Stefan Frey AG
Stefan Frey AG is a founder-owned, Cologne-based real estate developer and portfolio holder with ~€2 billion in completed project volume and ~2,500 residential units delivered across Köln and the Rheinland region. It operates a vertically integrated group spanning development, in-house sales, facility management, and district heating, serving owner-occupiers, buy-to-let investors, and municipal partners.
- Company typePrivate
- Founded1997
- HeadquartersKöln-Marienburg, Germany
- Headcount11–50
- GTM typeB2B and B2C
- OfferingServices
What Stefan Frey AG does
Stefan Frey AG (legal name: Stefan Frey Immobilien-Projekt-Management AG) is a Cologne-based, founder-owned real estate group operating as a developer (Bauträger), project developer, portfolio holder, and investor, with all shares held by founder Stefan Frey. Founded in 1997, the company has cumulatively completed projects with a total volume of approximately €2 billion, delivering around 2,500 residential units of which roughly 70% are row houses, primarily in Köln and the broader Rheinland/NRW region.
The business is vertically integrated across the full real estate value chain through wholly-owned subsidiaries: INTERHOUSE GmbH handles in-house sales and marketing of new developments; Rent-On! provides district heating services using BHKW cogeneration at student housing properties; and S.O.S. GmbH delivers facility management for the owned portfolio. The "Plug & Study" sub-brand supplies fully furnished, all-inclusive micro-apartments for students and trainees. The company offers Erbbaurecht (hereditary building rights) as an alternative ownership model and markets apartments under the new 5% depreciation (AfA) regime for buy-to-let investors.
Revenue is generated through three streams: one-time unit sales from project development and trading (Bauträgergeschäft), recurring rental income from a growing own portfolio (1,111 rental units, 144,048 m², 1,670 parking spaces as of January 2026, projected to grow to 1,450 units by 2026/27), and transaction fees flowing through INTERHOUSE. Go-to-market is sales-led, combining the captive INTERHOUSE channel for end-buyer absorption with direct executive engagement for institutional co-investment and municipal partnerships (e.g., KD Stadtsanierungsgesellschaft Aachen). The company is expanding its recurring-rental base, including a January 2026 joint acquisition of a 300-unit Bergisches Land portfolio with Bonum GmbH and Melio Real GmbH.
Stefan Frey AG firmographics
Firmographics- Name
- Stefan Frey AG
- Legal name
- Stefan Frey Immobilien-Projekt-Management AG
- Website
- https://frey-ag.de
- Company type
- Private
- Founded year
- 1997
- Operating status
- Operating
- Headcount range
- 11–50 employees
- Short description
- Stefan Frey AG is a founder-owned, Cologne-based real estate developer and portfolio holder with ~€2 billion in completed project volume and ~2,500 residential units delivered across Köln and the Rheinland region. It operates a vertically integrated group spanning development, in-house sales, facility management, and district heating, serving owner-occupiers, buy-to-let investors, and municipal partners.
- Ownership category
- akta.pro rank
Stefan Frey AG industry classification
Industry- Product category
- Real Estate Development
- NAICS
- Residential Property Managers (531311), New Housing For-Sale Builders (236117), Offices of Other Holding Companies (551112)
- SIC
- Operators Of Apartment Buildings (6513), Lessors Of Real Property, Nec (6519), Investors, Nec (6799)
- akta.pro primary industry
- Residential Real Estate Asset Management (BPAJAMAA)
- akta.pro secondary industry
- Multifamily (Apartment) Property Management (BPAJAGAD)
Keywords
Where Stefan Frey AG is headquartered
LocationHeadquarters
- HQ city
- Köln-Marienburg
- HQ country
- Germany
- HQ region
- Europe
Offices1 record
Markets served
Stefan Frey AG business model
Business model- GTM type
- B2B and B2C
- Offering type
- Services
- Cost components
- Personnel, Operations, Supply Chain, Marketing or Sales, Infrastructure
Revenue model
- Real Estate Development & Trading (Bauträgergeschäft): The company develops and sells new-build residential units (apartments, row houses, semi-detached houses) as a developer and property trader. Completed project volume exceeds approximately €2 billion, encompassing ~2,500 residential units. Revenue is generated through one-time unit sales to owner-occupiers and buy-to-let investors. The company also offers Erbbaurecht (hereditary building rights) as an alternative acquisition model.
- Portfolio Rental Income (Bestandshaltung): The company holds a substantial own portfolio of residential and commercial properties generating recurring rental income. As of January 2026: 1,111 rental units, 144,048 m² of rental space, 1,670 parking spaces, with a projected increase to 1,450 units and 159,092 m² by 2026/27. Average net cold rent of €9.55/m² per month including parking.
