The SusCity project, an MIT Portugal project, falls within the scope of smart cities. One of its tasks aims to research and develop metadata artefacts to be used in the scope of a Linked Open Data platform for the project’s data. In this article, we report the process and results associated with the development of the following metadata artifacts: an application profile, a metadata schema and four controlled vocabularies, one of which is independent of the application profile. The application field is the certification of the energy efficiency of buildings. For the development of the application profile, we inspired ourselves in the Me4MAP method although we did not use it thoroughly. The creation of the metadata schema and controlled vocabularies was resorted to the use of wikidata, so all new terms (properties and concepts) are wikidata terms. The results include the application profile, the metadata schema and the controlled vocabularies, and are all already open to the community for use and reuse. The application profile has 11 properties, four of which are new. The controlled vocabulary on measures for energy efficiency has 22 new terms spread over four­­­ levels. Information about all new terms will be included in the Linked Open Vocabularies service.