How much does a garage extension cost?

What is a garage extension?

This type of extension, usually to the side of your home, is built to accommodate a garage and a secure storage space. This can be used for overnight vehicle storage, which may reduce your insurance premiums, and a well-designed garage extension can also provide additional living space.

Creating a garage extension can utilise unused space to the side of your home, as well as adding value to your property.

There are multiple options to maximise the benefits of your extension by adding additional storage areas or even creating a double-height extension with extra living space above.

A garage is an ideal utility space should your family be growing and you find yourselves without room to move inside your home.

What are the benefits of a garage extension?

The primary purpose of a garage is to store a vehicle; this in itself has multiple benefits that may be essential to homeowners in busy urban properties for whom parking is difficult to find, or requires the expense of a parking permit.

Properties with more than one car may find it impossible to find nearby parking for more than one vehicle, and creating a garage provides a private and permanent solution.

Once your garage is built, be sure to advise your insurance provider, as parking overnight in a secure off-road facility is likely to bring down your vehicle insurance costs. If your premiums are high, or you drive a high-value vehicle, this can pay dividends!

Other benefits to building a garage extension include:

• Additional storage space
• Utility areas to free up living space inside your home
• Protecting your vehicle from vandalism, theft or bad weather

What are garage extensions used for?

The beauty of a garage extension is that it does not just have to accommodate your vehicle. If space allows, you can also consider a double garage to provide safe parking for multiple cars.

Other uses that make garage extensions flexible and ideal for expanding your living space include utility areas to add home appliances, washing facilities or storage to the rear aspect of your garage. This is an ideal space to store less aesthetic appliances that you don’t have space for inside, such as chest freezers, washing machines and tumble dryers.

Garages are also perfect for tool storage, providing secure space to safely keep your equipment – garages are far more secure than a garden shed, harder to break into, and perfect for tradespeople whose tools can carry a high value.

Other garages are used for hobby space and to store items like paints, brushes, crafts materials, sports equipment and fitness resources, without creating clutter in your home.

Adding a garage extension increases the value of your property by around £10,000 depending on the area you live in, and for areas with restricted road parking can be a lucrative asset when selling your home.

How much does a garage conversion cost?

The typical garage extension costs between £4,500 and £20,000, and much of the cost will depend on the size of your garage, the accessibility of your site, how complex your design is, and what materials you select.

If your garage makes use of the existing outer wall of your home, this will reduce the costs, whereas erecting a new standalone structure will cost more.

Should you require a home office space, or other internal use then your garage will need glazing and additional lighting, which will also require a higher budget.

Insulation is also an important cost factor – a garage used primarily for storage probably does not require much insulation, but if you intend to use the space regularly, or as an addition that is accessible from inside your home, then it will need to be insulated to avoid draining heat from your property.

What are the important factors to consider when designing a garage extension?

The first thing to consider when designing your extension is the size. Whether you require storage for one car, the size of the car, or whether you want to maximise the size of your garage for future saleability will dictate the footprint you build on:

• A small modern car usually measures around two metres wide and four metres long
• A saloon car is slightly longer, usually just under 4.5 metres
• A people carrier is typically just over two metres wide, and over 4.5 metres long

For example, if you were to build a garage extension of around 2.5 x 5 metres, this would provide space for one small car, or bikes, motorbikes and storage.

An extension of around 3 x 5.5 metres would provide space for one small car with some additional storage space.

A garage extension of 3 x 6 metres would fit a larger car comfortably, and provide extra space for other uses.

Of course, how much space you have to build on may restrict the size of your garage, so it is vital to understand how much room you need, and how much land is available to build on before any works begin. Many 1970’s homes were built with garages that are too small to accommodate any vehicles other than a traditional Mini, so make sure your garage fits your car!

Other considerations when thinking about your design include:

1. Positioning

Most garages are to the side of a property, but you need to decide whether it will be a standalone construction or an extension to your home. A garage extension can be set back, rather than built flush with the front of your house. This provides extra room for the doors and sometimes can enable you to park a car on your driveway as well as inside the garage.

2. Preparation work

Are there any trees rooted or overhanging the area you wish to build upon? If so, these will need to be removed before work, and permission might be required to remove any trees.

3. Maintenance

Does your garage need gutters and draining, and what sort of roof will be easiest to maintain?

4. Space

Is there sufficient space to build a garage on your land? How will the door open; is there enough room for an up and over door to swing out without obstructing the footpath?

Cost factors to building garage extension:

Once you know how large your garage needs to be, and have decided where it will be positioned, the next thing to think about is the materials. These can make a big difference to your budget!

