This was a remarkable piece of engineering to create a spacious basement of 6000 sq ft beneath a house and its garden area in the exclusive St John’s Wood. The Metbase team used a Pynford concrete transfer slab supported by perimeter piling. The house was placed on ‘stools’ supporting the weight of the building while the Pynford slab was installed. The new space became a cinema, swimming pool, spa and accommodation. The remainder of the house received a thorough back-to-bare-walls upgrade and refurbishment.