A two-storey residential building is to be constructed on a riverside plot (protected by a river wall) in South Downs, East Sussex. The ground consists of a top 0.1m dark grey spongy-like soil over 3.9m thick made ground, overlying a 5m-thick river alluvium layer (granular sand and gravel) on chalk bedrock. The alluvium layer contains a lenses of silty soils which seems to be loess. A plan view of the site and a longitudinal cross section through the site are illustrated in Figure Q4. The residential building is shown as Block H on the plan drawing. With proper reasoning, recommend a foundation solution (shallow or pile) and comment on the possible design/construction challenges.