The project, a straightforward rear extension to a semi-detached house, presented a unique challenge due to the site being situated on a watercress marshland. Traditional trench foundations were unsuitable for this type of land. In response to this challenge, an innovative approach was taken, avoiding the need for piled foundations.

Instead of opting for a piled suspended reinforced concrete (RC) slab, the design introduced a constant thick RC raft slab. This raft slab was reinforced with mesh rebar, providing the necessary structural support for the extension while addressing the specific challenges posed by the marshland. This strategic design not only accommodated the site conditions effectively but also resulted in cost savings for the client by eliminating the need for piled foundations.