Densification and Housing Policy – Vertical Extensions as a Response to Housing Pressure and Limited Land Availability

I investigate vertical extensions (VE) as a potential instrument of housing policy and urban densification. Many European cities face increasing housing demand while the availability of land for new development is limited. At the same time, a significant part of the existing housing stock consists of low- and medium-rise buildings that may offer additional development potential above their current roof level. My research examines whether vertical extensions can contribute to increasing the housing supply without requiring new land for construction. In this context, VE is considered a form of urban densification that makes more efficient use of existing buildings, infrastructure, public transport, and services. It may therefore support compact city principles and help reduce pressure for further urban expansion. I've analysed Polish context, using data from the national register of building permit applications and decisions. Data collected for the period 2016–2025 make it possible to examine the scale and geographical distribution of vertical extension projects in Polish regional capitals. The analysis also distinguishes between different building types, including single-family, multi-family, service, and public buildings.

I'm also an author of the VE3PBAC methodology, a Three Phase Assessement Criteria for identifying buildings suitable for vertical extension through legal, planning, urban, and technical apcets.

The broader objective is to determine under what conditions vertical extensions can become a more systematic element of housing and urban policy. Rather than treating VE as an individual architectural intervention, the research considers it as part of a wider strategy for increasing housing capacity, regenerating existing building stock, and limiting land consumption. This approach is consistent with the principles of the compact city, sustainable urban development, the EU Renovation Wave, and the New European Bauhaus.