About us

The ECO Group is a Cologne-based group of companies whose key capability is the optimisation of commercial real estate portfolios.

A dynamic and competent in-house team covers the areas of asset, property, and tax management, as well as the whole spectrum of technical facility services.

“Independent, responsible, efficient, dynamic, pragmatic and precise"

We are committed to bringing these adjectives to life. This is why personnel planning of our ECO Group teams is extremely important to us.

Ferdinand Stahl M.A.
Co-Founder & Chief Executive Officer

Team Member Skills

Eco Invest

  • Multi-tenant real estate portfolio in top locations

  • Doubling the properties’ value within 3 years

Our investment strategy focusses on the prime locations of the German office space market. We were able to double the value of the properties entrusted to us within 3 years. This appreciation is based on the significant increase of our portfolio’s rental income, and corresponding re-evaluations performed by banks.

We realise our results through strategic lease negotiations, a reduction of ancillary costs, and structural optimisations. Our achievements are possible thanks to strategic contributions by all teams of the ECO Group.

Office building near the Rhine / Cologne

Purchase price: EUR 4.5 million
Amount invested: EUR 800 K
Market value in 2019: EUR 9.0 million

Office building in Cologne-Lindenthal

Purchase price: EUR 7.8 million
Amount invested: EUR 200 K
Market value in 2019: EUR 12.0 million
Market value in 2023: EUR 16.0 million

Eco Facility

  • Many of our ECO facility managers are master craftspeople

  • Our ECO vehicles are mobile workshops, equipped with high-end tools

  • The software IX-Haus plus provides for a transparent overview, effective order acceptance, and quick handling of any damages

Our facility management vehicles are state-of-the-art workshops on wheels featuring first-rate tools (e.g. by HILTI) and sophisticated cleaning machines such as the i-Mop XL. This equipment is highly resource efficient, reducing the required working time while protecting the environment.

Modern tools combined with our facility managers’ technical know-how enable us to take care of small and medium-sized repair, modernisation, and maintenance jobs ourselves – quickly, flexibly, and at any time.

i-Mop XL

In practical use we have found the area performance to be 3 to 6 times greater than that achieved with two-stage wet mopping.

Smart, tough and built to last

The Hilti diamond coring tool DD 250

The diamond coring toll DD 250 by Hilti features a smart display designed to guide the operator during all types of coring jobs.


  • Operating costs are reduced by 20 to 30 %, thanks to energy monitoring paired with progressive and sustainable technology

Minimally invasive measures that require no capital investment enable us to reduce the operating costs of any building by up to 10 %.

Costs may even be reduced by as much as 20 to 30 %, if a weather module is used. The related investment costs are usually offset within four to six years.

Our ECO software system plays a central role, also when it comes to energy monitoring. ECO monitoring provides for energy consumption to be tracked, allowing for excessive electricity consumers to be identified and eliminated.

Weather module

Reduces operating costs by up to 30 %

Photovoltaic and solar systems

Energy-saving solutions

Eco Tax

  • Among the top 2 % of tax consultants working digitally in Germany

  • Specialist real estate tax consultants

  • Cost efficient – our tax consultants are also property managers. Double entries are avoided.

According to DATEV eG, we are among the top 2 % of German tax consultants working fully digitally. Our tax team of currently around 20 staff members comprises certified tax consultants for real estate taxation and property management (ISM / IFU gGmbH), as well as specialist consultants for international tax law.

The ECO Group’s full digitisation is reflected in a perfect integration of property management, tax and document management software. Our property managers are specialised real estate tax consultants and are authorised to transfer exemplary ancillary cost statements from the property management software directly to the tax office. This enables our customers to avoid additional costs due to double accounting or double entries.

Officially appointed tax consultants take responsibility for any tasks reserved for authorised professionals.

Eco Property

  • FM & PM are using multiple award-winning cloud-based software featuring a very high degree of automation

  • Digitisation of all ECO teams provides for a higher level of tenant satisfaction (IX-Haus, IX-Haus plus, DATEV, and DocuWare)

  • High degree of compliance

Computer Aided Facility Management (specialised CAFM software) facilitates the planning, documentation, and management of commercially used premises and real estate. We use state-of-the-art market-leading software (IX-Haus, IX Haus plus, DATEV, and DocuWare) to provide the basis for our high quality and performance standards.

The same cloud-based database is used by all teams of the ECO Group. We focus on digital

communication and workflows. The interface of our PM software (IX-Haus) allows for data to be transferred to the tax software (DATEV), rendering external accounting activities unnecessary. The supplementary ticket software IX-Haus plus provides for a transparent overview, effective order acceptance, and quick handling of any damages. In addition to this, it also improves digital monitoring of statutory deadlines, such as review and maintenance duties.

IX-Haus / IX-Haus plus

Triple award-winning cloud-based software with increased automation – IX-Haus / IX-Haus plus

DATEV Accounting

Market-leading accounting software environment


  • 30 years of cumulative experience in the area of construction projects (commercial and residential properties)

  • Planning and decision-making security

To support any upcoming decision-making processes, the ECO Group relies on an exclusive, comprehensive team of advisers with decades of experience.

The network of experts that are consulted as needed, comprises acclaimed personalities from the construction and construction-related industries. In addition to the expertise represented within the ECO Group itself, the network covers the following areas in particular:

Architecture, project planning and market analyses for the construction industry, strategic planning, trends and sustainability, consulting regarding new construction projects, financial analyses and profitability incl. for existing properties, as well as construction and administrative law.


Outstanding multiple award-winning architect and artist, and source of inspiration for our group’s philosophy


Architects and advisers of the ECO Group

Owners of VALENTYNARCHITEKTEN Planungsgesellschaft mbH and long-standing partners of Thomas van den Valentyn


Ferdinand Stahl M.A.

Co-Founder & Chief Executive Officer

Yosef Levy

Co-Founder & Director of Business Development

Jeanette Adametz

Office Manager &
Team Coordinator

Martin Tameh 

Technical Director

Marek Nieslony

Technical Manager

Thomas Haag

Dipl.-Kaufmann Certified Tax Advisor for Real Estate

Martin Manz 
Property & Accounting Manager

Elmar Kurth

International Tax Advisor

Diana Christensen

Property Manager

Ihre Kontakt Person

Ich beantworte Ihnen gerne Ihre Fragen. Kontaktieren Sie mich!

Jeanette Adametz

+49 2241 / 26671 – 25

Diana Christiansen

+49 2241 / 26671 – 11

Thomas Haag

+49 2241 / 26671-16

Martin Tameh

+49 170 / 4988855

Jeanette Adametz

+49 2241 / 26671 – 25