Meeting the Council Planners
Armed with my Cad drawings and a series of Sketchup pictures, I went to chat with my neighbours to see if, in principle, they had any objections. They were all impressed by the Sketchup pictures as they could see exactly how my extension would look rather than having to decipher 2D layouts (maybe wrongly). They were all very happy with my proposal, none of them feeling it would have any effect on them. Both as a courtesy and maybe to foresee any potential problems, I strongly recommend you consult neighbours personally before making a submission.
I optimistically wandered into the Council Planning Department confident that they too would be happy with my proposal - WRONG!
The Conservation Team were unhappy with the single storey section rising to two, claiming it would block light and view.
Honestly, I felt neither point was valid, and politely pushed the planner for advice on how I might maintain my design yet tweak it to appease the Conservation Team. She advised me to lower the roof line. I didn't realise, but planners are very keen that any extension should appear just that - an obvious addition to a dwelling, not a seamless continuation where it's indistinguishable from the original (as I had proposed, naively). She also advised that I make a step in the brickwork so that the line of the wall is broken. I live in a Conservation Area and own a period property, so it may be that my Local Council are particularly keen on such details.
I realised that I had not really done my homework on such matters. There are conservation area restrictions to consider over and above planning issues for anyone living in a designated conservation area. Obviously, had I employed a local architect they would be well versed in such matters could have offered conservation area guidance and would not have made the same mistake. However, I did find the planning team were happy to chat to me. In retrospect I should have considered developmentin conservation area and chatted to the planners at an earlier stage, before I had spent so much time. Understanding preferences held by local planners will go a long way to ensuring you design something that is likely to be accepted.
Still, I had not officially made a submission, so I had the opportunity to make some changes before doing so.
Back to the Internet and I found some really useful Planning advice from www.planning-applications.co.uk. Ian, the guy behind the site, has put together some great information on all aspects of planning, and was even kind enough to reply to a couple of e-mail queries. I revisited my Local Council website and found more information (you really should trawl the Council site - my Council has lots of information). I even found that the advice on roof lines etc. was posted in one of the Council's guidance documents. I strongly advise you do all the homework you can on such matters, and chat directly with the Planning Department. At the end of the day, they get to say yes or no to your proposal.
I tweaked my drawings and felt I could lower the roofline and step in the brick course, yet maintain my present design. I wasn't totally happy with the compromise, but did so to accommodate the planners sensibilities.
I redrew and set about making my application.