From the outset we identified the groundworks required for these buildings as the biggest challenge. With each having a basement area the size of the property footprint – housing the kitchen, dining and family room, plus a lower-ground courtyard – this meant that not only was there significantly more surface material to remove, but also the adequate stabilisation of the substructure and the formwork needed for this was a major consideration. The site in Raynes Park was extremely tight, so precise logistics management was required to ensure that the lorries carrying excavated earth away arrived and left only as and when they were needed and that the manpower and machinery required to fill them were scheduled appropriately. Due to the scale of the basements we used a relatively new method of interlocking prefabricated steel formwork to create the basement shell, saving us time, reducing waste and increasing the precision of our work.