Need some advice on foundation for a rear double storey extension.
When you step out in to the garden you are on a platform that is approx 800mm above the ground level.
There are 3 steps down to the grass level and then the ground slopes down at a small gradient.
So if i lift the floor boards inside the house there is approx 3 feet drop to the ground and the joist are supported on brick posts.
For the foundations I am assuming that i would need to go down to 800mm to the garden level then a further 1 meter or when i hit solid ground. does this sound about right?
Would i be better of with piling or a foundation slab?