Conservatory Extension Cost Guide for the UK

Quick Cost Overview

• Most conservatory extensions cost between £9,000 and £40,000 fully installed.
• A lean-to conservatory is the most affordable, starting from around £8,000.
• Most conservatories fall under permitted development and do not need planning permission.
• A well-built conservatory can add 5 to 10% to your home's value.

Conservatory Extension Cost Guide: Contents

1. Conservatory Extension Average UK Costs
2. Conservatory Extension Costs by Type
3. Material Choices and Their Impact on Conservatory Costs
4. What Affects the Cost of a Conservatory Extension?
5. Planning Permission for Conservatory Extensions
6. Conservatory Extension vs Extension Costs
7. Tips to Save Money on Your Conservatory Extension
8. Find a Conservatory Installer on MyBuilder
9. FAQs: Common Questions About Conservatory Extension Costs

Conservatory Extension Average UK Costs

The average cost of a conservatory extension in the UK sits at around £15,000 to £20,000 for a mid-range, fully installed build.

However, the range is wide - a simple lean-to conservatory in uPVC can be completed for £8,000 to £15,000, while a bespoke P-shaped or timber conservatory with a solid tiled roof can easily exceed £40,000.

The table below gives a useful starting point based on typical installed costs:

Conservatory Style	Typical Installed Cost
Lean-to (uPVC)	£8,000 - £15,000
Edwardian (uPVC)	£9,000 - £17,000
Victorian (uPVC)	£10,000 - £18,000
Gable-end	£12,000 - £20,000
P-shaped	£15,000 - £25,000
Orangery	£16,000 - £35,000
Bespoke timber or aluminium	£25,000 - £40,000+

These figures assume a standard installation with a glass or polycarbonate roof. Upgrading to a solid tiled roof adds significantly to the cost, typically £5,000 to £15,000 more depending on the size and spec.

For comparison, a garden room offers a fully insulated alternative that tends to cost more upfront but performs better year-round without additional heating.

A mansard loft conversion is another option worth considering if vertical space is available.

Conservatory Extension Costs by Type

The style you choose shapes everything: the look, the light, the floor space, and the price. Some styles suit certain properties better than others, and it is worth thinking about what the conservatory will feel like from the inside as much as how it looks from the garden.

Here is a breakdown of the most common options, what each one delivers, and what to expect to pay.

Lean-To Conservatory

The most affordable and straightforward option. A lean-to has a simple sloped roof that attaches directly to the house wall, requiring fewer materials and less labour than other styles. Ideal for bungalows, smaller plots, or properties with limited space. Installed costs typically range from £8,000 to £15,000 depending on size and materials.

Edwardian Conservatory

A square or rectangular design that maximises usable floor space. Edwardian conservatories are more practical than Victorian styles for everyday use and are generally better value - their simple shape uses materials more efficiently. Typical installed costs range from £9,000 to £17,000.

Victorian Conservatory

Characterised by a bay front with angled or curved sections and decorative detailing - well suited to period properties. The curved design requires more materials and specialist installation, pushing costs higher than Edwardian equivalents. Expect to pay £10,000 to £18,000 for a standard uPVC build.

P-Shaped Conservatory

A combination of two styles, typically a lean-to and a Victorian or Edwardian, joined together to create a larger L or P-shaped footprint. More material and structural complexity makes these one of the pricier options, typically £15,000 to £25,000.

Orangery

An orangery sits between a conservatory and a full extension, it typically has more solid brickwork, a flat ceiling with lantern lights, and a more substantial roof structure. More architecturally considered than a standard conservatory, and more expensive accordingly. Costs typically range from £16,000 to £35,000 depending on size and spec.

For design inspiration, see our conservatory extension ideas article.

Material Choices and Their Impact on Conservatory Costs

Frame material is one of the biggest variables in the final cost of a conservatory extension. Here is how the main options compare:

uPVC

The most popular and affordable choice. uPVC frames are low-maintenance, well-insulated, and available in a wide range of colours including wood-effect finishes. Modern reinforced uPVC can achieve an A+ energy rating. A standard uPVC conservatory costs from around £10,000 to £15,000 for a basic build.

