I wish to build a house over an existing depression (sump). The sump is required to remain as is with a suspended concrete slab constructed for the house to sit atop. Access needs to be maintained to the sump for inspections and machinery. Essentially a suspended concrete slab of appropriate thickness, supporting walls, footings (potentially piled footings). Approx 600mm of sand will cover the suspended slab and the house slab above that. I need preliminary section drawings and indicative wall / slab thicknesses for modelling purposes only. I will provide anticipated geotechnical information. Would suit an experienced structural engineer familiar with concrete design and Autocad.