Leistbares Wohnen in Graz: Politikoptionen, Wirkungen und Rolle gemeinnütziger Bauträger

The report Leistbares Wohnen in Graz: Politikoptionen, Wirkungen und Rolle gemeinnütziger Bauträger is an evidence‑based analysis commissioned by the Österreichische Wohnbaugenossenschaft (ÖWG) and produced by EcoAustria in May 2026. Authors Wolfgang Schwarzbauer, Monika Köppl‑Turyna and Sarah Rabong, all researchers at EcoAustria, examine how affordable housing can be expanded in Graz through rent caps, municipal building and non‑profit housing developers (GBV). The study combines demographic trends, market data and input‑output modelling to assess fiscal and regional‑economic impacts.

Between 2010 and 2024 Graz’s population grew by roughly 18 %, and projections indicate a further increase of about 11 % by 2025. Housing demand therefore outpaces supply, while construction permits have been falling since 2020. Building costs and financing conditions have risen, leading to higher rents in both rental and ownership segments. The study notes that private developers and GBV together added about 40 % and 40 % respectively to the housing stock from 2011 to 2023, but overall supply remains insufficient.

Three main instruments are compared:

1. Mietobergrenzen (rent caps) – provide short‑term relief for existing tenants but are shown to dampen private investment, reduce mobility and ultimately shrink long‑term supply. Empirical evidence indicates a 9.4 % average reduction in regulated rents, while unregulated rents rise by about 4.8 %.
2. Kommunaler Wohnbau (municipal housing) – allows the city to build directly but is financially strained. The municipal housing company Wohnen Graz recorded a loss of €5.5 million in 2025 despite a €3 million subsidy, with a €49.8 million overdraft on its main account. The city’s high debt level makes large‑scale public building fiscally risky.
3. Gemeinnütziger Wohnbau (non‑profit housing) – operates under a cost‑coverage principle, reinvesting surpluses and avoiding direct public expenditure. An increase of 10 percentage points in GBV share of the unregulated market reduces rents by €0.30‑€0.40 per m². The sector generated €466 million of investment in 2024, producing €351 million of added value and 4 163 full‑time jobs nationwide; 45 % of these effects are concentrated in Styria.

The study’s input‑output analysis shows that each euro of public housing subsidy triggers €3‑4 of total investment in the GBV sector (lever ≈ 3.3). Consequently, €1 of public funds yields €1.15 of regional value‑added, whereas the same €1 spent directly by the municipality would generate only about €0.35 of regional impact. This demonstrates the superior fiscal efficiency of supporting non‑profit developers.

Adjusting allowable building density in the land‑use plan is highlighted as a cost‑neutral lever. Current density limits of 0.6 permit roughly eight units on a 1 000 m² plot; raising the limit to 1.2 or 2.0 could increase potential units to 17 and 28 respectively, more than doubling or tripling supply without additional public spending. The study points to the Graz‑Reininghaus redevelopment as a successful example of higher density planning.

The authors propose five coordinated actions:

1. Systematically review and raise building densities where feasible.
2. Actively support GBV by providing suitable land, streamlined zoning and reliable funding frameworks.
3. Prioritise the financial overhaul of Wohnen Graz before considering new municipal construction.
4. Apply rent caps sparingly and monitor their market effects closely.
5. Recognise housing investment as an economic stimulus, leveraging the high multiplier effect of GBV‑led projects.

In 2024, GBV investment in Styria generated €392 million of production, €163 million of regional value‑added and 1 864 jobs. The sector’s multiplier effect makes it one of the most efficient public‑investment tools for sustainable urban development, aligning social affordability goals with strong economic returns.