What are the building regulations on ground level height and boundary lines when building a housing estate?

The housing estate is planning to be built next to another housing estate. the ground level will differ in height between the two housing estates, and the boundary lines between the two housing estates will be as little as possible, depending what the laws and regulations allow. this building site is in warwickshire and on land that was previously owned by the local council before it was sold to barratt homes.
Answer
The only people who can answer this question are the local council. building regs. can vary between different authorities.