hi.
the wall around the pool area is built as such to deal with the gradient of the land on which it sits,as are the houses(stepped)the wall is one brick high at furthest end gaining height as ground level lowers,pool will be built level inside this area.(i hope anyway or there wont be much water in the pool to swim in.)
you get a better idea if you see it in the flesh so to speak.(the artists impression is on flat ground)
cheers
billy