Our success is based on our four core competencies:

Urban planning

The creation of development rights turns fields into valuable building land. However, such value creation is not based purely on the planning law expertise of the developer. The decisive factor for success is a serious understanding of the needs and concerns of the communities and responsible authorities. We know the expectations and concerns of the decision-makers and can estimate the prospects of success of our projects at an early stage.


The right architecture transforms “approved square meters” into demand-oriented apartments and offices. Our goal is to create compromises between economy and aesthetics that do not feel like compromises. Our in-house expertise also allows us to realistically assess construction costs as well as the risks of structural alteration in renovation projects.


The rapid availability of funds is a prerequisite for the acquisition of truly attractive projects. Thanks to our expertise in structuring bank and mezzanine financing as well as our well-established investor network, we can swiftly react to market opportunities and make binding commitments in a timely manner.

Risk management

The conscious handling of risks is a prerequisite for sustainable success in project development. Despite our many years of experience, we do not rely solely on our gut feeling. We break each project down into quantifiable risk categories and simulate thousands of possible processes using a Monte Carlo model developed in-house. This allows us to correctly assess risks that often appear too large or too small when viewed purely intuitively.

Why work with Onnen & Onnen?



What we offer is not the solution of partial aspects but the increase of your property’s value



We develop projects since 1998

Unternehmergeist 2

Entrepreneurial spirit

We gladly share your risks and offer our services on a success-fee basis



Creative contract design allows us to find the right form of cooperation for your project


As an owner-operated family business, we have a long term perspective. From experience and conviction we therefore feel particularly committed to two values:


We never only think of the next project but the one after that as well.


Trustful partnerships enable quick joint decisions, smooth processes – and a good night’s sleep. These qualities are invaluable, and that is how we treat them.