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Converting a Garage into a Granny Flat UK

19 August 2024
garage conversion granny flat

Many garages in the UK are under-utilised. Cars today are larger than they used to be and don't need to be kept inside as much now, so garages aren't as helpful as they once were. Instead, they become messy storage places for bikes, gardening tools, and random junk.


However, most garages still hold a lot of potential. It's typically less expensive to turn an existing structure into a habitable space than to build a new one from the ground up. Typically located beside the main house or as a separate structure, a garage conversion offers an excellent opportunity to create a private and comfortable independent dwelling. This post will explore the advantages and considerations of transforming a garage into a granny flat, as well as some of the important steps you need to take to get your project started.

Why Convert a Garage into a Granny Flat?

Create a dwelling for family members

Converting a garage can give you the space you need to be able to accommodate your loved ones at home, while still giving them plenty of autonomy. They can be a great option for ageing parents and can help you avoid the hefty fees of care homes. They are also helpful if you have adult children staying with you while they study or work.

The value of an additional dwelling

Since a garage conversion increases the amount of liveable space on your property, it is likely to boost the overall value of your home. This means that a garage conversion is a long-term investment that has the potential to improve your home's resale value.


A garage converted into a fully self-contained dwelling also has the potential to become a valuable income source. You could use it as a property for long term lets, providing you with an additional stream of revenue month-to-month. Alternatively, if you live in an area that receives lots of tourists, you could also use your new granny flat as a holiday let.

garage conversion

1 Car Garage Conversion

If you plan to build a separate dwelling, a single-car garage might be too small for your project. It's also important to consider that some of your existing floor space may be taken up by the walls being brought inwards to accommodate amenities such as insulation, water, and electricity.


If your garage is a one-car garage, you should consider options for expanding your new home's footprint or building upward to create additional space. Your plans for your new structure need to be p, as you may encounter resistance from your local planning authority if you intend to make significant alterations to your property to build a granny flat.


Not sure how to fit everything in your new home? We can help you design your new space and guide you through the process of obtaining planning permission for your build. Book a free initial consultation today by entering your details and a line or two about your project on our contact page.

2 Car Garage Conversion

A two-car garage is a more realistic starting point for a self-contained granny flat. It will likely be big enough to fit everything you need, like a kitchen, bedroom, bathroom, and living room, especially if you build up. However, there will still be space limitations, and you will have to think carefully about what rooms you want to include.

garage conversion into granny annexe

Steps to Converting your Garage into a Granny Flat

1. Design and Plan Your Space

Every inch counts in a small space, so it’s important to plan your garage conversion carefully. You should put all your ideas on paper and work with an architect to create detailed planning and construction drawings. These drawings will help you visualise your new space and are essential for getting planning permission from your local Planning Authority.

2. Obtain Planning Permission

Since you intend to use your garage conversion as a separate dwelling, you will likely need to submit a full planning application for your granny flat. We always recommend you speak to a planning expert such as ourselves or directly with your local planning authority before planning or making any changes to your property.

Case Study: Garage Conversion in Matlock, Derbyshire, UK (2024)

garage conversion

We recently helped a client obtain planning permission to convert a garage/former workshop into a two-storey, single-bedroom dwelling with its own garden plot and parking space. This property is suitable for resale as its own unit or for renting out to tenants. This was an exciting step forward for our client.

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3. Obtain Building Control Approval

Once your plans have been approved by the appropriate Planning Authority, you will also need to obtain building control approval. Building control regulations set the minimum standards your renovation must meet to be approved as safe, structurally sound, and environmentally sustainable.

4. Prepare for Your Renovation

After your applications are approved, it's time to start thinking about the logistics of your build. Your garage will need to be empty before work can begin, so it's important to find a safe new space for your things and get the room cleaned and ready for work to begin.


Although garage conversions are generally minimally disruptive compared to other renovations due to their separation from the home, they can still create noise and mess. It's worth considering how the work may impact your routine. If you work from home, consider moving your office to the other side of the house to help prevent any disruption.

5. Start the Garage Conversion

It is now time to begin your renovation project! To ensure a successful outcome, all aspects of the work, including electrical, plumbing, insulation, and drywall installations, should be undertaken by skilled professionals.


You may wish to consider whether the work requires dry weather (such as replacing the roof) or if it can be done during the winter if it's self-contained. Some materials may be cheaper during colder months due to lower demand.


Are you uncertain about how to coordinate your project? We can manage your garage conversion from end-to-end, leveraging our network of trusted contractors to complete each step of the renovation.

garage conversion

6. Add the Finishing Touches

If you're moving a loved one such as an ageing parent or an adult child into your new granny flat, it's important that it is decorated tastefully to feel welcoming and cosy. A stylish interior will also make your garage conversion more attractive buyers or renters.


We can collaborate with either you or the future occupant of your converted garage to create a detailed plan for the interior. Our designers will help you style your space through consultation, vision-boarding, and careful selection of every element, from floor and lighting fixtures to artwork and soft furnishings. We can also create 3d mockups of the interior your granny flat so you can see what each element will look like before it comes to life!

Inspiration for a timeless living room remodel in Other

Overall, converting a garage into a granny flat presents an attractive opportunity for homeowners seeking to provide accommodation for a loved one or generate additional income through a rental property. The feasibility of such a project is dependant on various factors, such as the size, structural integrity, and location of the garage.


At Punchard Group, we can leverage our planning expertise to help you to discern whether a garage conversion is a viable option for your property. We offer comprehensive services that cover every step of the project - from preplanning advice to adding the final touches to the interior. Our expert team can be as hands-on or hands-off as you require.


Discover how we can help you convert your garage into a granny flat by contacting our team. We offer a free initial consultation to help you decide whether we're the right fit for your project - no commitments!