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Converting a garage into a room: A step-by-step guide

by | Feb 4, 2023

Home $ A guide on home improvement in the UK $ Best ways to add value to your home in the UK $ Converting a garage into a room: A step-by-step guide

Converting a garage into a room is a fun process that if you are doing it yourself can require quite a bit of work. However, done right, it is a great way to add value to a house and provide some extra living space.

In this step-by-step guide, we will walk you through everything you need to know about converting your garage into a room, from how to assess whether a garage can even be converted, to the construction work.

How to convert a garage into a room step by step

If you’ve made the decision to convert a garage into a room, the below steps should guide you through it. First of all, you should add natural light using windows and finish off by looking at the electricity requirements of the garage.

A garage in a property that is going to be converted

Adding windows

Initially, the first thing to consider is the windows you want to add to the room. This means knocking down walls and getting rid of the door of the garage. 

If the door is particularly expensive, you may be able to sell the garage door and use the funds as capital for the refurbishment of the room.

Typically, because the windows of this new room will be on the ground floor, you’d want to make sure the windows are higher up than usual for privacy reasons – especially if it is a bedroom that is being built.

You can do this by building a wall using breeze blocks and leaving the right gaps for the windows you’re going to use. It is recommended to buy or plan the size of the window you’ll use for the room before this wall is built.

Ventilating a garage space

Ventilating a garage space is hard because when a garage is built there usually is no consideration for the airflow in this space. This is because airflow is usually able to come from the garage door and there isn’t the need for optimised airflow anyway.

This means once the wall is constructed with the right windows, you’d have to add in a fan which is able to extract air from the property. Simple extraction fans are ideal and you may also have to install additional fans on the other side of the garage too.

This all depends on the layout of the space you have. Typically, the fewer doors there are in the garage, the more ventilation you’d need.

Adding insulation to the walls and ceiling

After you have decided on the ventilation for the space, to prevent things like condensation buildup and colder temperatures in the room, it may be necessary to add inn insulation to areas of the garage too.

By planning ahead, you can add insulation in between the breeze blocks of the wall you have to build in replacement of the garage door but there may also be additional insulation that has to be built in the ceiling or potentially the walls.

Whenever a garage is built, it is with the intention that a car will be in there for most of the time and potentially used for storage so it is quite likely insulation will have to be added to a garage.

A garage before it is converted

Adding another floor to the garage

If possible, you could add another floor to the garage if it is particularly high. For instance, if the height of the ceiling is above 5 metres, you could add a floor that has stairs for parts of the room.

Alternatively, you could make the upstairs and downstairs floors completely separate and only be able to access the floor above through the stairs that are already in the property. 

However, this will require you to conduct a lot of work in a property and potentially knock down a lot of the walls in the premises which could be costly and make the buyer go over budget.

Electricity requirements of a garage

A garage typically will need to have at least two sockets added if it is being made into a conventional bedroom. In addition to this, there may be lighting issues that need adjusting too.

For example, a garage will typically have a single light but a bedroom may need to split this wire into a few different outlets to make way for multiple bulbs in the room.

You would also have to consider the additional cost of conducting an EICR test as a result of this conversion and make sure all electrical tests are conducted by a qualified electrician you can find here.

Where should you start when deciding on how to convert a garage into a room?

If you’re not sure if you should convert a garage into a room, there are a few things you can start questioning yourself with so you can comment on the right conclusion.

What may seem like a good idea on paper, upon further consideration could in fact become something you want to avoid for legal reasons or simply because the room size isn’t sufficient such as if you’re converting to a HMO.

Is it legal to convert a garage into a room?

With the right planning permission and the ability to meet building regulations, a garage conversion into a room is completely legal. This means you may need to consider the acoustics of the property, the fire safety, the ventilation and also thermal performance.

Also, while there are recommended building regulations in order to build a garage, this only has to be followed if you’re renting the property out.

So, if you’re the rightful owner to a property, renovate and convert a property as much as you’d like.

Is it worth converting a garage?

Converting a garage is worth it for some but others regret their decision if they don’t consider the things they should do before doing the work.

A garage conversion can add value to a property, create some extra space to enjoy, form a nice DIY project and allow you to increase the rental yield of a property if you’re renting per room.

In the same way, finding out what type of improvements do not add value can also be beneficial so you don’t do any unnecessary mistakes.

However, costs can rack up if you do not plan appropriately and the failure to apply for planning permission and follow building regulations could amount to legal issues.

So, whether converting a garage or not is down to the individual and the deal that they have in mind when converting a garage.

A garage before its conversion into a room

What type of room are you going to convert the garage into?

In the process of creating a garage, there are a multitude of different types of rooms that you can potentially convert into. 

These include:

A kitchen

If the garage is near the kitchen, this is an easy choice for making sure the garage is converted into something useful. You can potentially increase the size of the kitchen or create a kitchen-diner.

The garage space is arguably easier to become a dining room rather than an extension to the kitchen directly because there is a lot of piping and electrical work that has to take place if you are to add a kitchen into the garage.

Living room extension

Living rooms are able to be extended into the garage quite easily. You could make a larger living room or also create a separate room alongside the main living room too.

For instance, you could have a larger living room where the main entertainment in the property happens and then another one where that is perhaps made for quieter use.

A popular choice for homeowners is making the living room into a space that has it all. Include things like a gaming setup, a gym, a TV and a few sofas all in the same room and you can convert into whatever you want at the time.

A bedroom

Bedrooms on the ground floor of a property are certainly rare choices for those converting their garage. This is because of the increased noise that comes from street level and the majority of housing layouts having all bedrooms on the top floor.

