Do You Need Planning Permission for a Conservatory?

What permitted development means

Permitted development rights let you carry out some types of building work on a house without making a full planning application. For planning purposes, a conservatory is treated as a single-storey extension, so it follows the same rules.

The limits are measured against the original house. That means the house as it was first built, or as it stood on 1 July 1948 if it is older. Any extensions added since then count towards your allowance, even if a previous owner built them.

The main limits in England

These are the headline rules from the Planning Portal for a conservatory to count as permitted development in England:

• It must not be built forward of the principal elevation, which is usually the front of the house, or forward of a side elevation that faces a road.
• A single-storey rear conservatory can go up to 3 metres from the back wall of an attached house, or 4 metres on a detached house.
• It must be no more than 4 metres high.
• The eaves must be no higher than the eaves of the house, and the highest part no higher than the roof ridge.
• If it is within 2 metres of a boundary, the eaves must be no higher than 3 metres.
• A side conservatory must be single storey, no more than 4 metres high and no wider than half the width of the original house.
• Together with other extensions and outbuildings, it must not cover more than half the land around the original house.

There is also a prior approval route in England for larger single-storey rear extensions, up to 6 metres on an attached house and 8 metres on a detached one. You have to notify the council first, and they consult your neighbours before deciding.

When you will need to apply

Even a modest conservatory may need planning permission in these situations:

• You live in a flat or maisonette. Permitted development rights for extensions apply to houses only.
• Your home is on designated land, such as a conservation area, a National Landscape (formerly an Area of Outstanding Natural Beauty), a national park or a World Heritage Site. Side conservatories are not permitted development there.
• Your home is listed. You will need listed building consent for most changes, whatever their size.
• Permitted development rights have been removed, either by a condition on an earlier planning permission or by an Article 4 direction. This sometimes applies on newer estates.

If you live in Wales

My working area crosses the border. Wrexham, Chirk, Llangollen and Welshpool are all in Wales, where permitted development rules are set by the Welsh Government. The idea is the same, with limits on height, depth, distance from boundaries and how much of the garden you cover, but some of the details differ from England.

If you are in Wales, read the Welsh Government guidance on conservatories at gov.wales or ask your council. That will be Wrexham County Borough Council, Powys County Council or Denbighshire County Council, depending on where you live.

Building regulations are a separate question

A conservatory that does not need planning permission may still need building regulations approval, and the other way round. According to the Planning Portal, a conservatory is normally exempt from building regulations if:

• It is built at ground level, is single storey and has a floor area under 30 square metres.
• It is separated from the house by external quality walls, doors or windows.
• It has its own heating system with separate temperature and on/off controls.
• The glazing and any fixed electrical work meet the relevant regulations.

If you take out the wall or doors between the house and the conservatory, that new opening needs building regulations approval, even if the conservatory itself is exempt. Swapping a glazed roof for a solid one can also change things, which we cover in a separate post on solid conservatory roofs.

How to check before you commit

• Check your council's website to see whether your home is listed or in a conservation area.
• Look through your deeds and any past planning permissions for conditions that remove permitted development rights.
• Use the Planning Portal interactive guide in England, or the gov.wales guidance in Wales.
• If you want certainty, apply to the council for a lawful development certificate. It confirms the work does not need planning permission and can help when you come to sell.
• Talk to your neighbours early, especially if the conservatory will be close to the boundary.

A planning assessment is part of every Shelfbank conservatory survey. I will look at where the conservatory would go and flag anything that might need permission, but the council always has the final say.