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Conservatory, orangery or extension?


Conservatory, orangery or extension?

The majority of us have been staying in more and working from home over the last six months, which has led to many homeowners reconsidering how they use their downstairs living space. If you’ve realised you need more room, here we look at three popular options to extend and what might be right for you.


A conservatory has traditionally been a quicker and less expensive way of adding more living space to a home. However, its popularity has waned in the last ten years with single storey extensions and orangeries finding favour. Conservatories can still be the right choice for some though, so what is the best option for you?

Estate agents suggest a conservatory can add up to 10% to the value of your home. The advantages of choosing to build a conservatory are that it is likely to be cheaper to construct than an extension of a similar size and its design is fairly flexible, enabling you to achieve an individual look and you may not need to apply for planning or building regulations.

If your conservatory is under 30m2 you don’t usually need planning permission though you should always check with your local planning department as there are exceptions for example if your home is listed or in a conservation area. 

Your conservatory is also usually exempt from building regulations too if it is:

•    Under 30m2
•    Thermally separated from the existing house by an external type door
•    It has a separate heating system 
•    At least 50% of a conservatory's walls and 75% of the roof must be glazed or translucent.

A conservatory is usually only used in the warmer months as heat loss from the room due to the amount of glazing in the windows and roof can make them too cold.  If you want to use your conservatory all year round, look at thermal insulation, electric panel heating or underfloor  heating and how you can limit the number of windows by perhaps having one solid wall. 

You will however, need to make a building regulations application if you alter the structural opening or create a new opening to access your conservatory.  Take a look at the section on conservatories in our Guide to Renovating your Home here for more in-depth information.


Conservatories and orangeries are often confused however, there are fundamental differences. An orangery is a more traditional looking structure and can be quite an impressive addition to your home. It should be a room you can use throughout the year, as whilst it still has up to 50% glazing in the form of large tall windows to let in the light, it will be set between brick piers which provide insulation. The roof will usually be of solid flat construction with a central lantern light which will also add to the thermal properties of the structure whilst still allowing light in. Orangeries don’t usually need planning permission but there are exceptions so always check with your local planning department.  They will however need building regulations approval and you can find out how to make an application on our website here.


An extension is likely to cost more than an equivalent sized conservatory, however being able to use your extension all year round for example as a playroom or office could mean the additional costs are outweighed. Most homes are suitable for an extension however, think about how you will access it, what effect it will have on your outside space, do you want it to match in with your existing home or make a statement?

Certain sized extensions also come under ‘permitted development' and may not need planning permission but you should always check with your local planning department as there are exceptions.  General guidance on whether you’ll need approval can be found on the Planning portal interactive house here.

An extension will however, always need building regulations approval as it a more complex project. We have written a chapter in our Guide to Extending your Home here on everything you need to know from what foundations and drainage are needed to heating and the types of roofs to choose from.


Building in an eco-friendly way can be a tricky balance but there are things you could consider including in your project to help save our environment.

  • Underfloor heating has less CO2 emissions and can be cheaper to run than traditional heating systems. Add thermostatic radiator valves and a room thermostat to an extension so you only heat the room you use.
  • Consider natural insulation materials such as hemp or sheep’s wool in wall and ceiling cavities.
  • Conservatories and orangeries have vast amounts of glazing and need to meet minimum U value standards for thermal performance, combined with floor and wall insulation this means less heat loss and lower energy bills as a result. (The cost of triple glazing may be prohibitive but would increase energy savings as well as blocking out noise.) Under the building regulations, all new and replacement windows must be rated as ‘C’ or higher or have a U value of 1.6 W/m2K or lower.
  • Consider installing photovoltaic panels (PVs) to the roof of an extension to produce electricity from the sun to run your home. A PV solar system on a typical home can save one tonne of polluting carbon emissions a year.
  • Try to use local trades and supplies to reduce your carbon footprint.  If you are considering a timber framed conservatory think about using European Oak or use of reclaimed bricks and floor boards for an orangery.

How building control can support you

If your project needs a building regulations application, building control will be with you every step of the way once you have submitted your application and paid the valid fee. Your project will then be assigned to one of our professionally qualified surveyors.  They will check any plans and our inhouse structural engineers will check any structural calculations before your builder arrives. We will also send you all the information you need to help you understand the steps in the building control process. 

When work does start you or you builder then contact us to book a site inspection. As well as checking progress and that work meets the building regulations we will explain when we next need to visit and provide any support or answer any questions you or your builder may have.  Once work is complete and we have carried out a satisfactory final inspection (and any relevant competent person records have been submitted electronically to us – find our more here) we will issue you with a completion certificate which you should keep in a safe place for future refence. (It will be needed if you sell or mortgage your home.)

If we inspired you to extend your home and you’d like to discuss your project with us please get in touch by calling 0330 0249355 or email