Client: UNITE The York Street project, developed by Cassidy Group, is a significant student accommodation development located in central Nottingham. The scheme comprises 472 ensuite bedrooms, arranged in a mix of 4-to 11-bedroom clusters and studio apartments. This £50 million development spans ten storeys and is strategically positioned near Nottingham Trent University, offering students easy access to both the university and city centre amenities. The project features extensive student facilities, including a gym, bike storage, and multiple social spaces such as outdoor courtyards, designed to enhance the living experience. Services we provided Civil & Infrastructure Engineering Geotechnical & Ground Engineering Ground Investigation & Land Quality Structural Engineering Our Role BWB provided structural and civil engineering services throughout the development, including redesigning the original foundation solution to accommodate constraints imposed by the cave system. We conducted a series of tests on the existing columns to verify their capacity to support the new structure, enabling us to reuse these columns and reduce the need for additional foundations. Mitigating risks Our team also developed a steel podium structure that could be supported by the existing columns, minimising ground loading and mitigating risks associated with the underlying caves. For the upper levels, we used a lightweight cold-rolled steel structure incorporating a cassette floor system, reducing the overall weight of the building and minimising the need for extensive sub-structure works. Existing cave system The primary challenge for this project was the extensive cave system beneath the building’s footprint. The initial design needed to be significantly modified to reduce the load on the ground and ensure the structure's stability. Our team conducted a series of structural assessments and load tests on the existing columns to verify their suitability for reuse. Constrained site Another challenge was working within a constrained city-centre site, surrounded by other buildings and infrastructure. We developed a detailed logistics plan to manage the delivery and installation of structural elements, minimising disruption to the surrounding area and ensuring the project remained on schedule.