Trier/Stuttgart, Germany, April 28, 2025. Trier is the oldest city in Germany. It combines a university, bishop's seat and a UNESCO World Heritage site. Hence, it plays an important role in the region: through the construction of around 960 residential units – of which 159 single family houses and nearly 800 flats in apartment buildings – the city is now expanding its diversity and creating an attractive living environment on the site of the former Castelnau barracks. Covering an area of around 58 soccer fields, the site in the south of the city is being extensively remediated and developed by EGP GmbH Gesellschaft für urbane Projektentwicklung. Now under construction, this will result in a diversely structured neighborhood in a green environment. Under the name of ‘Castelnau Mattheis’ it is currently Trier’s largest new development area. In close collaboration with the administration of the city of Trier and Drees & Sommer, which specializes in advice on construction, real estate and infrastructure, EGP is thus making an important contribution to the building of urgently needed residential space in the region.

Housing construction in Germany has fallen sharply. Increased building costs, bureaucratic hurdles and a limited supply of space pose obstacles to development. According to a forecast of the German Property Federation (ZIA), the country is facing a shortage of about 830,000 apartments by 2027. The housing supply is low, especially in densely populated areas where demand is high[i]. Alternatives to traditional new constructions are needed to close the gap. An efficient and sustainable solution is the rezoning of available space. David Becker, Managing Director at EGP GmbH comments: "Redevelopment of brownfield sites provides an opportunity to counteract the increasing sealing of the soil surface and to use the potential that already exists – the first step towards a sustainable development.” And he adds: “Castelnau Mattheis benefits from its elevated location right next to the forest: green, natural surroundings with mature trees. So these are great conditions for a livable environment.“ The Castelnau barracks is one of five major urban development projects of EGP in Trier by which the city is responding to the increasing need for residential space. 

Grounds for the Future

Trier can look back on a long history as a military base. Up to 15,000 soldiers were stationed here at times, making the city the second-largest French garrison after Paris. Now only the French street names are a reminder of this past – the military facilities themselves have long since disappeared. Over a period of almost 25 years, the former barracks areas at the location have instead been gradually converted for civilian use – always in consultation with the local citizens and involvement of people in the planning activities.

The conversion of military land nonetheless poses particular challenges, as Max Vogel, Project Head and Leading Consultant of the Urban and Infrastructure Solutions division at Drees & Sommer, explains: ”A key issue is the clean-up of contaminated sites. For example, the ground of the Castelnau barracks’ former firing range had to be painstakingly cleared of ammunition remnants and pollutants.” But the effort has been worth it: "Where a shooting range used to be, a recreational area with a playground, soccer pitch and sunbathing lawn will be created in the next few years,“ says Drees & Sommer’s expert. 

Holistic Neighborhood Development: from Infrastructure to Open Space Design

In this project, the experienced specialist for neighborhood development services and his team are responsible for the development of the area in Trier, and thus the collaboration of the participating stakeholders in the project. This not only includes the basic planning and design of the district, in coordination with the city administration and EGP, but also responsibility for obtaining building rights and planning the cable and pipe infrastructure. An important aspect particularly in this regard is to coordinate the requirements of different project participants, i.e. the municipal utility company, planners, developers and clients. In addition to the choice of energy source (gas, geothermal or solar energy), the heating grid plan must also be defined, such as local or district heating. This is also where the decision is made on the telecommunications provider for the neighborhood, and how the sewer system should be designed. "A separation system is usually used nowadays: wastewater and rainwater are routed separately, ideally with decentralized infiltration of the rainwater in the district," says Max Vogel. In addition to the cable and pipe infrastructure, his team is also responsible for planning the roads, paths, neighborhood public spaces and playgrounds. They thus make a significant contribution to the sustainable redesign of the site. A total of 3.4 kilometers of new roads, 6.3 kilometers of sewers and 45 kilometers of pipelines are being built to make the district ready for the future.

Living Close to Nature with Urban Connections

The new development Castelnau Mattheis borders directly on the Mattheiser Wald nature reserve, a special location that is also incorporated into the neighborhood design. "An important issue for us is that development of the new residential district focuses on species conservation and the requirements of the adjacent natural space, and that the character of the landscape is transferred to the neighborhood," points out David Becker from EGP. For this reason, the planners opted for sustainable building materials, such as timber, and natural color schemes in shades of green and brown that blend harmoniously into the surroundings.

Despite its close-to-nature format, the neighborhood also offers optimal links to the surrounding area. A carefully designed mobility strategy and highly developed infrastructure ensure that distances are short within the neighborhood, while also providing easy access to neighboring districts and recreational areas. In addition, 21 commercial enterprises, a local shopping center and a daycare center create a high quality of life directly at local level.

A place where history meets with the future: Trier’s new residential district Castelnau Mattheis offers modern, sustainable living. A variety of housing types will be built at this location in five subareas by 2030, from detached homes to terraced houses and apartment buildings. “The first residents of the subarea Auf der Höhe have already moved in at the end of 2022 – an important  milestone for the project,“ comments David Becker.