This means if you add a bedroom to the ground floor it will disrupt the original setup of the house. Nonetheless, if you already have a bedroom on the ground floor, this will not look so obstructive to the setup of the house.

You have to bear in mind that a bedroom is for sleeping in and if there are other louder activities going on in the ground floor of the house, this will simply make the experience of the person worse.

Not being able to sleep due to disruption and not being able to experience a respectable amount of privacy are all potential issues.

An additional bathroom

Bathrooms are a good choice to install instead of a garage because they will allow a house that has a bathroom on the top floor to then have a toilet on the ground floor too.

This is perfect if you have guests in a property and want to keep the upstairs rooms of the house private while only hosting on the ground floor. Besides, it is simply convenient whenever there are two bathrooms free.

However, a lot of garages are simply too big to solely convert into a toilet or bathroom so it is best to only do this when converting smaller garages or to convert the garage into a bathroom and another type of room.

For instance, an extension for the kitchen and a bathroom could be a good idea or having a small gym with a bathroom attached to it also works well for larger garages needing a combination of spaces.

A garage that has been converted into a bathroom

A gym

Gyms are ideal for those who go to the gym often. Over the years, there are certainly a lot of benefits to having a gym in your own house. First of all, you get to save money on a gym membership if everything is provided in your own house.

As well as this, you will be able to save time travelling if you have a gym in your own house and you can customise the equipment you want in your house too.

What kind of planning permission do you need?

In the process of converting a garage, there usually isn’t the need to ask for planning permission from a local authority as long as the conversion is done within the confines of the walls of the house.

However, if you are extending a garage or using the garage as an annexe for a property, then you’ll need to obtain some level of planning permission from a local authority.

You can find these planning permission laws here.

Should you convert your whole garage?

Most of the time, it works best if you convert the entire garage of a property. If you don’t you would end up with awkward space in between the converted areas of the garage and the area where you haven’t touched for renovation.

When you speak to the contractor who will be renovating and converting a garage or perhaps if you are going to hire an architect, ask them to consider this and ask for their expert advice.

Chances are they would have the knowledge of would have dealt with a property like this in the past so would be able to recommend the right thing for you.

Things you should consider before doing the work

Now, doing a garage conversion is not for everyone despite it appearing quite glamorous and a great way to create some additional space to a property.

This is due to the property owners not considering things like the thickness of the walls in a property, the spatial requirements, the plumbing involved in a property and the cost of renovation.

Thickness of the walls

In the process of converting a garage, there is a lot that you have to do in order to have the right wall thickness. First, you have to work out where the wall is going to be located in the property. 

Afterwards, you have to assign the wall with the relent thickness. For instance, a wall that is on the outside of a property will need to have a larger thickness than one that is a separating wall.

However, there are other factors that impact the thickness of walls too including if there is insulation necessary in the property or if there is a noise barrier that must be installed due to there being noise on the other side of the wall.

Spatial requirements

Another thing you should consider when converting a garage is if the room you’re trying to convert the garage into has the right spatial requirement, before you do any building work.

For example, you don’t want to get halfway through the renovation for a kitchen and realise that there isn’t enough room to add in the dishwasher that you wanted to install.

Planning efficiently is the first thing you should do before you end up having any work done on your property. It could mean that after planning you change the entire room altogether or decide to not convert anything at all.

After all, having some space for a garage is still useful as you’ll be able to store things away in a property and also have room for a car if you have one.


The plumbing requirements of the room you want to convert to should also be considered carefully. Sometimes, you could find that the water requirements for the room will require a lot of.

Kitchens are an example of a room that will need a lot of plugs, whereas a gym will not need anything unless you want to install something like a sauna or a water fountain as part of your space.

The cost of plumbing can therefore impact things quite a bit. If you have to spend an extra £2,000 to hire a plumber to reroute water around a garage, this could change your idea of extending a kitchen altogether for example.

Estimated cost of converting a garage in the UK

The estimated cost of converting a garage is laid out below and based on data from leading garage conversion companies.

Type of garage


Estimated cost

Required time



£7,500 to £13,000

2 to 3 weeks



£14,000 to £25,000

3 to 4 weeks



£13,700 to £18,400

2 to 3 weeks



£25,000 to £36,500

3 to 4 weeks



£20,500 to £29,000

3 to 4 weeks



£36,200 to £58,000

4 to 5 weeks

Converting a garage detached from a main building

If you’re converting a garage away from the main building, you may want to look into the laws around this based on planning permission as a garage like this may fall into the category of an annexe or an outhouse.

Do you need an architect to convert a garage?

Unless you are considering a multi-story conversion or the garage is particularly large and the conversion option particularly complex, there is no need to hire an architect for the work of converting a garage.


In conclusion, converting a garage can be an excellent way to add living space to your home and increase its value. By following the steps outlined in this article, including planning and designing the space, obtaining necessary permits and approvals, and hiring qualified professionals to complete the work, you can transform your garage into a functional and comfortable living area. Whether you choose to use the space as a guest suite, home office, gym, or entertainment room, a well-executed garage conversion can provide you with years of enjoyment and enhance the overall functionality of your home.


What will it cost to convert a garage into a room?

The cost to convert a garage into a room can range from a few thousand to tens of thousands of pounds, depending on the extent of the renovation

What are the most common mistakes when converting a garage into a room?

Common mistakes when converting a garage include poor insulation, inadequate ventilation, and neglecting structural issues

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Donnell Bailey

Property expert

Donnell is a property expert focusing on the property market, he looks at a combination of legislation, information from property managers, letting agents and market trends to produce information to help landlords.