Planning refused - overshadowing - appeal

[ranoutofquinoa]

Our house is a semi with a shared driveway. We wanted to build a wraparound double storey extension however, planning has been refused due to overshadowing.

The house was built virtually at. 45 degree angle to the house our extension will overshadow. The lovely neighbour seems ok with our plans, however planning have said that they need to think about future owners of the neighbours property,

Has anyone experienced bringing an issue like this to appeal? Or can suggest a planning consultant? We would be interested in changing our plans and we definitely want to stay put!

Sorry for the essay.

Double storey would always be tricky due to the overbearing nature of two storey walls.
We went out slightly further with the ground floor then the upper, partly because it broke up the large mass and partly to avoid being incongruous.
You probably need a more experienced architect with the planning system, ours passed first time with a really expensive architect but i know they send back anything if it isn't well designed, even non matching roofs at the back seem to be frowned upon