Frankfurt am Main

Mertonviertel

An office and science district already turning residential, with rising office vacancy, low office rents and the city’s own housing company building there.

• About 650 flats and 700 townhouses already built; vacancy rising in larger office buildings
• B-Plan 922 (about 8.55 ha) replaces the demolished Lurgihaus with more than 1,000 flats by ABG and gsp Städtebau
• Office rents €12–15/m² (Cushman & Wakefield, mid-2026)

Risk: Some owners refurbish instead of converting, and parts of the area are zoned for commerce, where housing is not allowed.

Niederrad — Lyoner Quartier

Germany’s best-known office-to-housing district, steered for some 15 years by a landowner initiative and two B-Plans.

• B-Plans 872 and 885 provide for about 3,000 flats in the former Bürostadt
• Around 2007 about 30% of the Bürostadt’s offices stood empty
• We Live Tower (Lyoner Straße 14, 364 apartments) and livinit (Lyoner Straße 11, 375 micro-apartments)

Risk: Rents have risen to €16 and more per m², so entry prices are no longer low.

Bockenheim

The city is preparing existing buildings here for communal housing on Erbbaurecht, and a new quarter of about 2,000 homes reserves land for cooperatives.

• Former Akademie der Arbeit: concept procedure for communal housing on Erbbaurecht from autumn 2027
• Jordanstraße 3: city-owned since 2017 and largely empty for about five years by 2023
• Römerhof: about 2,000 homes with 15% of the land for communal and cooperative housing (B-Plan 946)

Risk: Timelines are long: interim uses at the Akademie der Arbeit are secured until at least 2031, and pre-empted houses may be re-privatised.

Westend and Bankenviertel towers

Defaulted towers and bank consolidation are emptying large buildings close to the centre.

• Trianon (about 68,000 m²): owning SPV insolvent, sale launched July 2025, about half vacant
• Commerzbank moves into the Central Business Tower from the end of 2028, leaving several complexes in Frankfurt and Eschborn
• Bankenviertel vacancy 110,800 m², of which 104,500 m² modern (BNP, mid-2026)

Risk: Towers tend to convert into high-end homes, and almost all Bankenviertel vacancy is modern space owners will try to re-let.

City of Frankfurt — existing-building concept procedures

The city hands buildings it owns or has pre-empted to communal housing projects by concept procedure on Erbbaurecht: Wittelsbacherallee 89 went to DachGeno RheinMain eG in February 2026, described as the start of a series; the Paradieshof tender carries up to €4.5 million of subsidy; the Akademie der Arbeit follows from autumn 2027. Ask for the next buildings in the series.

The 15% rule and reduced Erbbauzins

15% of the residential floor area each new B-Plan creates goes by concept procedure to communal and cooperative housing. The Erbbauzins can fall to 1% for a social, public-benefit use, and a start-up fund since early 2026 pays audit and coordination costs in the planning phase.

Insolvency administrators (Trianon, Altes Polizeipräsidium, Benchmark)

Administrator Stephan Laubereau (Pluta) is selling the Trianon on behalf of the insolvent owning SPV. Gerch’s insolvent project companies hold the Altes Polizeipräsidium, where the creditor banks were due to choose in early 2026 between waiting and a quick sale. Benchmark Real Estate GmbH has been insolvent since August 2025. Administrators are the sellers’ representatives and can be approached directly.

Protestant church (EKHN) and the Catholic diocese of Limburg

The EKHN deanery sorts its buildings into categories A, B and C (C = no long-term use) with synod decisions in December 2026 and a 35% cut in building funding from 1 January 2027. The diocese of Limburg is giving up St. Christophorus in Preungesheim. Offer an Erbbaurecht alternative before demolition.

Land Hessen land fund

The Land put €60 million of the Polizeipräsidium sale proceeds into a land fund that leases land to developers committing to at least 50% subsidised housing — a fit for a cooperative that builds to that standard.

BImA, through the city’s first-refusal right

BImA’s commercial portfolio in Hessen was 57% empty on 1 January 2026; its 2023 list names vacant offices at Hansaallee 24–26 and Kaiserkronenweg 1 and the Lötzener Straße estate. The €35,000 discount per social flat also works on Erbbaurecht and can be passed on to a cooperative via the city.

KfW 266 "Gewerbe zu Wohnen" (federal)

Since 1 July 2026: 30% of eligible costs, up to €30,000 per new flat, for converting offices, shops and similar buildings; Effizienzhaus 85 EE and 10 years of residential use. Apply before signing a construction contract; cooperatives are not named explicitly among applicants, so check the KfW Merkblatt.