Aluminium

Slimmer frames than uPVC, allowing larger glazed areas and a more contemporary look. Aluminium is highly durable, requires virtually no maintenance, and can be powder-coated in almost any colour. It typically costs around 25% more than uPVC for the same specification.

Timber

The premium option, offering a natural, traditional aesthetic that suits period properties particularly well. Hardwood timber frames require regular painting or treating to prevent weathering, which adds to the long-term cost of ownership. Timber frames typically cost around 50% more than uPVC and bespoke timber conservatories can start from £25,000 for a modest build.

Roof options also significantly affect the price:

• Polycarbonate: The most affordable roofing option but the least effective for insulation. Tends to be hot in summer and cold in winter.
• Glass: Better insulation than polycarbonate; self-cleaning and solar-control glass options available at a premium.
• Solid or tiled roof: The best-performing option for year-round use. Adds £5,000 to £15,000 to the overall cost but transforms the space into a room usable in all seasons.

For energy-efficient upgrades and ways to reduce running costs, our green energy solutions article covers relevant options including underfloor heating and insulation.

What Affects the Cost of a Conservatory Extension?

Beyond style and materials, several other variables shape the final price of your conservatory extension:

• Size: The most straightforward cost driver - every additional square metre adds approximately £300 to £600 to the overall cost depending on style and complexity. A 3m x 3m build is significantly cheaper than a 5m x 4m equivalent.
• Glazing specification: Standard double-glazed units are included in most quotes, but upgrading to triple glazing, solar-control glass, or self-cleaning glass increases costs. Triple glazing can add £1,000 to £2,500 to a standard build.
• Foundations and groundwork: The ground conditions on your plot affect the depth and complexity of the foundations required. Sloping ground, poor soil, or sites with drainage issues all add cost. Foundations typically add £1,000 to £3,000 to a standard project.
• Dwarf wall vs. full glazing: A dwarf wall (a low brick wall beneath the glazing) helps moderate temperature and reduces cleaning requirements. Full-height glazing is more popular for contemporary designs but provides less thermal buffering.
• Location: Labour rates in London and the South East typically run 20 to 30% higher than national averages.
• Time of year: Booking in winter or early spring, when demand for conservatory installers is lower, can sometimes reduce costs or shorten lead times.

Planning Permission for Conservatory Extensions

Most conservatory extensions in the UK fall under permitted development rights and do not require planning permission, which is one of the practical advantages conservatories have over full extensions.

Permitted development rules allow homeowners to make certain improvements without going through the full planning process, provided the work stays within defined limits on size, height, and position.

• The conservatory does not exceed 50% of the total area of land around the original house
• The conservatory is no higher than 4m (or 3m if within 2m of a boundary)
• It does not extend beyond the principal elevation (front wall) of the house
• It is separated from the main house by external-quality walls, doors, or windows

If your property is a listed building, in a conservation area, or in an area of outstanding natural beautyadditional restrictions apply and permitted development rights may not apply at all.

Building regulations do not typically apply to conservatories that meet the permitted development criteria, but if you are adding a solid roof, heating, or electrics, building regulations approval may be required. For full detail on costs and requirements, see our planning permission cost guide.

Always check with your local planning authority before work begins - the rules can vary depending on your specific property and location.

Conservatory Extension vs Extension Costs

For many homeowners, a conservatory extension and a single-storey rear extension are both on the table, and the right choice depends on how you plan to use the space, your budget, and how much disruption you are willing to take on.

Cost

A conservatory is almost always cheaper than a full extension for the same footprint. A standard single-storey rear extension typically costs £30,000 to £50,000 for a 20m² build, while a conservatory of the same size can be completed for £15,000 to £25,000.

The saving comes primarily from the structure itself - a conservatory uses a lightweight glazed frame rather than brickwork, foundations, and a plastered roof.

Year-Round Usability

This is where the gap between the two options narrows. A traditional polycarbonate-roofed conservatory can be uncomfortably hot in summer and cold in winter, which limits how much it is actually used.

