Thomas Siebenhaar is a speaker and specialist in residential construction and building renovation/conversion. His central concern is the creation of affordable living space. He has been co-founder and managing director of Projekt Bauart WohnInvest GmbH since 2007 and is responsible for the strategic and operational management of eleven subsidiaries in the areas of project development and real estate management.

Since 2015, the focus of the group of companies has been on the construction of affordable housing and the development of the innovative Bauart 5D House. Projekt Bauart was awarded the Bavarian Innovation Prize 2024 for this concept; the development is also patented.

From 1998 to 2007, Thomas Siebenhaar worked for a general contractor for over nine years - including as sales manager and project manager for major renovation and conversion projects.

As a real estate economist, his current focus is on the planning, development and implementation of new residential construction projects in economically viable and socially sustainable structures.