Meeting the planning department
Whenever you think about the possibility of building an extension to your house you should always go and see your local council planning department as the first step.
Do I need to make a planning application?
I'm not sure how all planning departments operate but they will usually ask you to complete an informal form to determine whether you actually need to apply for planning permission (2018: this used to be free but you will p[robably have to pay for this now).
Even if you believe you do not have a need to obtain planning permission because of the scale of your development, gaining the written approval of that you do not need permission could be very beneficial later on, if you find local residents complaining for whatever reason during the build phase.
A more important reason is to ensure that you provide sufficient information so that they can make the determination quickly without having to resort to coming back to you for further information. The last thing you want is delay!
Moreover, in my experience planning departments are generally very helpful and are very willing to spend a little time sitting down with you and answering all the questions you may have and providing advice on how to proceed.
With my particular extension which is quite small, I did not feel that I needed planning permission so I visited the local planning department and asked to talk to a planning officer about what I wanted to do. They will usually ask for your address at reception and will the planning officer will come out to talk with you armed with the planning request history of your property if there is any.
The volume of the extension.
The guidance from my local council is shown above . These volumes are measured up to the eves of the extension and house and should not not include the roof space. Also, extension volumes are cumulative, so if you have had previous extensions then you need to add those to the volume of your new proposal.
The volume of my extension was approximately 18 cubic metres and I had previously extended my garage by 7 cubic metres making a total of 25 cubic metres. The volume of my house - calculated after taking measurements - turned out to be around 500 cubic metres. 15% of which is 75 cubic metres, so my extension falls well within the limits of not needing planning permission. This was my assumption prior to my informal talks with the planning department.
The meeting
On a pleasant day in February, armed with my sketches and photos, I made my may to my local planning office to check whether there would be any issues with my plans to build a small extension at the rear of my house.
The meeting went well. We discussed my sketches and the relation of the extension to the boundaries as any extension that is less than 5 metres from a neighbour's boundary needs planning permission I think. The only point that was raised, was that I needed to include my shed in the sketches that would be submitted with the form above as it had a volume of greater 10 cubic metres and was less that 5 metres away from the proposed extension.
I also needed to show in the sketches my previous garage extension.
Other than this, he felt that there would be no other issues and that planning permission would not be required. So, all in all, quite a satisfactory meeting.
All I needed to do was to add a few details to my sketches, complete the form above and the they would come back to me within ten days as to whether permission was needed or not.
Quite a pleasant and useful experience really! This is so easy to do - why would you not do it? But, this is often the case for some reason.
Next step
19th February: The next step is to formally complete and submit the above form together with my sketches to the council to ensure I have their agreement about not needing planning permission. Fingers crossed!
11the March: I today received a letter from the council saying that I did not need to apply for planning permission, so I can the build when I'm ready to do so.