De VerbouwingsConstructeur produced the structural calculations for a villa in Zeist with a 5×8 m swimming pool in the basement. For the design of the basement slab 5 m below ground level, groundwater uplift plays a major role. The geotechnical consultant initially gave a conservative groundwater level, but after a critical review by De VerbouwingsConstructeur including a geohydrological assessment, it could be revised down by several metres. To prevent flotation, the basement slabs were given a 30 cm projecting toe. The soil above this toe loads the slab, as does the soil within the zone bounded by the angle of internal friction and the vertical plane at the toe. Thanks to this toe, the basement slab did not need to be made extra thick. The villa has curved thatched roofs at the front and side. The curved steel structure beneath them was analysed with a finite element program.
