Wednesday, 19 November 2025
Sonar Development, the project development arm of the Sonar Group, has received building permits for the planned conversion of two vacant office properties in Eschborn into residential accommodation. The permits, covering the sites at Eschborner Hauptstraße 71–79 and 87, were granted without restrictions and within the statutory timeframe.
The project, undertaken on behalf of an institutional investor, will deliver around 200 residential units and contribute to addressing the region’s housing shortage. The development concept emphasizes sustainability, with the existing building structure retained to conserve embodied energy and reduce land consumption. Refurbishment work will target compliance with the KfW 55 energy-efficiency standard.
“The granting of the building permits marks an important milestone for our project,” said Steffen Wittwer, Managing Director of Sonar Development. “We would like to thank the entire planning team for their professional collaboration and the authorities – particularly the City of Eschborn, the Urban Planning Office and the Building Control Authority in Hofheim – for their timely processing. With this momentum, we are now entering the next phase of converting office space into contemporary housing.”
Sonar has appointed Ed. Züblin AG as main contractor for the project. “The conversion of existing buildings into modern housing makes an important contribution to sustainable urban development,” said Mark Simon-O’Sullivan, Project Director in Züblin’s Building in Existing Structures division. “We appreciate the trust placed in our expertise in transforming complex properties.”
Construction is scheduled to begin later in September.
