“Limiting global temperature increase needs demand-side actions and lifestyle changes", stated the IPCC in their Special Report on Global Warming of 1.5. Building construction and operation are key to solving the climate and ecological crises and central for enabling sustainable development. To enable the sustainable transformation of the built environment, it is crucial to meet climate targets for buildings. However, it was shown that current building practice struggles to provide housing within planetary boundaries. What is needed are strategies for reducing building-related environmental impacts while at the same time providing adequate spaces as the social foundation for a regenerative and distributive, circular economy, as outlined for example in the doughnut economics concept. Social innovation, for example in the form of alternative models for spatial production and ownership, can help implement the sustainable development goals, and support regenerative lifestyles and emission reductions in the emissions-heavy building sector. However, today’s real estate market hardly supports the development and realization of alternative housing models. In response, practice shows that innovative models of housing are often driven by the initiative of the (future) inhabitants. In this study, we investigate and analyze different models of social innovation in housing based on three recently completed building case studies in Austria. The case studies are situated in a broad range of spatial contexts: re-activating the countryside, vitalizing a newly developed neighborhood, or bringing new life to abandoned, existing buildings. They are showcasing strategies such as: innovative models of (co-)financing and (co-)ownership to provide affordable housing; the shared use of spaces, functions and resources for reducing environmental footprints. We provide insights as to how alternative housing projects are being established successfully, what models groups are exploring for governance, financing and ownership, and which other social innovation practices may support or enable the implementation of regenerative lifestyles.