Our houses are about 12 years old now, we've lived in ours for about 8. I didn't realise how thin the top soil was until I was doing some work in the garden a few years ago.You guys are getting topsoil? Maybe 3-4 inches before it’s all clay by me.
I spoke to our next door neighbour, who has lived in his since it was built, and he said all the houses around our way are in the same boat regarding the measly layer of top soil.
Apparently the building company who got the contract to build them tried saving money left right and centre, and saving money on top soil was one of the areas! Not a problem unless you are a keen gardener, then it can cause you issues with drainage etc.