How much does it cost to turn a double garage into a room?

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Converting a double garage into a functional room has become an increasingly popular home improvement project in recent years. This transformation not only provides additional living space but also has the potential to increase the value of your property. However, before embarking on this journey, it’s essential to understand the associated costs and what the conversion entails.

In this article, we will explore the various elements contributing to the cost of turning a double garage into a room, ranging from structural modifications to interior finishing.

Changing the Garage Door

One of the first and most significant changes in a garage conversion is potentially replacing the garage door. A popular choice is to install patio doors or large windows to create a bright and inviting space. The cost of this change depends on the type and quality of the door or window you choose, with prices ranging from £1,000 to £5,000 or more.


Proper insulation is crucial to creating a comfortable living space. The cost of insulating your garage will depend on the current state of the garage and the level of insulation you desire. Basic insulation can cost between £1,000 and £2,500, while more comprehensive solutions, including wall, floor, and ceiling insulation, can increase the cost to between £2,500 and £5,000.

Timber Frame and Plasterboard

Lining the inside of the garage with a timber frame and plasterboard is essential for creating a finished look. This process also provides the cavity to add insulation. The cost for timber framing and plasterboarding can range from £1,500 to £3,000, depending on the size of the garage and the materials used. You’ll also have to consider the cost of skimming the plasterboard which could add another £1000 – £2000.

Electrics and Lighting

Adding electrics and lighting is a crucial component of the conversion, providing functionality to the new space. This work should be carried out by a qualified electrician to ensure it meets safety standards. The cost for electrics and lighting can vary widely, from £1,000 for basic wiring and fixtures, up to £3,000 or more for more extensive electrical work and high-end lighting fixtures.

Additional Costs

There are also additional costs to consider, such as flooring and skirting, painting, and decorating, and any internal walls you may requre, which can range from £1,000 to £5,000, depending on the quality of materials and finishes you choose. If plumbing is required for a sink or kitchenette, this can add a further £2,000 to £4,000 to the overall cost dependant upon the distance to connect to services etc.

Partial Conversion

For those not requiring a full conversion, there is the option to convert just half of the double garage, maintaining the other half as storage space. This approach can significantly reduce the overall cost depending on the extent of the work required.


Converting a double garage into a room is a substantial investment, with costs varying widely depending on the extent of the work and the materials used.

A very simple conversion with basic finishes can cost around £5,000, while a detailed conversion with high-quality materials and finishes can reach up to £20,000 or more. Opting for a partial conversion can offer a cost-effective solution, providing additional living space while retaining valuable storage.

Regardless of the route you choose, a garage conversion has the potential to enhance your living space and increase the value of your property, making it a worthwhile investment.

Contact us for a no-obligation quote or more information…