Conservatory Planning Permission Advice

In England and Wales you will not usually require planning permission, provided you do not exceed the permitted development limit for your property (which is 50-70 cubic metres, depending on where you live). Notable exceptions to the above are listed buildings and conservation areas. Please note that if your property has been extended in the past - you will have used up some or perhaps all of your "permitted development" area and may need permission. Its also worth noting that occasionally "permitted development" rights may be withdrawn from a property and any extension however small needs planning. If in doubt check.

Generally speaking conservatories/sunrooms on residential property are exempted under Building Regulations. Below are some of the Exemption Criteria - under the Building Regulations 1991 (as amended). These criteria must be met for a conservatory extension to be classified as exempt:

The extension walls are substantially glazed. Must have at least half the area of the walls formed of windows. Must have at least three quarters of the area of the roof formed of glazing, polycarbonate sheets or similar translucent material.

The extension has a floor area not exceeding 30m squared.

The extension is sited at ground level.

The extension is permanently separated from the remainder of the property by means of a door.

Any radiator within the conservatory is controllable. (If fixed heating installations are proposed, they should have their own separate temperature and on/off controls).

The glazing satisfies the requirements of part N, Schedule 1 (toughened/safety glass).

The extension does not contain any drainage facilities. (i.e. sink, WC, or washing machine)

For any other kind of house, the volume of the original house would be increased by more than 15% or 70 cubic metres (whichever is the greater).

Or in any case, the volume of the original house would be increased by more than 115 cubic metres. (The wording 'original house' means the house as it was first built or as it stood on 1st July 1948 if it was built before then. If extensions have been built since, then those extensions count against the allowance.)

The conservatory would be nearer to any highway than the nearest part of the original house, unless there is 20 metres or more between your house (including the conservatory) and the highway. (The term 'highway' includes roads, footpaths, bridleways and byways if there 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 conservatory is higher than the highest point of the roofline of the original house.

Any part of the conservatory comes within 2 metres of your boundary if it is more than 4 metres above the ground.

In the following cases, the volume of other buildings which belong to your house (such as 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 1st July 1948:

(i) If an extension to your house comes within 5 metres of another building belonging to your house, the volume of that building counts against the allowance for additions and extensions.
(ii) Any building which has been added to your property and which is more than 10 cubic metres in volume and which is within 5 metres of your house is treated as an extension of the house and reduces the allowance for further extensions.