Planning Permission

A guide to planning requirements for building a DIY conservatory.

With modern families constantly looking at ways to improve, upgrade and add space to their homes planning requirements are getting tighter to ensure that the building work is in keeping with neighbouring properties and local area.

Under present local authority legislation you may not need planning permission providing you meet with the following points.

A Detached Property
Without planning permission you can develop up to 70m3 or 115% of the total volume of the property, whichever is the greatest? However, this is a combination of the total amount of extensions, e.g. if you had a lounge extension of 35m3 and a conservatory of 46m3 this would total 81m3 and you would then require planning permission. If your total is less than 70m3, or 115% of the volume of the existing building, planning permission would not be required.

A Semi-Detached Property
A semi-detached property has the same rules as a detached property, you are allowed to develop up to 70m3

Terraced and End Terraced Properties
The same rules apply to these as detached and semi detached properties. But the amount you are allowed to develop is reduced to 50m3.

Flats and Maisonettes
You are not permitted to develop these properties with obtaining planning permission, there are no exceptions to this rule.

The above mentioned apply to developments carried out after July 1, 1948.

There are some additional points and conditions which can alter whether or not you will require planning permission and are as detailed below:-

If your conservatory covers an area greater that 50% of the original garden.
If your planning development rights have been removed
If you build your development within 2m of the boundary line and the highest point at that junction is 4m or higher
If you property is a Grade II listed building. These may require hardwood conservatories with glass roofs. Rules can be very strict with these properties.
If your conservatory or development is 20m or less from a road or public footpath

Boundary Impact
A planning officer will be looking at the projection of the conservatory (how far it will protrude into the garden) normally they will be satisfied with an approximate 3m projection from the original property. Should you proposed development or conservatory protrude more than 3m he may not look at it so favourably and may ask for the size to be reduced. This is so that neighbours and neighbouring properties do not have to look at large brick walls more than 3m long.

If planning permission is not required a letter of lawful development from your local authority is something you are able to obtain. In the event of selling your property it will show you have complied.

If you are in any doubt always ask you local planning office. They will be more than happy to help and give guidance so that costly mistakes are not made.