A garage extension with any other uses that require regular access will need:

• Insulation
• Glazing and window frames
• Internal access points
• Electrical wiring, lighting and power points

If you drive an electric or hybrid vehicle, make sure you factor in the cost of purchasing and installing a charging point.

Most garages are made from wood, metal or brick. A prefabricated garage is by far the cheapest option but may have limited designs available and a custom-built garage might be more appropriate to be in keeping with the appearance of your home.

Most pre-fabricated kits are made from wood and metal. The shell itself costs as little as £1,000 and due to the lightweight nature of the structure is simple to build. However, they are not secure when compared to a permanent brick build and have limited uses other than for car storage.

Brick garages are permanent, more secure, and easier to insulate. The cost of a brick garage varies depending on the size and layout but can cost from around £10,000 depending on how much internal work you require.
The doors you choose will also have a big impact on cost. Sectional garage doors are one of the most secure options, or automated doors are a convenient choice. For homes with limited driveway space, a roller door is ideal since it does not lift up and out.

If you opt for wooden doors, these will bump up your budget and do require regular upkeep to maintain their gloss. Steel doors are one of the most popular choices since they are lower cost and require minimal maintenance.

Another option perfect for homes near the sea is glass-reinforced polyester (GRP) or fibreglass. These materials are resistant to corrosion from saltwater so are protected from damage and will last much longer.

Frequently asked questions

How long does it take to build a garage extension?

A permanent brick built garage will take longer than a simple pre-fabricated standalone garage. Typically, this will take around three months.

For larger garages, double-height extensions or more complex designs, this can take closer to six months.

Do I need planning permission?

Many garage extensions do not require planning permission – although it all depends on your design.

If your extension plan falls within the below parameters, it is likely to fall under permitted development (PD), although it is always worth contacting your local planning authority to make sure.

Most outbuildings including sheds, greenhouses and garages do fall under PD so long as:

• The extension does not come any further forward than the front of your home
• The height of the build is no more than four metres
• The extension does not constitute more than 50% of your original outdoor space
• The property is not a listed building, in a conservation area, or on designated land
• The extension does not include any balconies or raised platforms
• The design is similar in appearance to your existing home

Whether or not you need planning permission, you do need to ensure that any new extension adheres to building regulations.

What sort of doors should I choose for my garage extension?

Your garage doors can be a significant proportion of your budget, and choosing the right doors depending on space, maintenance, cost and design.

Some of the choices in garage doors include:

• Up & over garage doors – these are probably the most common doors, are strong and secure, and a cost-effective option. The downside is the space required for the door to open outwards.
• Roller garage doors – ideal for homes without much space, and a compact solution that allows you to drive into your garage without lifting the doors up and out.
• Sectional garage doors – perfect for garages where you need to make the most of the width of the entrance space, and great for insulation.
• GRP/fibreglass garage doors – best suited to locations near the sea for the protection from saltwater damage, and are available in a wide variety of finishes and textures.
• Steel garage doors – can be either retractable or a canopy design.
• Side-hinged garage doors – suited for garages providing utility space, since they provide easy access and can be opened like a regular door to provide easy access when you need access to your equipment.
• Wooden garage doors – a more expensive option, but can provide a great aesthetic finish and have superior insulation properties.
• Automated garage doors – ideal for security since you do not need to leave your vehicle to open the garage, and perfect for disabled homeowners or those with restricted mobility.

What type of garage extension should I build?

Your extension needs to work for you, so think about how you would like to use this space before choosing any designs.

Options include:

1. Attached garages

These are built flush with your property, in the same finish that extends across the frontage of your home.

Most attached garages can be built with your existing wall to save on building costs, and creates a large property footprint.

Attached garages can be single or double, and are easier to use for other purposes since they flow naturally from the inside of your home.

2. Parking garages

A parking garage is either next to, or away from your home, and is often the best option for secure vehicle parking in areas where street parking is unavailable, or permits are expensive.

A parking garage is usually built as a standalone structure from your property and can be built fairly cheaply since utilities, insulation and wiring are minimal.

3. Utility garage

Larger garages provide ample space and are perfect for storing kitchen appliances such as washing machines and larger freezers that you do not have space for inside.

Double garages provide maximal space and allow for a car to be parked with additional storage space to the side or rear.

4. Games rooms

Another popular garage choice is a home gym or games room. If you need plenty of room both to park your car and accommodate a games room, you can opt for a double garage or a larger size single garage.

This has the added benefit of being a flexible storage space which you can adjust as your requirements change.