September 15, 2020

How Big Can A Conservatory Be Without Planning Permission?

Conservatory Planning permission – do you need it or not?

The good news is that nowadays you can build a new conservatory twice as big as you used to be able to post May 2019. This means that for a semi-detached house you could extend by as much as 6.0 Metres.

However, it’s quite understandable to have some doubt or uncertainty when it comes to planning permission for conservatories. However, of late, the guidelines / rules have become a lot easier to understand.

Here we look at the main elements that you need to have in mind before building a new conservatory.

What is Planning Permission for a conservatory?

According to the UK Planning portal, it is:

“in simple terms, it’s asking if you can do a certain piece of building work. It will be granted (possibly subject to certain conditions) or refused.”

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The primary responsibilities for granting, or refusing, permission is in the hands of your local authority (council).
The responsibility for getting, or not getting, planning permission is in your hands.

If you proceed without it when it was originally needed, then you have committed a Planning Breach.

Committing a planning breach is not always necessarily an illegal act. In some cases your local council will allow a retrospective application to sort things out.

But they can also issue an enforcement notice demanding you “undo” what you have done. You cannot refuse to comply with an enforcement order without being prosecuted unless the enforcement order overturned by a legal appeal.

Making a mistake with planning can be both costly and time consuming.

However, many conservatories fall within “permitted development rights” and can be built without needing to apply for permission.

How big can a conservatory be without planning permission?

As we mentioned above, subject to certain conditions, your new conservatory may not need planning approval prior to construction.

In 2019 the UK government relaxed some of the conditions surrounding permitted development rights to the following extent:

In a nutshell:

Terraced properties can extend by up to 6.0 Metres
Semi-detached homes can extend by up to 6.0 Metres
Detached houses can extend by up to 8.0 Metres

Single storey conservatories may also be built without permission if:

It is a maximum height of 4.0 Metres (3.0 Metres high within 2.0 Metres of a boundary line).
Your new conservatory does not take up more than 50% of the garden.
The roof top of the conservatory is not higher than your existing property roof eaves.
As a side extension, it won’t make the whole property more than 50% wider.

If you are thinking of putting a conservatory on the front of your home, then that’s a bit more complicated. Front facing conservatories are not normally allowed unless your property is a “considerable distance” from the main road. That distance was set at a minimum of 20 Metres prior to 2008.

You are well advised to consult your local authority about this option beforehand.

For conservatories at the larger end of the scale, you could still have to consider any potential negative impact on your neighbours’ lifestyle and go through Neighbour Consultation Scheme (NCS).

The guidelines for larger home extensions that may require you to go through the Neighbour Consultation Scheme are:

If you are going to build a conservatory that will extend beyond the rear wall of the original house by:

Over 4.0 and up to 8.0 Metres for detached properties
Over 3.0 and up to 6.0 Metres for semi-detached & properties

See the UK Planning portal here: https://www.planningportal.co.uk/info/200130/common_projects/17/extensions/2

Points to bear in mind

There are still some circumstances that, even if your conservatory fits the guidelines, where prior approval is essential, such as:

If your property is situated in a place of special scientific interest
If your property is situated in conservation area, National Park
If your property is situated in a World Heritage Site or Area of Outstanding National Beauty (AONB)
If your property is a flat or maisonette.
Scotland, Wales, and Northern Ireland have different planning rules.
If you have already “used up” your permitted development rights.
If there are any restrictive covenants on the property.

The changes to permitted development rights from 2019 do not apply in these circumstances.

Building regulations

Just because your conservatory does not need planning permission does not mean that you do not need to comply with local building regulations unless:

The floor area is 30 square metres or less, provided that in the case of a conservatory or porch which is wholly or partly glazed.
Any heating system is independent of your main home central heating with its own on/off switch.
It’s only built at ground level.
There are external quality windows / doors separating the main house and the conservatory.

As an example, if you are going for an open plan conservatory, such as extending your living room – then this falls foul of rule #4.

If you run extra radiators into the conservatory from your current boiler, then this falls foul of rule #2.

Do I need to get permission for a solid conservatory roof?

This question is a tricky one, because there are quite a few considerations to be taken into account.

For example: If you already have a tiled or solid conservatory roof and are just doing a “like-for like” renovation, then it’s unlikely that you need to apply for new permission.

If, however, you are changing from glazed / translucent to solid then, not only do you have to comply with building regulations, you may be changing the designation of the conservatory from “temporary” to “permanent”.

That proposed change could mean you fall out of the permitted development category and end up needing planning permission to do the work.

Ensure you discuss this in detail with your contractor. Luckily most experienced and reputable conservatory roof installers will be well aware of the regulations. They will be able to help deal with all the “red-tape” involved as part of the installation.

For more information about prices, see our article about the cost of replacing a conservatory roof.

Conservatory Planning Permission Summary

We trust that our guide has given you a better idea of how big your conservatory can be without planning permission and that you have a greater understanding of the factors involved.

However, this article is just a guide and things can change over time.

Our advice is to firstly, discuss this in detail with your proposed contractor / installer and establish if they are going to be responsible for this area.

Secondly, we would advise to also get in touch with your local authority to do your own due diligence.

You can find your local authority here: https://www.gov.uk/find-local-council

Here are some useful links:

If you want to know how much a new conservatory for your home costs, then we can arrange free quotes Nationwide from trusted & accredited conservatory installers.