garden room interior sofa

How much does a garden room cost in 2022/23

We’re all well aware that prices for most things have increased in 2022 due to a number of factors. Building materials in some cases have nearly doubled from prices just 4 years ago. With living costs still rising month by month it can be a difficult time for many families. Hopefully though, this doesn’t mean that building projects need to be put on hold, we just need to think about how we can keep the costs down. If you’re thinking of creating some extra space at home, whether it’s a dedicated office workspace, a hobby room, games room, gym or yoga studio then here are some tips on how you can achieve this with a limited budget. Within this post, I’ll answer some of the most common questions about garden rooms and take a look at how much a garden room costs in the years 2022 and 2023.

garden room interior

What type of building options are there for a garden room?

The way I see it, you have three main options to create your perfect garden living space:

  1. Hire a professional garden room company and interior designer to build your perfect space. This is the most expensive option but takes away all the pain from you. You’ll be provided with a long lasting building that has been professionally constructed and signed off.
  2. Buy a pre-fabricated garden room kit that you construct yourself. If you have a few basic DIY skills then this is a very viable option and will save you thousands off the price of hiring professionals. The main thing you will require is time. Expect to spend between two weeks and a month to build this yourself.
  3. Build a garden office from scratch. You’ll need a larger skillset and more specialised tools but again, it’s completely achievable. You’ll save a little more money again but expect to spend even more time building this yourself. My garden room build guide will show you everything you need to complete this project to a professional standard yourself.

It will be up to you which one of these options is right for you. Think carefully about how much time you can dedicate to a project like this and what you budget is.

How much does a garden room cost per square meter?

In the tables below I’m going to give a rough idea of what you should expect to pay for a garden room in the years 2022 and 2023. There are however a number of different factors that will affect the price of your build. For example, how thick the insulation is, how many power sockets you want, will you have double glazing windows and doors, how many doors and windows will you have? My pricing will be based on an average setup.

Pricing will include:

  • Foundations/base
  • Building
  • Insulation for floor, walls and roof
  • Electrics
  • Double glazing doors and windows
  • Internal finishing (plastering)
Cost of a garden room when hiring the professionals
Size m2Average Cost £
6m square (3x2m)£20,600
8m square (4x2m)£23,200
12m square (4x3m)£26,800
15m square (5x3m)£28,500
20m square (5x4m)£33,200
25m square (5x5m)£40,200
Cost of a prefabricated garden room as a DIY build
Size m2Average Cost £
6m square (3x2m)£4,800
8m square (4x2m)£5,800
12m square (4x3m)£6,200
15m square (5x3m)£8,800
20m square (5x4m)£11,800
25m square (5x5m)£14,600
Cost of a DIY garden room, built from scratch
Size m2Average Cost £
6m square (3x2m)£4,200
8m square (4x2m)£6,200
12m square (4x3m)£5,800
15m square (5x3m)£8,200
20m square (5x4m)£11,000
25m square (5x5m)£14,000

As you can see the DIY building from scratch is the most cost effective method. You can build a pretty building for a fraction of the cost of a professional build. Don’t forget to think about some of these other costs:

  • Furniture
  • Landscaping, finishing the grounds around the building
  • Curtains, blinds etc.
  • Delivery
  • Potential planning permission application

What is the cheapest way to build a garden room?

As we can see above the cheapest way to build a garden room is to build it yourself from scratch. You can look at my 12x10ft shed plans to see a basic outline for the construction. Adding insulation and electrics afterwards is another ways to keep your costs down. Windows and doors can be purchased second hand or can be found cheap on sites like Wickes. The benefit of building your own from scratch is that you can make it to your exact specifications and size.

3d shed plans

If you feel like you don’t quite have the time or skill level then a great option is to buy a prefabricated building and add your own insulation and electrics. I built my own log cabin garden office which you can read about here. It goes into detail about the construction process of the base and main structure.

Here’s a look at one of my fabricated garden buildings. It’s a BillyOh Kent garden office which I have insulated and plastered inside for a warm, comfortable, modern finish.

Will a garden room add value to my property?

Garden rooms can potentially add value to a property, but it ultimately depends on the specific circumstances of your property and the local market. Here are a few factors that could affect the value that a garden room adds to your property:

  • Size and quality of the garden room: A larger, high-quality garden room that is well-built and attractive may be more appealing to potential buyers and therefore add more value to your property.
  • Location of the garden room: A garden room that is located in a prominent area of the garden, such as near the house or in a well-manicured part of the garden, may be more valuable than one that is tucked away in a less visible location.
  • Use of the garden room: A garden room that serves a useful purpose, such as a home office or a guest room, may be more valuable to potential buyers than one that is used for storage or as a workshop.
  • Demand for garden rooms in your area: The value that a garden room adds to your property may depend on the demand for such features in your local real estate market. If garden rooms are particularly popular in your area, a well-done one may add significant value to your property.

