Pricing guides

How much does it cost to build a conservatory extension?

The conservatory extension costs in this article are correct as of 2022

Adding a conservatory to your home is a great way to add more space, giving you a flexible room that can be used for dining, entertaining or relaxing, while enjoying plenty of natural light.

There are a number of different styles of conservatory, and a number of different available materials, all of which have an impact on the cost of a conservatory extension or garden room. We’ve outlined some of the common options and their costs.


Conservatory extension costs

There are a number of factors involved in constructing a conservatory that can affect the price, the most common of which are listed below.These will apply whether you hire a conservatory installer or an extension builder.


There are several different types of conservatory, split into common styles:

  • Lean-to conservatories have a single sloped roof attached to the original building.
  • Edwardian conservatories have a square or rectangular footprint, maximising the useful space, with a pitched roof.
  • Victorian conservatories have a rounded end, like a bay window, to give a wider view of the garden, as well as a pitched roof.

Lean-to styles are usually the simplest as they have only a single roof aspect. A basic lean-to conservatory (i.e one made of uPVC, with a polycarbonate roof and no dwarf wall) of around 4m x 3m will cost around £9,000 to £11,000 for installation.

An Edwardian conservatory with similar proportions and materials will cost roughly the same, around £10,000 to £12,000.

A similar sized Victorian conservatory with the same materials will typically cost around £11,000 to £14,000.

However, there are a number of other factors that can have a large impact on the price. Obviously, the overall size will have a big effect, but a number of other choices will have an impact. Some of those costs are listed below.

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Dwarf wall

A conservatory can either be constructed with floor to ceiling glass, or with a “dwarf wall”, usually consisting of several courses of bricks up to a metre high, which provides a solid base for the glazing and roof to sit on. The wall does add an extra cost to the construction process, but it adds stability and helps improve insulation, so is a popular choice. Generally, the extra work required will add around £1,000 to £2,000 to the overall price.



The roof of a conservatory can either be glazed, like the walls, be made of polycarbonate, a cheaper alternative, or be tiled like a traditional home roof. There are benefits and drawbacks to each. Having a glazed roof will let in the maximum amount of light, but some people find that it means a conservatory can become too bright or hot to use during sunny weather. A tile roof makes it easier to control the light, as well as adding better insulation, but will be more expensive. For a tiled roof, which may require the attention of a dedicated roofer, you can generally expect to add £600 to £800 per square metre to the overall build cost.


Conservatories can be constructed from uPVC, metal (typically aluminium), and timber. As with normal window frames, timber is the most expensive option, because the wood has to be high quality and correctly treated to ensure it lasts without weathering and rotting. uPVC is the cheapest, and should last for a long time, but many people can dislike the plastic finish.

Timber prices can range quite widely depending on the availability, quality and treatment of the wood, but generally, you can expect timber frames to cost at least 30% to 40% more than uPVC frames of the same size.

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