On 23 May 2018, the European Urban Agenda Housing Partnership organised a capacity building workshop on “State Aid and Affordable Housing Investments”. The aim of the event was to develop mutual understanding on how the prevailing legal uncertainty in state aid law creates obstacles for public investment in housing. It also sought to contribute to the development of knowledge on the use of state support in the housing sector in general and multi-story apartment buildings in particular. Speakers and participants from the legal field and affordable housing scene discussed how state aid regulations and/or guidance could be improved to increase the supply of affordable housing.