The need to preserve the tent-like concrete roof of London's former Commonwealth Institute as the rest of the 52-year-old building was razed turned an adaptive-reuse project into a structural balancing act. With internal demolition temporarily undermining all but one roof support, the thin-shell, hyperbolic-paraboloid cover stands, thanks to an elaborate system of aids.
Work on the future home of the Design Museum is further challenged by the need to dig down 5 meters for an 8-m-deep basement. The below-grade expansion undermined much of the foundation.