing areas west of Toronto. One aspect of this assignment was to explore an option to have a proposed new courthouse in Halton serve some of the needs of neighbouring Peel. Our needs assessment for Peel was primarily to provide guidance for the design team addressing an addition to the Brampton Courthouse. Our analysis for Halton was for a proposed consolidated courthouse to replace the two existing deficient facilities. A key challenges in assessing future need for judicial hearing rooms in Peel was to estimate the level of ‘unmet demand’ in a courthouse that has been overutilized for several years. Another challenge for both locations was to estimate the supplementary need for judicial conference rooms for activities that were not consistently recorded. We concluded that by 2041 Peel would need 65 judicial hearing rooms, and Halton would need 26 judicial hearing rooms. Completed Peel in 2015 and Halton in 2016.