Garage Conversion vs. Extension: Which is Right for Your Home?

Deciding between a garage conversion and a traditional extension is a common dilemma for Devon homeowners. Both options effectively solve the need for more square footage, but they differ significantly in terms of budget, speed, and long-term impact on your property’s value.

At V3 Build, we have spent 25 years delivering both types of projects. This guide breaks down the core differences to help you choose the best route for your lifestyle and investment.

Garage Conversion: The Fast and Budget-Friendly Option

A garage conversion is often the most efficient way to gain living space because the primary structure—the walls, floor, and roof—is already in place.

The Pros

Converting a garage is typically the most cost-effective home improvement. In 2026, a standard single garage conversion in the UK averages between £10,000 and £20,000, significantly lower than the cost of a new build. Because the work is largely internal, it is also much faster, often taking just two to four weeks to complete. In most cases, these projects fall under Permitted Development, meaning you may not need full planning permission.

The Cons

The most significant drawback is the permanent loss of sheltered parking and storage. In urban areas like Exeter or Plymouth where off-street parking is a premium, this can occasionally impact resale appeal. You are also limited by the existing footprint and ceiling height of the garage, which may restrict how you can use the space.

Traditional Extension: The Flexible and High-Value Route

If you have specific layout requirements or need a substantial increase in space, a traditional extension is the superior choice.

The Pros

An extension offers total design freedom. You can choose the exact dimensions, window placements, and connection points to your existing home, allowing you to create the large, open-plan kitchen-diner that modern buyers prize. From an investment perspective, an extension that adds significant square footage or extra bedrooms often provides a higher return on investment (ROI) than a conversion, sometimes boosting property value by over 20%.

The Cons

The primary hurdles are cost and time. A single-storey extension usually starts at £1,800 to £3,000 per $m^2$, with a total project cost often exceeding £45,000. These projects require foundations, drainage, and structural work, which can take three to six months and cause significant disruption to your garden and daily life. You are also much more likely to require full planning permission.

Comparison Summary (2026 Estimates)

Garage Conversion: Average cost is £10,000 to £20,000. Typical duration is 2 to 4 weeks. Value increase is often 10% to 15%. Best for home offices, gyms, or playrooms.

Single-Storey Extension: Average cost is £45,000 to £90,000. Typical duration is 3 to 6 months. Value increase is often 10% to 20%+. Best for large kitchens, dining hubs, or multiple new rooms.

Making the Decision

The right choice depends on your priorities. If you need a dedicated workspace or a guest bedroom quickly and on a modest budget, a garage conversion is an excellent solution that utilizes “dead space.” However, if your goal is to fundamentally transform the flow of your home and you have the garden space to spare, an extension is a better long-term investment.