Abstract

In an era of rapid urbanization, achieving sustainable urban development has become a critical global concern. Yet many regions continue to suffer from the negative repercussions of urban sprawl. Unlike many other environmental issues, urban sprawl is rarely addressed quantitatively, particularly in terms of proposing concrete solutions. This study aims to bridge that gap by first measuring the extent of urban sprawl across 111 planning regions and 16 federal states in Germany using the Weighted Urban Proliferation (WUP) method for the period 1995–2015. It then introduces and analyzes five future scenarios as a framework for proposing targets, limits, and warning values for urban sprawl as a strategy to manage it. The results show that (1) Urban sprawl in Germany increased by 51.67%, rising from 2.207 UPU/m² in 1995 to 3.348 UPU/m² in 2015, 7.2 times faster than the growth in the number of inhabitants and jobs (7.2%); (2) projected population trends (whether growth or decline) have a significant influence on setting reference values and determining the sustainability of future scenarios; (3) despite projected population declines in many regions by 2050, inaction—such as continued increases in land uptake per person, as in Scenario 1—will still lead to higher urban sprawl, which highlights the importance of urban form and extent of built-up area; and (4) strategies focused on densifying built-up areas can significantly reduce urban sprawl and represent a sustainable path forward. These findings and proposed reference values provide a solid foundation for future de-sprawling efforts in regional planning and serve as a quantitative reference framework for urban planners and policymakers.