This article presents the findings of a fidelity assessment conductedwith a Housing First programme in Canada that supported clients with problematic substance use. A mixed-methods (quantitative and qualitative) evaluation design was used. A fidelity assessment survey, fidelity rating conciliation session, and interviews were conducted with programme staff and management to identify facilitators and barriers to the programme’s fidelity to the Housing First model.

Data analysis identified areas of high and low fidelity originating at systemic, organizational, and individual levels, with an overall high level of fidelity found. Factors supporting fidelity included the availability of government-funded rent supplements and organizational commitment to the principles of Housing First. Factors limiting fidelity included a lack of affordable housing and limited client and peer involvement in programme decision-making.

Programme adaptations implemented for local relevance were also identified, including a novel programme partnership between two community agencies that helped to partition the delivery of housing services from support services. Implications of the results both locally and globally are discussed.

This journal is open-acess.