Analysen und Empfehlungen zur Vereinbarkeit von bezahlbarem Wohnen und Klimaschutz

The report “Analysen und Empfehlungen zur Vereinbarkeit von bezahlbarem Wohnen und Klimaschutz” is an online publication (BBSR‑Online‑Publikation 87/2024) issued by the Bundesinstitut für Bau‑, Stadt‑ und Raumforschung (BBSR), the federal research institute for building, urban and regional development in Germany. It was prepared under the “Allgemeine Ressortforschung” program for the Federal Ministry for Housing, Urban Development and the Building Sector (BMWSB). The authors include Katja Schumacher, Johanna Cludius, Malte Bei der Wieden, Veit Bürger, Katja Hünecke, Sibylle Braungardt, Viktoria Noka, Victoria Liste and additional experts from the Öko‑Institut and the Institute for Ecological Economics (IÖW). The study investigates the conflict between affordable housing and climate protection in the German building sector and proposes policy recommendations.

Three clusters of policy instruments are examined: (1) CO₂‑pricing and revenue redistribution, (2) “Fordern und Fördern” (mandatory standards combined with targeted subsidies), and (3) complementary measures such as energy‑performance certificates, heating optimisation, smart‑building technologies and a climate component in housing benefits. The CO₂‑price scenarios use 80 €/t CO₂ (2025 level) and 155 €/t CO₂ (2030 level). Redistribution options include a flat climate dividend (70 €/person or 100 €/person) and several socially‑tiered variants that allocate higher payments to lower‑income deciles.

Modeling with the WIRPOL, Mod‑Umlagen and SEEK tools estimates that the CO₂‑price generates annual state revenue of €10.2 bn at 80 €/t and €13.3 bn at 155 €/t. Climate‑dividend costs range from €2.6 bn to €6.4 bn depending on the design. For the lowest income decile, the net effect is an entitlement of €70–105 €/person per year, offsetting CO₂‑costs that represent 0.5–0.7 % of disposable income. Higher deciles experience modest burdens (up to 0.6 % of income) or slight net gains with the flat dividend.

The analysis distinguishes between renters, self‑occupied owners and private landlords. Renters typically bear CO₂‑costs through the staged cost‑allocation model, sharing them roughly 50 % with landlords. Modernisation‑related rent increases are capped at 8 % of renovation costs, with a monthly ceiling of €3 / m² (or €2 / m² for low‑rent apartments). The “third‑model” proposal suggests a 10 % cost‑pass‑through combined with mandatory uptake of subsidies, potentially reducing the rent impact. For owners, CO₂‑costs are fully internalised, but subsidies (e.g., 30 % of heating‑system investment via the BEG programme) improve economic viability, especially for heat‑pump installations.

The 65 % renewable‑energy requirement for new heating systems (effective from 2024) and minimum energy‑performance standards (MEPS) are projected to generate significant CO₂ reductions while delivering average heating‑cost savings of 20–30 % for compliant buildings. The study notes that a 65 % renewable‑energy share, coupled with BEG subsidies, yields a positive net present value for most residential retrofit scenarios, provided that fuel prices remain at or above current levels.

Socially tiered climate dividends are shown to protect the most vulnerable households more effectively than a universal payment. Variant II (higher payments to the first two deciles, moderate payments to the next four) reduces net burdens for the bottom two deciles to below 0.2 % of income, while keeping fiscal costs manageable. The report recommends that remaining CO₂‑revenue be allocated to climate‑social funds, energy‑efficiency grants for low‑income owners, and targeted rent‑control mechanisms.

The study emphasizes that the regulatory framework (building code, heating‑plan law, CO₂‑cost‑allocation law) provides the necessary legal basis for the proposed measures. It calls for coordinated action among federal ministries, state governments, housing associations and private landlords. Monitoring mechanisms should track CO₂‑emissions, housing‑cost burdens and the uptake of subsidies to adjust policies iteratively.

1. Strengthen the legal basis for CO₂‑pricing and ensure transparent, income‑adjusted redistribution.
2. Adopt the 65 % renewable‑energy heating requirement nationwide and link it to BEG subsidies.
3. Introduce a “third‑model” of modernisation‑cost allocation that obliges landlords to use subsidies before passing costs to tenants.
4. Expand the climate component of housing benefits and target energy‑efficiency grants to low‑income owner‑occupiers.
5. Promote complementary tools (energy certificates, smart‑building tech, personalised energy advice) to increase acceptance and effectiveness. Overall, the publication provides a data‑driven roadmap for aligning affordable housing with Germany’s climate‑neutrality target for 2045, offering insights that are relevant for policymakers, housing providers and sustainability advocates across Europe.