Do I need planning permission for a conservatory in Cornwall?

So, you’re thinking about getting a conservatory? Wonderful idea! If you’re not in the market for a full extension, conservatories are a cost-effective way to extend your home. Not only do they give you a whole extra room in your house (for you to use however you please), but they’re also designed to bring in lots of light and act as a bridge between your interior and the outdoors.

Do I need planning permission for a conservatory in Cornwall?

While it can be tempting to get swept away thinking about how you’re going to style your new space, there are some practical points to consider. The most important of which is…. Planning permission.

Don’t worry, it sounds scarier than it is! And to make things a little easier, we’ll be discussing everything you need to know about getting planning permission for your conservatory in this article.

Ready? Let’s get started…


Building regulations for conservatories

We’ll start with the good news. Most new conservatories don’t actually require any planning permission. That’s right! Generally speaking, they’re allowed as ‘permitted development’ — thanks UK Gov!

This being said, your new structure will still need to meet some basic requirements.

Your conservatory must not:

  • Cover more than half the area of your original house.
  • Be more than four metres high, extend more than four metres from a detached property, or three metres from any other house (with a few exceptions).
  • Be built to exceed the highest part of your existing roof.
  • Exceed three metres in height at the eaves if it is within two metres of a boundary.
  • Be built forward of the ‘principal elevation. If it fronts a highway it cannot be built forward of the ‘side elevation’.

It also can’t include:

  • A microwave antenna such as a TV aerial.
  • A Chimney, soil or vent pipe, or flue.
  • An alteration to your existing home’s roof.
  • Verandas, balconies or other raised platforms.

More rules apply specifically to side extensions, single-storey extensions, and multi-storey extensions that you can find through the Planning Portal (along with further details about the above requirements).


How big can my conservatory be?

Your new conservatory must be less than 30 square metres in floor area to be exempt from building regulations. Any bigger than this and you’ll need approval. It must also be separated from the house by external quality walls, doors or windows.

If your single-storey structure will extend past the rear wall of your original property by over four and up to eight metres for detached houses and over three and up to six metres for other houses, then you’ll need something called ‘Prior Approval’.


How much glass does a conservatory need?

It might seem slightly picky, but there are minimum glass coverage requirements that your conservatory must meet. 

Ensure that at least 50% of your structure’s walls and 75% of the roof is either glazed or translucent. If you want to dip below these ratios, that’s right — you’ll need planning permission!

P.S. If this seems a little daunting to figure out on your own — don’t fear. An experienced provider will know these regulations inside and out. They’ll ensure your structure complies with the legal limits!


Does a conservatory need foundations?

Your conservatory must have structural integrity, and foundations help to ensure this. So, yes — you should build your conservatory with foundations.

There is no specific depth that your foundations must be, so this will be based on the weight of your new structure and the type of ground it will rest on — things any reputable conservatory provider will be able to determine.

Your provider will also be able to see what kind of foundation you require. Most of the time a strip foundation will do the job, but a pile foundation might be needed where the ground is a little unstable. 

You can ask your installer about the difference, but it’s up to them to make sure your conservatory is built to safe standards — not you!


Are there regulations for conservatory glazing?

Your conservatory glazing must meet the same standards that the glazing in the rest of your house complies with. This means that there will be efficiency and safety requirements for your glass.

Your provider will be able to explain what this means for you and talk you through your options. At CTG Windows, we even offer speciality glazing, such as UV resistant glass, Stadip Silence laminate and self-cleaning glass.


Do I need planning permission to get a radiator in my conservatory?

To put it simply — no.

You don’t need to get planning permission to install a radiator in your conservatory as long as it is an isolated mains radiator (one which can be controlled separately from your central heating).

This is important to note, as if you install an integrated central heating system in your conservatory it will have to comply with heat loss regulations.

Keep in mind that there are other ways to heat your conservatory using an isolated heating system. You can use electric heaters and install underfloor heating without getting planning permission, so consider your different options.

The key thing to remember is that conservatories require an independent heating system with separate on/off controls to be exempt from building regulations. So stick to this and all will be fine!


Does a conservatory need external doors?

Yes, it does!

Your conservatory must have two sets of doors; those that connect to your house via external doors and also those that open to your outside space. Doors that open wide and allow easy access, such as French doors, are preferable. They’ll let the light from the conservatory reach other ground floor rooms and help to integrate your structure with the rest of the house.

Keep in mind that Planning Portal guidelines stipulate that you’ll need building regulations approval to create a new structural opening between your conservatory and your house, even if your conservatory itself doesn’t require permission.


CTG Windows

It might seem like there are lots of rules for your new conservatory, but in reality, most conservatory plans easily meet these requirements. At CTG Windows, we’ve helped countless homeowners achieve their conservatory dreams with minimal planning hassle. 

Give us a call to learn more about our bespoke conservatories or drop by our Hayle showroom to see some examples. To see some past case studies right now, view our online brochure.

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