Oak framed garage with room above

When looking to expand their houses, many people across the UK choose to build an extension above their garage. This is often the most cost-effective way to add to your property, as foundations and structures are already in place, allowing for a comparatively cheap build. Adding a single or double bedroom extension above a garage can add up to 15% to the value of your home.

However, many people have concerns about building extensions above their garage. They worry about whether their garage can support an extension above it, how much it would cost, and whether they’ll need planning permission for the build. In this article, we address the big question people might have about adding an extension above their garage.

Can My Garage Support An Extension Above It?

timber frame garage with room extension above

It is vital to ensure that your garage can safely support an extension above it. 

Your local council should have blueprints on hand for your property, showing the depth of your foundations. The best case scenario for adding an extension is for your garage to have been constructed alongside the house. In situations where you do not have access to housing documentation, it may be necessary to have a trial hole dug outside your house for the foundations to be checked.

The other major concern would be whether the walls of your garage are capable of supporting an extension above it. The shape and thickness of walls will need to be checked by a structural engineer, as many garage walls are not built to an equivalent thickness with the main house, and therefore may be unable to support the weight of an extension above them. As with foundations, it is vital that you seek professional confirmation that your garage is suitable for an extension above it.

Older garages are unlikely to have the load bearing necessary to support another floor. In such cases the only way you would be able to get an extension above them would be to replace the garage entirely.

It’s important to consider the floorplan of your new garage extension. If you are building over a single garage the amount of floorspace you will have is quite small (2.8 x 5m roughly), which may be too small for an adult bedroom. It’s worth thinking about how the extension will impact the rest of the house, checking if it will block existing windows or limit light to other rooms.

What Is The Cost of An Extension Above My Garage?

3 bay garage with room extensions above

The cost of an extension above a garage can vary, based on whether or not work is needed on your foundation or walls, the size of the extension, and whether or not you’ll be building an ensuite.

A rough estimate for the cost of extensions above garages is around £1000 – £2000 per square metre, so an extension over a single garage would start at around £20,000 for an uncomplicated build. But there will be additional costs if your garage walls or foundations can’t support the extension above them, which can be expensive. A new foundation would be about £2250, while garage walls will set you back £3900 for a basic garage.

An extension above a garage is an investment in your home, and it’s vital that you carefully plan in advance and understand the associated costs.

Do I Need To Get Planning Permission For an Extension Above My Garage?

garage with room above

Adding an extension above your garage in the UK will usually require planning permission. Every local authority has a ‘House Extension Design Guide’ which will detail the terms proposed extensions will need to meet to be granted planning permission. This may involve building materials, the size of your extension, and how it will fit in with neighbouring buildings. Certain protected buildings may be prohibited from building extensions, as well as buildings in conservation areas or open countryside.

Your design for an extension above a garage will have to meet local regulations. This is why it’s vital to work with an architect who understands them and can help you construct an extension that meets the legal requirements.

Another important factor to consider is how the extension above your garage will affect your neighbours. There will likely be restrictions in the design guide about how closely you can build to their property, and on building windows that intrude on their privacy. In addition to legal requirements, it is a wise idea to talk to your neighbours before pursuing alterations to your property and making sure that they are not going to be inconvenienced by them.

Cost wise, a two story garage from The Garage Specialists will be considerably cheaper than building an extension above your garage. While you may still need to apply for planning permission, the time frame for planning, construction, and building will be considerably shorter than an extension to your house.  Our products come with a 10-year guarantee, and we can start production as soon as you place an order, shipping to anywhere in the UK.

Looking For Alternatives To an Extension Above Your Garage?

At The Garage Specialist, we sell a range of high quality two story garage kits in bespoke designs. Our high quality range includes single or double garages with rooms above, and stylish timber framed bay garages with rooms above (in double, triple, or quadruple bay sizes). We also offer bespoke designs for our customers, at no extra cost.

Our products are built in the UK from sustainably sourced oak and Douglas fir timber, and are easy to construct at home, even for DIY beginners. Our experienced carpenters use state of the art technology to ensure the quality and strength of our products, cutting each piece with precision accuracy.

Get in touch today.