Material passports have been proposed to collect, store, and share material information to promote circularity in the construction sector. However, the current recommendations for material passports focus on material information at a building scale with little attention to its implications on a city scale. To address this limitation, this paper provides directions for developing a material passport ontology that could be used to collect, store, share, and retrieve data at multiple scales of abstraction. It describes the requirements for a material passport ontology and provides recommendations for integrating existing ontologies. This paper is relevant to researchers developing information management platforms to enable a circular economy