It’s worth noting that adding a garden room to your property can also be a good investment for your own use and enjoyment, regardless of whether it adds value to the property. If you are considering adding a garden room, it may be a good idea to talk to an estate agent or appraiser to get a sense of the potential impact it could have on the value of your property.

Can I live in my garden room?

Converting your existing garden room or building a garden room with full facilities is entirely possible should you want additional accommodation. You will however need planning permission to make this happen. Planning applications can cost as little as £135 depending on the circumstances. You can find out more and get an exact cost on the UK planning portal fee calculator.

garden room bedroom annex

Costs for these types of buildings, known as an annex, tend to be much higher due to the works required to install the facilities. Toilets, showers, sinks etc. all need waste pipes fitted and you’ll need a boiler for hot water. This could require gas or an expensive electric boiler fitted. You can easily add £12,000 to the cost.

Technically you are not allowed to use your garden room as a dwelling. It cannot legally be used to sleep in without the proper planning consent. Even if it doesn’t have facilities!

How big can a garden room be without planning?

In the United Kingdom, there are no specific size limits for garden rooms when you have the correct planning consent in place. However, there are a number of rules and regulations that you will need to follow when building a garden room, and these can vary depending on the location of your property and the size and nature of the structure you are planning to build.

Generally speaking, you will not need to apply for planning permission for a garden room if it meets all of the following criteria:

  • No outbuilding on land forward of a wall forming the principal elevation.
  • Outbuildings and garages to be single storey with maximum eaves height of 2.5 metres and maximum overall height of four metres with a dual pitched roof or three metres for any other roof.
  • Maximum height of 2.5 metres in the case of a building, enclosure or container within two metres of a boundary of the curtilage of the dwellinghouse.
  • No verandas, balconies or raised platforms (a platform must not exceed 0.3 metres in height)
  • No more than half the area of land around the “original house”* would be covered by additions or other buildings.
  • In National Parks, the Broads, Areas of Outstanding Natural Beauty and World Heritage Sites the maximum area to be covered by buildings, enclosures, containers and pools more than 20 metres from the house to be limited to 10 square metres.
  • On designated land* buildings, enclosures, containers and pools at the side of properties will require planning permission.
  • Within the curtilage of listed buildings any outbuilding will require planning permission.

If your garden room does not meet all of these criteria, you may need to apply for planning permission before you can build it. It’s always a good idea to check with your local planning authority before you start building a garden room to make sure that you are following all relevant rules and regulations.

You can read more of the planning permission guidelines on the planning portal website. It’s important to ensure you stick within these regulations or your garden room could be dismantled. It does happen!

Interactive house planning portal UK

Is a garden room cheaper than an extension?

Generally speaking, a garden room will tend to be slightly cheaper to build than a house extension. This is due to the type of building materials used in a garden room. Garden rooms are typically built using prefabricated panels or modular construction techniques, which makes them faster and easier to build than traditional extensions. They are also usually constructed using lightweight materials, such as timber or steel, which makes them less expensive to build than brick or block extensions.

Additionally, house extensions require solid and deep foundations to secure the weight of the bricks, while garden rooms don’t need the same level of support and therefore the foundations will be less expensive. However, the cost of a garden room will depend on a variety of factors, including the size, materials used, and the complexity of the design. It’s a good idea to get a quote from a contractor to get a more accurate idea of the cost of building a garden room or an extension.

How do I get electricity to my garden room?

Electricity is an important factor when it comes to your garden room. You’ll want to power your home office, TV or gym equipment. A lot of the wiring can be done by yourself but it will all need to be signed off by a qualified electrician.

Armoured cable will need to be used to run the power to your garden building. This is available it different thicknesses so you will need to make sure you get the correct size based on the amount of power you intend to consume and the distance run. You’re always better off speaking to an electrician to get this right.

consumer unit garden room

The cable should be run directly from your consumer unit with a dedicated RCD. You will then need a small consumer unit installed in your garden room. This will then branch off to your lighting and sockets.

The overall cost of the electrical wiring will range from £400 – £1500 plus the electrician fee. Here are some examples of electrical cabling required to complete a basic garden room:

  • Armoured cable 3 core (2.5mm x 25m) – £50
  • Small metal consumer unit – £30
  • Socket twin and earth wiring loom 2.5mm x 50m – £42
  • Dual USB sockets – £13 each (6 total – £78)
  • Dual socket backbox – £4.20 each (6 total – £25.20)
  • Lighting twin and earth wiring loom 1.5mm x 25m – £16.80
  • Electrical cable junction box – £2.50
  • Light switch – £2

You’ll also need to decide what lighting you want for both the interior and exterior which can cost another £100-£300.

down light interior finish

Can I build a garden room myself?

