The building regulations that apply to most conservatory projects are minimal. As long as the conservatory meets a handful of simple requirements, you won’t need to worry about the majority of rules that apply to extensions.

While the regulations for a conservatory may be simple, KLG Rutland has put together these FAQs to make sure that you have access to the most important information. If you’re still unsure after reading these, give us a ring to talk to us directly.

Do I need planning permission for a conservatory?

Most conservatory installations will not require planning permission. This is because adding a conservatory to your home is usually allowed under the ‘permitted development’ rules. However, if a planned conservatory falls outside of some basic requirements it will require planning permission.

Some of the most important requirements to bear in mind if you want to avoid planning permission are:

  • No more than half of the area of the “original house” can be covered by extensions.
  • The conservatory must be no more than 4 metres high and cannot extend more than 4 metres from a detached house, or 3 metres from any other house (in most cases).
  • It cannot be higher at any point than the highest part of the existing roof.

See Planning Portal for a full list of requirements to avoid the necessity for planning permission.

What percentage glass does there need to be in a conservatory?

At least 50% of a conservatory’s walls and 75% of the roof must be glazed or translucent. These requirements are in place to prevent the need for further building regulations. If you keep to those minimum requirements, more extensive regulations will not apply.

Does a conservatory need foundations?

Conservatories need foundations to ensure their structural integrity. However, there are no building regulations specifying the depth that the foundations must be. In practice, the foundations’ depth will be determined by the weight of the conservatory and the type of ground upon which it sits.

Along with different depth requirements, there are many types of foundations that may be used to support a conservatory.

Most conservatories would require a strip foundation build. However, in certain cases where there is unstable ground, trees or heavy clay, a raft foundation or even pile foundation may be required.

It is important that whoever is installing your conservatory has taken proper measures to make sure that the foundation is safely planned. Don’t be afraid to ask your installer about the foundations if you’re curious or unsure.

Does a conservatory need external doors?

Yes, a new conservatory must be connected to your house via external doors and windows. This means that you need to consider doors like french doors or sliding doors to allow access from the original house to the conservatory.

We typically recommend that homeowners choose doors that allow wide, easy access to the new conservatory. This allows it to feel like an integral part of the house and brings the light from the conservatory into your other rooms.

Are there any regulations for a conservatory’s glazing?

A conservatory’s glazing is one aspect that does come under full building regulations, along with permanent electrical installations. All glazing in a conservatory must meet the standards required for any glazing in the rest of the house, adhering to the requirements for both U-value (efficiency) and safety.

Any good conservatory installer should be able to meet the minimum requirements and some may be able to provide glazing that is more efficient and safer than standard. Make sure you ask questions before committing to a particular installer if you have any concerns.

Do I need planning permission for a conservatory with a radiator?

You do not need planning permission to put a radiator in a conservatory. Isolated mains radiators that can be controlled separately from your central heating do not require planning permission and are exempt from heat loss regulations. If you install an integrated central heating system in your conservatory, it will need to meet the building regulations on heating efficiency.

How should I heat my conservatory?

You have several options when it comes to heating your conservatory, but some are more complex than others. The most important thing to bear in mind is that a conservatory is only exempt from regular heat loss regulations if its heating system is isolated from the rest of the house and can be controlled separately.

We have listed the four most common choices in order of difficulty, from the easiest and quickest to the hardest and most time consuming. That’s not to say that one is better than the others, but it’s important to get a sense of the work required.

  • Electric heaters. Heaters that plug into the mains and switch on and off on their own are the simplest option. Simply acquire one and plug it in. However, these heaters are not known for their efficiency.
  • Underfloor Heating. Most people like a casual floor finish such as ceramic, wood or laminate, meaning that there are a range of underfloor heating systems that can provide adequate heating whilst complying with the isolation rules.
  • Isolated mains radiator. It is possible to extend your heating system into the conservatory and isolate the radiators so that they meet the above requirements. This is time-consuming and needs to be done carefully, but will keep the conservatory free of building regulations.
  • Fully integrated central heating. There’s no reason why you can’t extend your central heating into your conservatory as you would in any other room. Just remember that doing so will mean you have to meet a more extensive range of heat loss regulations.


Here’s a quick recap of the different pieces of information we’ve given you in these FAQs to help your conservatory stay on the right side of building regulations:

  • The proposed conservatory should be under 4 metres tall and extend less than 4 metres from the original house for detached houses and 3 for other houses, otherwise you’ll need planning permission.
  • 50% of the walls and 75% of the roof need to be glazed or translucent. If it isn’t, building regulations will apply.
  • The glazing must meet standard U-value and safety requirements that apply to all glass in a home.
  • Your conservatory needs a foundation.
  • A conservatory needs to be connected to the original house by external doors and windows.
  • A conservatory’s heating system must be isolated, otherwise it will be subject to the same heat loss regulations as the rest of the house.

Remember if you work outside these basic rules then your construction will require building regulations. This will bring in further rules and additional costs.

Visit our conservatories page to see KLG Rutland’s full range. We’re experts in conservatory manufacture and installation, installing bespoke designs around Nottinghamshire and Derbyshire. Alternatively, contact us directly to get a quote or ask a question.