Imagine unlocking the hidden potential of your outdoor space with a single, transformative addition. A garden room could be the key to expanding your home, providing that much-needed extra living space or a functional home office.
These versatile structures can adapt to many purposes, but with so many options available, how do you choose the perfect one?
Let us guide you through the diverse world of garden rooms and their unique requirements to help you make an informed decision for your property.
What is a garden room extension?
A garden room extension is a small independent building that is placed right in your garden. It is a house addition that is detached from the main house and can be built using multiple construction techniques. However, the most popular garden room extensions today are built with prefab methods, as these offer the most benefits.
Are garden rooms a good idea?
It is usually a great idea to install a garden room in the outdoor space of your property, especially if you have a larger garden, as this is the simplest way to add some extra space to your property. This choice is even more reasonable if you opt for a prefabricated type of garden room as being built in a factory-like environment magnifies the advantages shown by this type of construction.
The main benefits of buying a prefab garden room:
- Fast and clean construction: Prefabrication allows the garden room to be constructed entirely off-site, preserving your outdoor living space and minimizing disruptions to your home life. Moreover, the industrialized construction process significantly speeds up the building timeline.
- Cost-effective solution: Garden rooms are more affordable than expanding an original house as being detached simplifies the construction works. However, opting for a prefab garden room ensures a significantly lower final price due to the cost savings achieved by constructing it in a factory-like environment.
- Good quality: Despite being built faster and cheaper, prefab garden rooms are high-quality constructions, built following the same building codes required by traditional construction. Also, being built in a factory means that every construction step is subject to rigorous quality controls.
- Can be rented out: Renting out your garden room as an Airbnb or other short-term vacation rental can be a great way to generate additional income. The cost-effectiveness of prefab construction means lower initial investment, resulting in a quicker return on investment.
The different types of prefab garden rooms
Garden room extensions are highly versatile and can be used for multiple purposes, from serving as an independent apartment to providing a home office space. Here are some of the most common types of prefab garden rooms:
Granny Annexe
Originally thought of as a solution to offer independent living for elderly family members, this type of garden room provides additional residential space. A prefab granny annexe is usually referred to as a Cabin and it includes one bedroom, a bathroom and a kitchen; as well as all the necessary equipment to provide a self-sufficient residential space and maintain a comfortable environment such as electricity, water and heating systems.

Garden Offices
These are functional spaces built to add the extra workspace you need at home. Garden Offices are designed to improve your work-life balance and tend to be equipped with all the necessary features including a complete bathroom and even a kitchen in most cases.
As a result, these spaces can be used independently without relying on the services offered by the main house.

Get quotes for your prefab project
Take 5 minutes to complete our form and receive quotes from our network of prefab suppliers. It's free, quick, and easy.
ASK FOR QUOTESTiny House
While not the most common type of garden room, Tiny Homes are gaining popularity due to the advantages they offer. Built on wheels, they can easily roll in and out of your garden as needed, serving both as a garden room and a holiday home if desired.
The unique construction of Tiny Homes often results in a more cost-effective solution, as they don’t require permanent foundations. Being moveable constructions allows them to bypass numerous regulations. Therefore, in some cases, buying a tiny house as a garden annexe is a good idea.

What you need to know before acquiring a Garden Room
While garden rooms are quite versatile, there are some differences between the different types of garden rooms. These differences might not be too noticeable in your garden room design and appearance but they can affect the building process.
Do you need planning permission for a garden room?
There is a lot of confusion regarding the need for planning permission when building an annexe in the garden, which comes from the fact that there isn’t just one answer to it. In most cases, granny annexes and garden offices require either planning permission or some sort of licence.
Tiny houses, however, are often exempt from this requirement. For example, in the UK, this type of moveable garden room usually complies with the Caravan Act and needs no planning application.
While this example might apply to other locations, it’s important to note that every country, and even every town, has its own set of regulations. Therefore, the only way to know for sure whether you need planning permission or any other type of license to install a garden room on your property is by consulting with your local planning officers.
Choosing Your Garden Room
To find the garden room that best fits your needs and your property, this is what you should keep in mind:
- Choose a prefab garden room: These have the same features and quality as traditional builds but offer additional benefits such as a lower cost and faster construction.
- Specify your goal: Be clear with the function you want this additional space to offer. For example, are you looking for extra living space or a quiet place to work?
- Consult with the planning authorities: Get to know what the planning requirements for garden rooms in your area are to choose the right type of construction.
- Set your budget: Define a clear budget and see which types and models of garden rooms fit within this value. Keep in mind that the purchase price of a prefab construction is often just a base price and some additional installation costs will be added to the final value.
FAQ
What is the difference between a garden room and a conservatory?
While both are house extensions designed to add some additional space to your main house, they are built differently. A garden room is an independent building detached from the main house while the conservatory is attached to it.
How much does it cost to build a garden room?
The cost of a garden room depends on how it is built and in this case, prefab is better than traditional building. For example, in the UK, a granny annexe built with traditional construction methods costs about £80,000 to £100,000 [1]. Yet, the same type of annexe can be purchased at a much lower price range if prefabricated as the cost of a prefab granny annexe begins at just 17,500€.
What is the maximum height you can build a garden room without planning permission?
The need for planning permission varies from one location to another but let’s take the UK as an example. By choosing a garden room designed as a non-residential space we might be exempt from planning permission as it could qualify under the permitted development rights. In this case, the maximum height permitted would be 4 metres [2].
References
[1]Emma M. (2022, August 31) Cost of Granny Annexe https://www.homehow.co.uk/costs/granny-annexe
[2](2019, September) Permitted development rights for householders (Technical Guidance) Ministry of Communities and Local Government Housing