How Much Does A Garden Room Cost? A UK Price Breakdown

The average garden room costs about £5,000 to £44,000, depending on its size and specification. Size and specification vary wildly. So, the costs also vary wildly, sometimes reaching up to £150,000, however, this is not the typical cost.

That’s why you can only find out how much it costs to build a garden room after discussing the specifics with a professional installer. So, we will not bother with exact figures. Instead, we will focus on breaking down garden room costs. So, you know what to expect financially.

How Much Does It Cost to Build A Garden Room?

Garden Room Price Guide:

Garden room sizePrice rangeAverage price
2.5m x 1.8m£5,000-£25,000£15,000
3m x 2.5m£8,000-£30,000£19,000
4m x 3m£15,000-£35,000£25,000
5m x 4m£20,000-£44,000£32,000

Quality of finish will massively influence the cost per square meter.

What’s Included In The Price Of A Garden Room?

The prices above should be enough to build a garden room of those sizes. However, that’s not always the case for garden room prices on official websites. Here is a way to look at it. The process of building it yourself can be divided into three aspects.

  • Manufacturing/supply: constructing or supplying the garden room or its components.
  • Delivery: transporting the garden room or its components to the site (i.e., your property).
  •  Installation: installing the garden room and its base, and connecting electricity and other utilities.

Most of the garden room prices on the official websites won’t cover all three aspects. For example, bare-bone garden room costs will probably only provide the following.

  • A body (roof, walls and floor, usually with insulation)
  • Interior and exterior cladding for the body
  • Windows and doors (usually energy-efficient double glazing)
  • Locks for the doors and windows
  • Flooring
  • Internal and external wiring for lights and sockets

These alone aren’t enough to build a garden room. The following are missing.

  • Delivery cost
  • Installation cost
  • A base/foundation for the garden room
  • Electrical hookup to power 
  • Heating

There are two reasons that companies don’t include these five in their starting garden room prices. Firstly, they might offer them as optional packages. Secondly, they might not offer them at all. If it's a case of reason two, you can simply hire another person or company for those particular tasks.

This is why you should always ask what a package includes. Whatever the project, get written quotes. Confirm the specifications of the garden room and find out if those garden room costs include delivery, installation and VAT.

Specification determines what costs cover. A garden room is either low, medium or high spec. Garden building costs will be higher as you move up these categories. However, so will the amount and sophistication of features.

In a way, this is where you will find an accurate answer to the question of how much doesn’t it cost to build a garden room. Here is a table comparing two garden rooms. Garden room A is low spec, while B is more sophisticated.  

Materials Used:

FeatureGarden room A (Low spec)Garden room B (High Spec)
InsulationNo insulation or mineral wood and cavity slab insulationPIR insulation
Building materialuPVC or aluminiumHardwood
HeatingPanel heaters and digital electric radiatorsUnderfloor heating
Roof typeSolid roofRoof lantern
External claddingThermowoodHardwood
Interior liningMDF boardsGraphite grey wall tiles
Roof coveringAsphalt finishesEPDM rubber or insulated steel panels
FlooringSkirting boards or laminate flooringHardwood
Data cablingNot includedIncluded

Garden room B is high spec. It is more sophisticated and feature-packed. However, it will also result in higher room costs. Do note that both garden rooms A and B are mere examples. They are not replicas of units by any specific garden room company. 

However, most garden room companies do have similar units on offer. Most companies will also have options for upgrading and customising their basic units. Obviously, this will naturally result in higher garden room costs.

This part of our conversation brings up the matter of custom-built vs bespoke garden rooms. Most companies will offer both. However, garden room costs will usually be higher for bespoke units. Still, bespoke garden rooms are cost-efficient for people with specific needs.

For example, your installer can design a garden room that suits the dimensions of a garden space or your specific needs. For example, imagine you want the garden room as an extra kitchen. In this case, your installer could fit the garden room with kitchenettes, worktops, sinks, plumbing, etc.

The options are limitless. Other examples include asking your installer to add internal partitions or more windows and doors, etc. Don’t forget that these will increase garden room costs. 

Additional Garden Room Costs To Consider

Here are the most common additional costs of building a garden room.

Building Regulations and Planning Permissions

Garden rooms are permitted developments. Therefore, you don’t need planning permission. However, this only applies if you adhere to rules about the garden room’s size, placement and functionality. 

For example, the garden room can’t be bigger than 30 square metres, taller than 2.5 metres or used as a separate living space. Breaking these rules requires planning permissions and building regulation approval.


There are two jobs in this category: site levelling and survey. You can’t build a garden room on uneven grounds. It will cause cracking, wrapping and shifting. Your garden room’s site must be level to at least 200mm.

Soil surveys help you and your installer determine the ideal garden base for a site. Surveys are crucial when using a ground screw garden room base. Both site levelling and surveys will increase costs.

The foundation is important, where is the garden building going to be placed? If there is an existing concrete foundation that will be adequate this will bring the costs down.

Electrical Connection

We have talked about this job earlier. It’s common for garden office installers to leave this out of their quotes and starting prices. So, you will probably have to hire an electrician separately. This increases garden room costs. 

DIY Garden Room On A Budget

Installation alone makes up 20-25% of garden room costs. So, DIY installation is a great way to save money. It’s also not that difficult if you get a prefabricated garden room and let someone else build the base. You can even save more by building the garden room from scratch. You just need the right experience, tools and time.

However, professional garden room installers have their benefits. They will likely do the job faster and better. They will also offer warranties. So, professional installation is worth every penny, even if it's just to save you some time and stress.

Why You Should Invest In A Garden Room

Here are four reasons to get a garden room.

A Cost-efficient Alternative to Traditional Home Extensions

Garden rooms cost £5,000 to £44,000, while traditional extensions cost £75,000 and £250,000. Yet, a garden room can serve most of the same functions. It will also last for a minimum of 30 years. Most garden room companies will even offer a warranty of 10 years.

Compared to a typical extension adding a garden room is much more cost-effective. A garden building could even be a fully insulated annex, subject to planning approval. A loft conversion will potentially put off older buyers, for example.

Quick Installation 

It takes just 1-3 days to install a garden room. Meanwhile, it could take weeks or months to build a traditional extension. 

Allows You to Make the Most of Your Garden Space

Garden rooms let you enjoy your garden year-round. Only orangeries and conservatories have similar benefits. However, this is only possible if the garden building has insulation and heating.

Improves Value To Your Home

A garden room adds 1.5 times its cost to a property’s value. It can also attract buyers when you put that property on the market. Not only does it add value, it allows flexibility for new families looking at your home.

For example, if you have a garden gym, or a garden office, or even just the flexibility of extra space to have both. This will make your property appeal to more people.


In the UK, garden rooms cost around £5,000 and £44,000, depending on their sizes and specifications. Specification, especially, is crucial. It’s the difference between getting the perfect garden room or one that barely serves your needs.

So, focus on the specifics when talking to a garden room company. This won’t just help you get the best possible garden room. It will also help you detect hidden and additional costs. These two add a lot to garden room prices. 

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