Need help with Local Authority Planning?

Portland has years of experience in dealing with planning permission and local authorities, so you can rest assured that we will help you understand what is or is not required when obtaining planning for your conservatory.

You can of course contact us on 0800 294 9040 for further clarification.

You need to apply for planning permission to extend or add to your house in the following circumstances:

• You want to build an addition which would be nearer to any highway than the nearest part of the 'original house', unless there would be at least 20 metres between your house (as extended) and the highway. The term 'highway' here includes all roads, footpaths, bridleways, and byways if they are public rights of way.
• More than half the area of land around the 'original house' would be covered by additions or other buildings.
• The term 'original house' means the house as it was first built or as it stood on 1 July 1948 (if it was built before that date). Although you may not have built an extension to the house, a previous owner may have done so.
• You will also need to apply for planning permission if the extension or addition exceeds the following limits on height or volume.

Height limits for extensions

You will need to apply for planning permission before building an extension to your house if:

• The extension is higher than the highest part of the roof of the 'original house', or
• any part of the extension is more than 4m high and is within 2m of the boundary of your property.

You should measure the height of buildings from the ground level immediately next to it. If the ground is uneven, you should measure from the highest part of the surface, unless you are calculating volume.

Volume limits for extensions

You will need to apply for planning permission before building an extension if:

• For a terrace house (including an end of terrace house) or any house in a Conservation Area, a National Park, an Area of Outstanding Natural Beauty or the Broads Ð the volume of the 'original house' would be increased by more than 10% or 50 cubic metres (whichever is the greater).
• For any other kind of house outside those areas, the volume of the 'original house' would be increased by more than 15% or 70 cubic metres (whichever is the greater) and
• In any case, the volume of the 'original house' would be increased by more than 115 cubic metres.

Volume is calculated from the external dimensions of the entire structure of the extension.

In the following circumstances, the volume of other buildings which belong to your house (such as a garage or shed) will count against the volume allowances. In some cases, this can include buildings which were built at the same time as the house or existed on 1 July 1948.

• If an extension to your house comes within 5m of another building belonging to your house, the volume of that building counts against the allowance for additions and extensions.
• If you live in a Conservation Area, a National Park, an Area of Outstanding Natural Beauty or the Broads, and the building you wish to add would be more than 10 cubic metres in volume, it will (regardless of where situated in relation to the house) be treated as an extension of the house, and reduce the allowance for further extensions.
• Elsewhere, if you add to your property any building more than 10 cubic metres in volume and within 5 metres of your house, it will be treated as an extension of the house, and reduce the allowance for further extensions.

If any of these cases apply, the volume of the building concerned will be deducted from your volume limit for extensions and additions to your house. For example, if your volume limit is 50 cubic metres and a building of 15 cubic metres in volume is treated as an extension to the house, then your volume limit for extensions would be reduced to 35 cubic metres.

Please note - your local authority will confirm if your property retains 'permitted development' rights which allow you to build an extension without formal planning permission.

If formal planning permission is required, your local authority will also instruct on the application process.