Vienna's Dual Social Housing Model — Municipal Gemeindebau plus Limited-Profit Housing at City Scale

Vienna runs two parallel social housing pillars: municipal housing (Gemeindebau) managed by Wiener Wohnen, with roughly 220,000 flats, and limited-profit housing built by non-profit associations with public subsidy and rent regulation, with roughly 200,000 dwellings. OECD data cited in secondary sources put the combined social-housing share near 44% of the housing stock, with a broad income mix.
The City reports that social housing share varies by district from 10% (8th district) to 65% (11th district), and that THEWOSAN thermal renovation standards roughly halve space-heating energy use in renovated buildings, avoiding approx. 304,000 tonnes of CO2 annually (socialhousing.wien).
Caveats: much of the evidence is descriptive rather than causal; critics (e.g. AEI) argue the model depends on Vienna's historic land ownership, long-term subsidy and regulatory context, so direct transfer to other cities is uncertain.

Read the full analysis: https://climateandcommunity.org/research/vienna-green-social-housing/