If your home is starting to feel too small, there are several ways you can create additional space.
Two of the most popular options are a garage conversion and a house extension.
Both can transform your home, but they are very different projects. The right choice depends on your available space, budget, property layout and what you want to achieve.
So, should you convert your garage or build a house extension?
Let’s compare the two options.
What Is a Garage Conversion?
A garage conversion involves transforming an existing garage into usable living space.
Because the structure already exists, the amount of construction required can be significantly less than building a new extension.
A garage could potentially become:
- A bedroom
- Home office
- Gym
- Playroom
- Guest room
- Utility room
- Living space
- Hobby room
Stefan’s Building provides garage conversions across Cambridge and Cambridgeshire, with previous projects including conversions into offices and rooms with en-suite facilities.
What Is a House Extension?
A house extension creates additional space by physically extending your existing property.
Extensions can be built in a variety of ways, including:
- Rear extensions
- Side extensions
- Side-return extensions
- Kitchen extensions
- Bathroom extensions
- Wrap-around extensions
- Single-storey extensions
- Double-storey extensions
This gives homeowners considerably more flexibility over the size and layout of the new space.
Stefan’s Building specialises in bespoke house extensions throughout Cambridge and Cambridgeshire.
Which Is Cheaper?
In most situations, a garage conversion will cost less than building a new extension because the basic structure is already there.
Current UK cost guides put a typical garage conversion at roughly £10,000–£20,000 for a standard 16m² integrated or attached garage, although more extensive projects can cost more.
For house extensions, current UK guides commonly use around £1,800–£3,000 per m² as a broad starting point before VAT and depending on specification.
However, cost shouldn’t be the only consideration.
A garage conversion might be cheaper but provide less space than the extension you actually need.
Garage Conversion vs Extension: Space
If you need a relatively modest amount of additional space, a garage conversion could be ideal.
For example, an integrated single garage could provide enough room for:
- A home office
- A small bedroom
- A gym
- A playroom
But if your goal is to create a large open-plan kitchen and dining area, an extension is likely to provide a much better solution.
Garage Conversion vs Extension: Design Flexibility
A house extension generally provides more flexibility.
You’re effectively creating new space around the existing building, which means you can design the size, shape and layout around your requirements.
A garage conversion is constrained by the existing dimensions of the garage.
This doesn’t mean a garage conversion can’t be bespoke, but there are physical limitations.
Garage Conversion vs Extension: Garden Space
One major advantage of a garage conversion is that it doesn’t necessarily take away garden space.
If your garage is already part of the property, you’re making better use of an existing structure.
A new rear or side extension, however, will generally reduce the amount of external space available.
If you have a relatively small garden, this could be an important consideration.
Garage Conversion vs Extension: Planning Permission
Planning requirements differ between the two options.
A typical internal garage conversion may not require planning permission where the garage isn’t enlarged and the work falls within the relevant rules. Greater Cambridge Shared Planning specifically states that planning permission is not usually needed for a garage conversion where the work is internal and the garage isn’t enlarged.
House extensions can also benefit from permitted development rights, but the rules are more involved and depend on factors including the size, height and position of the extension.
If the work doesn’t meet the permitted development criteria, a planning application will be required.
Garage Conversion vs Extension: Building Regulations
Regardless of whether you need planning permission, Building Regulations may apply.
This is particularly important when converting a garage into habitable accommodation.
The conversion may need improvements to:
- Insulation
- Damp protection
- Ventilation
- Fire safety
- Structural performance
- Electrical systems
- Heating
- Energy efficiency
Planning permission and Building Regulations are separate requirements.
Which Adds More Value?
There isn’t a universal answer.
The value of an improvement depends on the property, location, quality of the work and what buyers in the local market are looking for.
A well-designed extension can significantly increase the usable floor area of a property.
A garage conversion can also be valuable if the existing garage is underused and the additional room is more useful to the homeowner or future buyer.
However, you should think carefully before converting a garage if parking is limited or off-street parking is particularly valuable for your property.
Which Option Is Right for You?
A garage conversion could be the better option if:
- You already have an unused garage
- You want to keep costs lower
- You need one additional room
- You don’t want to lose garden space
- You want a relatively straightforward project
- You don’t need a major increase in floor area
A house extension could be better if:
- You need considerably more space
- You want a larger kitchen
- You want to create an open-plan living area
- You need multiple additional rooms
- You want greater flexibility over the layout
- You have sufficient garden or side space
Can You Combine the Two?
In some circumstances, homeowners may be able to combine a garage conversion with other building work.
For example, a garage could become an internal room while an extension creates additional kitchen or living space.
The feasibility will depend on the property, available space, structural requirements and planning considerations.
Talk to an Experienced Cambridge Builder
Deciding between a garage conversion and house extension is easier when you understand what is realistically possible on your property.
Stefan’s Building provides both garage conversions and house extensions in Cambridge and Cambridgeshire, alongside architectural and structural design services. This means your project can be considered from both a design and construction perspective.
If you’re unsure whether a garage conversion or extension is right for your home, speak to Stefan’s Building about your requirements.
The team can help you assess your options and determine the most practical way to create the additional space you need.