Question: Do I Need Planning Permission for a Conservatory extension?
Quick answer: It depends on the proposed size, location within the site and the area you live - but they are NOT exempt from planning permission.
Firstly, if your Permitted Development Rights (PD Rights) have been removed then you WILL need Planning Permission no matter what.
You can check your PD Rights by contacting the Local Authority Planning Department.
Then, for a semi-detached property, if the conservatory or extension is single storey and at the rear of the property then you can develop up to a 3m projection OR 3m-6m with extended PD Right until 30th May 2016.
If located at the side of the property then if may be up to half the width of the existing/as built/original building.
It make no real difference to the planning process or PD Rights if the development is a Conservatory OR an extension.
IMPORTANT: Please make sure that a least 75% of the roof area is glazed and a minimum of 50% of the wall area is glazed otherwise Building Control will require an application, foundation and structural details, possible heat-loss/thermal calculations and this will also attract a Building Control inspection fee.
Further info can be found on the Planning Portal - Conservatory Guide
OR check out the Planning Portal - Animated Guide it's great!
If you're unsure then please do not hesitate to get in touch - Thanks