How Much Does A Garage Conversion Cost In The UK

A garage conversion can be one of the most cost-effective ways to create extra living space without the upheaval of a full extension.

Whether you want an extra bedroom, home office, or utility area, the converting your garage can add real value to your home and transform how you use your existing space.

Of course, before you turn the space into something new, you’ll need to consider how much your garage conversion might cost, and whilst the final cost depends on several factors, including size and what it is you actually want.

This guide answers the most common questions we’re asked when converting garages. It explains the average cost of converting a garage in the UK, what can add to the overall cost, and the key things to consider before starting your project.

What Are The Typical Garage Conversion Costs in the UK?

The simple answer is that the cost of a garage conversion can vary considerably. In truth, there’s no such thing as a truly “average garage conversion.” As conversion specialists, we’re often asked about the average cost per square metre, but that figure doesn’t reflect factors such as the intended use of the new space, the need for storage, or the condition of the existing garage.

The cost to convert a single garage

If you’re converting a single garage, the overall cost will depend largely on how you plan to use the new space. On average, a single garage conversion in the UK typically costs between £10,000 and £20,000, including VAT.

The cost of converting a double garage

A double garage conversion typically starts from £15,000 and can exceed £30,000, depending on the size of the garage and the quality of the chosen finishes.

These estimates are based on turning a standard garage into additional living space like a home office, spare bedroom, or utility room, complete with insulation, electrics, flooring, and decoration.

If you’re looking for garage conversion ideas, check out our gallery of recent projects.

General Garage Conversion Cost

Note: Detached garages or conversions involving bathrooms or kitchens typically sit at the higher end.

What You Need to Know Before You Start Your Garage Conversion

Considering a garage conversion can be an exciting step, but preparation is key to ensuring your project runs smoothly.

Every garage conversion is unique, and understanding what’s involved from the start helps you plan more effectively and manage the overall cost.

Whether you’re turning your garage into a bedroom, additional living space, or simply upgrading your current garage for better storage space, there are a some important things you’ll need to consider before any work begins.

Planning Permission - Sometimes Required

In most cases, you won’t need planning permission for a garage conversion, especially if the work keeps the existing structure intact. However, permission for a garage conversion may be required if:

Your property is in a conservation area or is a listed building
The exterior look is being changed for example, replacing the garage door with a new window or wall
You’re converting the garage into a separate living unit or annexe

If you’re unsure, it’s always best to check with your local planning authority or council before starting your garage conversion project. Doing so can save time, money, and potential complications later on.

This is something that an experienced contractor will be able to support you on.

Party Wall Considerations - Sometimes Required

The type of garage is important in determining if you need a Party Wall Agreement. It’s easy to overlook, but if your garage shares a wall with a neighbouring property, you may need to arrange a Party Wall Agreement before starting any structural work whatsoever.

This legal requirement helps protect both parties’ interests and prevents disputes during your garage conversion project.

Your conversion specialist can often guide you through this process to ensure everything is handled correctly before construction begins.

Building Regulations - Always Required

Even if your garage conversion project doesn’t need formal planning approval, it will almost certainly need to comply with building regulations. These make sure that your garage conversion meets safety and quality standards for:

• Thermal performance
• Fire safety
• Structural integrity
• Ventilation and energy efficiency

Your garage conversion specialist should handle this process for you, making sure the type of conversion, whether it’s an attached garage, integral garage, or a new garage, meets all requirements.

It’s sensible to budget around £300–£500 for council inspection fees, which may add to the cost of your overall project but guarantees the work is fully compliant.

Insurance and Legal

Before you convert a garage into living space, we always advise to let your home insurance provider know, both before and after the work is carried out.

Updating your policy will help make sure your garage conversion project and new living area are fully covered in the event of any issues.

Some mortgage lenders or lease agreements may also require written approval before changes are made, particularly if the project alters the property’s structure or layout.

Checking this early helps avoid complications and keeps your project compliant from start to finish.

What’s Typically Included in a Fixed Price

A well-prepared, fixed-price quote helps you understand exactly what’s included in your garage conversion project.

While every type of conversion is different, a comprehensive quotation from a trusted garage conversion specialist should generally cover the following:

An initial design consultation and site survey to plan the project properly
Any construction work, like adding windows or replacing garage doors
Insulation, new flooring, and internal finishes to create a comfortable, habitable space
Basic electrical work, including lighting and sockets
Plastering, painting, and decorating

Always request a detailed written quote so you can know what you're getting. It’s also worth checking that your quote confirms the work meets safety and quality standards, giving you confidence that your garage conversion will add value and space to your home.

Choosing the Right Contractor

Look for builders with experience in garage conversions, especially in your local area. Ask for:

• A clear breakdown of what’s included
• An agreed timeline
• References from past clients
• Proper insurance and certifications

A good contractor will handle building control, coordinate the trades, and guide you through every step.

Ready to Start Your Garage Conversion?

At Pro Assist Property Services, we’ve been converting garages since 2018 across Bedfordshire, Hertfordshire and Buckinghamshire. We offer free site surveys and detailed, fixed-cost quotes so you can move forward with confidence.

Book your free consultation today and start transforming your space.