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.

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 you perfect garden living space:

  1. Hire a professional garden room company 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 in the 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 office build guide will show you everything you need to complete this project 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 year 2022 and 2023. There are however a number of different factors that will affect the price of your build. For example, how think 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)£8,500
8m square (4x2m)£9,800
12m square (4x3m)£12,400
15m square (5x3m)£14,700
20m square (5x4m)£17,800
25m square (5x5m)£22,300
Cost of a DIY garden room, built from scratch
Size m2Average Cost £
6m square (3x2m)£8,000
8m square (4x2m)£9,500
12m square (4x3m)£12,000
15m square (5x3m)£14,000
20m square (5x4m)£17,000
25m square (5x5m)£21,500

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.

Will a garden room add value to my property?

In short, yes it will. The value of the building will be reflected in the overall property value so every penny put into the construction will be returned once you come to sell. If house prices continue to rise as they are then you will sure make a profit. Properties with garden rooms are very appealing as they offer additional private living space.

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?

Your garden room cannot take up more than 50% of the total space around your existing house. Otherwise you will require planning permission. 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 yes 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 on a garden office or room. The overall construction of a garden room will be manufactured from timber as apposed to bricks and mortar. House extensions also require solid and deep foundations to secure the weight of the bricks. Garden rooms don’t need the same level of support and therefore the foundations will be less expensive.

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:

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:

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.

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

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. B&Q

Probably not the obvious choice but at they have a decent selection of garden buildings that can be insulated and fitted out for the perfect garden room.

bandq garden offices

4. Robert Dyas

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

robert dyas garden buildings

5. 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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