- INTERHOUSE GmbH — In-House Sales Subsidiary: The company's proprietary sales subsidiary markets its own real estate developments. Revenue flows through commissions and sales fees generated from property transactions.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Subscription | Monthly | Portfolio rental — average net cold rent across all units |
Go-to-market motion2 records
Distribution channels2 records
Marketing channels4 records
Stefan Frey AG product offering
Product offeringCore offering
Stefan Frey AG is a vertically integrated real estate group that develops, sells, holds, and invests in residential and commercial properties primarily in Köln and the Rheinland region. The company delivers new-build apartments, row houses, semi-detached houses, office properties, student housing, and subsidized housing under brands such as Plug & Study, and operates an in-house sales subsidiary (INTERHOUSE GmbH), facility management (S.O.S. GmbH), and district heating services (Rent-On!). It also offers Erbbaurecht (hereditary building rights) as an alternative acquisition model and 5% depreciation properties for capital investors.
Product overview
Stefan Frey AG is a diversified real estate company operating as a property developer, real estate developer/trader, property holder, and investor. The company delivers services through integrated subsidiaries: INTERHOUSE GmbH (in-house sales and marketing), Rent-On! (district heating services), and S.O.S. GmbH (facility management). The core offering spans project development from concept to completion, management of a substantial property portfolio (144,048 m² rental space as of January 2026), and equity participations in residential, educational, and retail developments. The company also operates the PLUG & STUDY sub-brand for fully furnished student micro-apartments with all-inclusive rental packages.
Differentiator
Problem solved
Functional benefit
Brands
- Plug & Study: Brand for fully furnished micro-apartments for students and people in vocational training, offering all-inclusive rent.
Products and services
- Projektentwicklung / Bauträgergeschäft (Real Estate Project Development)
Quantifiable outcome
- Over €2 billion in project volume completed
- +4 more outcomes
Companies that use Stefan Frey AG
Customer profileNamed customers1 record
Segments4 records
Ideal customer profiles4 records
Stefan Frey AG technology and API
TechnologyTechnology focussed No
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Feature1 record
Stefan Frey AG partnerships and signals
Strategic signalPartnerships
14 partnerships are on record, tiered major, core and minor.
- Bonum GmbHmajorCo-investor alongside Stefan Frey AG and Melio Real GmbH in the acquisition of a residential portfolio with 300 units in the Bergisches Land region (January 2026 press release).
- Melio Real GmbHmajorCo-investor alongside Stefan Frey AG and Bonum GmbH in the acquisition of a residential portfolio with 300 units in the Bergisches Land region (January 2026 press release).
- INTERHOUSE GmbHcoreWholly-owned sales subsidiary of the Stefan Frey AG group. Responsible for marketing and selling all new development projects of the group. Directs prospective buyers to the group's real estate projects. Website: www.interhouse.de
- Rent-On! GmbHcoreIn-house heating service provider (Nahwärmespezialist / district heating specialist) serving the company's own real estate portfolio. Provides efficient heating solutions using BHKW technology at student housing properties.
- S.O.S. GmbHcoreFacility management service company (Servicegesellschaft) of the group, handling property management and maintenance for the group's own portfolio.
- Markona WohnungsGmbHcoreJoint venture entity for the Markona Wohnpark development in Köln-Neuehrenfeld and Köln-Ehrenfeld. Stefan Frey AG co-develops residential units (76 units in Markona II; 18 units in Winston III) through this entity.
- KD Stadtsanierungsgesellschaft AachencoreMunicipal urban development company acting as co-developer/bauherr (client) for the award-winning 'Studentisches Wohnen am Lousberg' project at Nizzaallee 34, Aachen. The project delivered 115 apartments for 157 students.
- Parkona AGcoreJoint venture entity for the Parkona Wohnpark development in Köln-Bilderstöckchen (159 owner-occupied apartments, 119 row houses). Logo appears in the partner network section of the company website.
- pbs architekten Planungsgesellschaft mbHmajorArchitecture firm for the award-winning 'Studentisches Wohnen am Lousberg' project in Aachen. Architects for the project that received the 2025 Auszeichnung vorbildlicher Bauten in NRW.
- CastleHomes GmbHminorPartner company listed in the company's partner/network section. Nature of partnership not specified.
- Educia GmbHminorPartner company listed in the company's partner/network section. Nature of partnership not specified.
- Conkav GmbHminorPartner company listed in the company's partner/network section. Nature of partnership not specified.
- TWL GruppeminorPartner company listed in the company's partner/network section. Nature of partnership not specified.
- RheinBauLand GmbHminorPartner company listed in the company's partner/network section. Nature of partnership not specified.
