I'm considering buying a house where we would want to build on top of the garage, (or do a full double storey side extension if the garage isn't suitable to be built on). I've heard about the 45 degree rule for loss of light but I dont really understand it.
Here are two photos. the property we are interested in is on the right. Note that next door (to the left) has had a loft conversion and has a few windows on the side that would presumably be impacted by the side extension.
The garage seems to have been build right up to the boundary so the house doesn't have side access, so I expect we would want to demolish that external wall and introduce side access to mirror the access next door has.
Would you think there will be a problem with having planning approved because of next door's windows? The windows are on the north side of their property, so limited sun anyway, if that makes a difference.