With a small list of tools and a lot of patience most people can build their own garden room. There is a lot of information on this site that will help you plan and build your own garden office or room. Here is a list of basic tools that I feel would be required:

  • Mitre saw
  • Hand saw
  • Combi drill driver set
  • Tape measure
  • Set square

If you’re handy with some of these tools and have completed some of your own DIY projects around the house then there is no reason why you can’t build your own garden room and complete it to a reasonably high quality.

Here are two of my most recent garden office projects. They include step-by-step instructions with detailed images.

garden office 2
Build your own garden office
garden room exterior
BillyOh garden room build

How do you build a garden room?

You can read my in depth construction guides for more detail here:

The construction methods listed here and for most garden rooms is a basic timber frame built on a timber frame base or solid concrete base. The roof construction is normally and apex or flat sloping covered with a waterproof material.

purlins fitted

Finishing the interior of the garden room can vary depending on your budget but for most they will be plasterboard with a plaster skim. Some may decide to go with a timber clad interior but for a contemporary finish a painted plaster will be best.

Do garden rooms need foundations?

Foundations help support your building from sinking into the ground and becoming unstable. Most garden rooms will not require deep foundations and a suitable solid concrete bed with a depth of about 100mm will be sufficient. Many of my garden buildings have been constructed on a sturdy timber frame. This will help reduce costs but may reduce the life of the overall structure. All of my building timber frame bases are treated with creosote. This will add many years life to the timber frame.

The other two options for a foundations would be either a solid cement base or a patio style base.

How do you insulate a garden room?

There are a number of different insulation manufactures out there and it will be up to you which one to use for your garden room. If you are intending to use your building all year round then the thicker the better. Just remember, this is going to reduce the available space on the inside of your building. You can always factor this in with your plans and think about this when designing your building.

I used a Rockwool thermal and acoustic insulation on my garden office build as I wanted to also protect against the noise levels. This does add a little cost to the build but truly gives a private area where you can make a little noise.

Here are a few options worth considering:

For the insulation I decided to use Rockwool RWA45 (50mm) slabs because they offer both excellent thermal and acoustic properties. Thermal conductivity: 0.035 W/mK 

For extra acoustic soundproofing consider going for the Rockwool RW3 or RW5 but this application is best suited for sound/recording studios, not general office use.

For general thermal insulation consider:

  • Kingspan TP10 Insulation Board (2400x1220x50mm) – Expensive but these large boards are great thermal insulators, easy to cut and provide good coverage for larger wall cavities. ~£45 per board. Thermal conductivity: 0.022 W/mK
  • Kay Metzeler General Purpose Polystyrene EPS70 – (2400x1200x50mm) – The cheapest option but not a great acoustic insulator, and it’s not fire resistant. ~£16 per board. Thermal Conductivity: 0.038 W/mK

You can read my full guide here: How to insulate a garden room, office or shed

garden room insulation

Where can I find the best pre-fabricated garden rooms?

The great thing about prefabricated garden buildings is the flexibility and potential for upgrading. Each building listed below is ideal to quickly build the main structure whilst giving you the ability to easily insulate and upgrade as you feel necessary.

  1. Garden buildings Direct

A great selection of suitable garden buildings that can be adapted into an insulated garden room. I purchased the Kent Garden Office which was ideal for this project and very cost effective.

garden buildings direct garden offices

2. Tiger sheds

Tiger shed also provide a good selection of well constructed garden buildings that can be adapted to suit your garden room needs.

tiger sheds garden buildings

3. Robert Dyas

Specialists in everything garden Robert Dyas have a decent selection of garden rooms and buildings ideal for adapting.

robert dyas garden buildings

4. BillyOh

Closely related to Garden Buildings Direct is BillyOh. They also offer a fantastic range of buildings that will provide the perfect building blocks to get your garden room under way.

billyoh garden buildings


Hopefully this article has answered your questions when it comes to garden rooms and garden offices. There are many ways you can save hundred or even thousands on this project. With a few DIY skills and tools you can build an amazing building that will last for years. If you don’t feel like you have the correct skills then there are many professional garden room companies out there. My advise would be to select a company based on their feedback. Selecting a popular company might mean longer waiting times but you’ll get a well built product you can be proud of.

If you have any further questions on this subject then please feel free to leave a comment below and I’ll get back to you asap.

Thanks for reading


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