Scale indicators6 records
Recent moves6 records
Expansion highlights5 records
Stefan Frey AG competitors and assessment
Company assessmentBroad incumbents
- Vonovia SE: Europe's largest residential real estate company operating across Germany with significant NRW exposure; relevant as the dominant incumbent whose pricing, rental trends, and capital markets behavior set the backdrop for Frey AG's portfolio economics.
- Deutsche Wohnen SE: Large German residential property owner and developer, now part of Vonovia; relevant incumbent comparable for portfolio management practices, rental strategy, and capital markets dynamics affecting Frey AG's Bestandshaltung business.
Direct peers
- Quantum Immobilien AG: German project developer and investor with strong presence in NRW and student/affordable housing exposure; comparable to Frey AG's mix of project sales and long-term portfolio holding.
- Pandion AG: Cologne-headquartered residential real estate developer with a comparable focus on high-quality urban residential projects in NRW; directly competes for the same development sites, capital-investor buyers, and project partners as Stefan Frey AG.
- Bauwens GmbH & Co. KG: Established Cologne real estate developer with deep NRW roots specializing in residential project development, historic renovation, and mixed-use urban quarters; directly comparable in city focus, product mix, and developer-trader model.
- CG Gruppe AG: Berlin-based German residential and commercial developer active across multiple cities including NRW; comparable as a mid-large German developer-trader pursuing integrated development with both project sales and portfolio holdings.
- Instone Real Estate Group SE: Frankfurt-listed German residential developer with comparable focus on new-build apartments and project development for owner-occupiers and buy-to-let investors; similar project lifecycle and buyer segments make it a strong listed comparable.
Regional players
- LEG Immobilien SE: One of Germany's largest listed residential property owners with deep concentration in NRW; directly comparable to Frey AG's Bestandshaltung arm given shared geography, residential focus, and similar tenant base, though at vastly larger scale and publicly listed.
- Vivawest GmbH: NRW-focused residential property owner and developer jointly held by RWE and several NRW municipalities; comparable as a regional large-scale residential operator and publicly-subsidized housing developer in Frey AG's core geography.
Others
- Bonum GmbH: Co-investment partner with Frey AG and Melio Real GmbH on the January 2026 300-unit Bergisches Land portfolio acquisition; ecosystem participant rather than competitor, illustrating the JV partner archetype.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat6 records
Key risks6 records
Key highlights7 records
Customer concentration
Stefan Frey AG social profiles
Digital presenceStefan Frey AG financial estimates
Financial estimateRevenue estimate
Valuation estimate
Stefan Frey AG leadership team
Management profileNumber of profiles
Profiles6 records
Stefan Frey AG subsidiaries and ownership
Company hierarchySubsidiaries4 records
Stefan Frey AG funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Stefan Frey AG M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Stefan Frey AG
What does Stefan Frey AG do?
Stefan Frey AG is a vertically integrated real estate group that develops, sells, holds, and invests in residential and commercial properties primarily in Köln and the Rheinland region. The company delivers new-build apartments, row houses, semi-detached houses, office properties, student housing, and subsidized housing under brands such as Plug & Study, and operates an in-house sales subsidiary (INTERHOUSE GmbH), facility management (S.O.S. GmbH), and district heating services (Rent-On!). It also offers Erbbaurecht (hereditary building rights) as an alternative acquisition model and 5% depreciation properties for capital investors.
Is Stefan Frey AG a public or private company?
Stefan Frey AG is a private company. It is classified as founder individual operated bootstrapped and is currently operating.
When was Stefan Frey AG founded?
Stefan Frey AG was founded in 1997. It employs 11 to 50 people.
Where is Stefan Frey AG based?
Stefan Frey AG is headquartered in Köln-Marienburg, Germany, in the Europe region.
How does Stefan Frey AG make money?
Three revenue lines are on record. Real Estate Development & Trading (Bauträgergeschäft) is the primary driver. The others are portfolio Rental Income (Bestandshaltung) and INTERHOUSE GmbH — In-House Sales Subsidiary.
Who are Stefan Frey AG's main competitors?
Broad incumbents on record are Vonovia SE and Deutsche Wohnen SE. Direct peers are Quantum Immobilien AG, Pandion AG, Bauwens GmbH & Co. KG, CG Gruppe AG and Instone Real Estate Group SE. Regional players are LEG Immobilien SE and Vivawest GmbH. Bonum GmbH is listed as an others.
Does Stefan Frey AG have an API?
No public API is recorded for Stefan Frey AG.
What industry is Stefan Frey AG in?
Stefan Frey AG's product category is Real Estate Development. Its primary akta.pro industry code is BPAJAMAA, Residential Real Estate Asset Management, with a secondary code of BPAJAGAD, Multifamily (Apartment) Property Management. Its NAICS code is 531311 and its SIC code is 6513.