Hi5 homes not only refer to luxury and home automation and other features, these are typically structurally also very strong and the life of the building is much longer than a normal building.
Raft foundation: A foundation (usually on soft ground) consisting of an extended layer of reinforced concrete is called a raft foundation.
The advantages of a raft foundation are that it distributes the loading from a building relatively evenly over the footprint of the building and also minimises differential settlement of the columns.
For any building, the first need is to work out the maximum pressure and ensure that the clay can safely take this concrete filling without undue settlement. Then you dig down to the formation (if there are no basements, this should be at least 1.5-2 m below ground level depending on local conditions), place around 75mm of blinding/weak concrete, over which you may need to apply waterproofing, over which you put some protection boards, over which you place the rebar, then put up formwork around the perimeter and pour in the concrete.
For thick rafts you will need to control the heat of hydration for about 5-7 days. For a 5-storey building the raft will not be very thick (say 600-900mm), but this depends on punching shear from the heaviest loaded columns. For a 30 storey building, the raft is very thick to increase the life of the building and to be able to withstand load.
