Right, I have done a bit of investigating. A properly detached house 3 bed, 2 receptions, near by, went for £170k in 2009, needed updating, not as bad a state though.
A semi, 3 bed, 2 receptions, with new kitchen and bathroom, rest of it needed updating from the pictures, sold for £152,500 earlier this year.
From what I can make out from planning portal, anything attached would not be detached 4m rear extention under permitted development, so the link detached woule be the same as a semi so 3m permitted development rear extention.
So I have to allow for semi permitted development rules not detached, odd extention to next door and electrical substation. The substation is on the outside of the property, and lower down, as on a slope, there is currently my garage and an outbuilding (old outside wc and coal house thing) between the house I would like to buy, and some spare land the other side of the garage, currently uncared for, sloping down on the corner of the road going into another road, so the substation entrance is on the other road. I hope this all made sence?
I havent heard any more from the agent yet, I will chase tomorrow as don't want to appear too keen.
So provided I was happy and solicitor was with the boundary and party wall, and subject to survey, I think I will go ahead, I just have no clue still what to offer to make allowances for the offputting things to future buyers.