Résumé : The “Future of Brussels” survey was managed by the Policy Lab. The Policy Lab is the service provider appointed by the Brussels government to design, organise and run the General Assembly of Brussels Local Authorities, “aimed at tackling, without taboos, the recurrent questions relating to the organisation of the city boroughs, PCSWs, police areas and the Region”.The General Assembly is organised in three complementary phases:1) A broad-based consultation of the Brussels population by means of a survey (Phase 1)2) Institutional debates with a range of actors (Phase 2)3) Meetings with citizen (Phase 3)The “Future of Brussels” survey corresponds to Phase 1 of this process. It was coordinated by Justine Brunet, Robin Lebrun, Aurélie Tibbaut and Emilie van Haute (Policy Lab, Université libre de Bruxelles [ULB]).The survey planned was 20 minutes long and consisted of closed questions only. It was designed (1) to ask citizens’ opinion about the functioning of their institutions and the institutional problems they face (assessment of the existing situation), (2) to identify citizens’ priorities among the topics and challenges approved by the Government, and (3) to outline preferences for improving the quality, efficiency and equity of public service, the clarity of institutions, the accountability of the policies implemented and the participation of citizens in public decision-making.The codebook sets out the methodology and questionnaire used for the “Future of Brussels” survey.