A solid or tiled roof conservatory, or an orangery, closes much of that gap and performs similarly to a full extension, but at a cost premium that can bring the two options closer in price.

Property Value

Both add value, but a full extension tends to add more. A well-built extension can increase property value by 10 to 20%, while a conservatory typically adds 5 to 10%. The quality of the build matters significantly in both cases, a poorly finished conservatory can actually detract from value rather than add to it.

Whichever route you choose, MyBuilder makes it straightforward to find local builders and conservatory installers, compare their profiles and reviews, and get quotes from tradespeople who have completed similar projects nearby.

Find extension specialists

Tips to Save Money on Your Conservatory Extension

Getting a conservatory built for less is largely about making smart choices early, before you have committed to a style, a material, or a company.

Most of the meaningful savings happen at the planning stage, not by haggling on the final quote. Here are the decisions that make the biggest difference.

• Choose a lean-to design: The simplest structure requires the fewest materials and the least labour. For most homeowners, a well-built lean-to delivers excellent value compared to more elaborate styles.

• Opt for uPVC frames: uPVC offers strong thermal performance and is significantly cheaper than aluminium or timber. Modern uPVC frames are durable, low-maintenance, and available in a range of finishes.

• Stick to standard sizes: Bespoke dimensions require additional planning and custom materials. Standard sizes are more economical and have shorter lead times.

• Choose double over triple glazing: Unless you plan to use the space year-round in all weathers, standard double glazing provides good insulation at a lower cost than triple glazing.

• Get multiple quotes: Conservatory installation prices can vary by 20 to 30% between companies for the same specification. Always get at least three quotes and check what is and is not included in each.

• Book off-peak: Demand for conservatory installers tends to drop in winter. Booking during quieter months can sometimes reduce costs or lead to better availability.

Find a Conservatory Installer on MyBuilder

It is easy to find a local conservatory installer on MyBuilder. Post your job and available installers in your area can respond with their services and pricing. You can browse their profiles, read reviews from local homeowners, and see photos of previous conservatory builds before making a decision.

All tradespeople on MyBuilder undergo checks at registration, such as ID documents, company details, certifications for regulated jobs and skill assessments, allowing you to hire with confidence.

Find a conservatory installer

FAQs: Common Questions About Conservatory Extension Costs

Do I Need Planning Permission for a Conservatory Extension?

Most conservatory extensions fall under permitted development and do not require planning permission, provided they meet the standard size, height, and boundary conditions. However, if your property is listed, in a conservation area, or the conservatory exceeds permitted development limits, you will need to apply. The current fee for a householder planning application in England is £528. Always check with your local planning authority before work begins.

How Long Does a Conservatory Extension Take to Build?

Most conservatory installations take between one and three weeks from the start of groundworks to completion, depending on the size and complexity of the build. Lead times from order to installation are typically six to eight weeks if planning permission is not required. Solid roof conservatories or more complex designs may take longer.

Will a Conservatory Extension Add Value to My Home?

A well-built conservatory can add 5 to 10% to your property's value, particularly if the space is usable year-round and well-integrated with the rest of the house.

A poorly built conservatory with cheap materials or one that is uncomfortable to use in most seasons is unlikely to add meaningful value. You can browse photos of completed conservatory projects on MyBuilder to see how local installers have approached similar builds and what different specifications look like in practice.

What Is the Cheapest Type of Conservatory Extension?

The lean-to conservatory is consistently the most affordable option, starting from around £8,000 for a basic uPVC installation.

Choosing uPVC over aluminium or timber, double over triple glazing, a polycarbonate over a glass or solid roof, and a standard rather than bespoke design are the most effective ways to reduce costs further. Comparing at least three quotes from local installers helps ensure you are getting a competitive price.

Can I Put a Toilet in a Conservatory?

Yes, but it is more involved than a standard conservatory installation and will affect both the cost and the planning requirements. Adding a toilet requires connecting to the existing soil stack or drainage system, which means groundwork and plumbing work on top of the core build. A cloakroom-style installation, toilet and small basin, typically adds £1,500 to £3,000 to the overall project cost depending on how far the new plumbing needs to run from the existing system.