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Garage Conversion Design Services

Transform your underused garage into valuable living space. Whether you need a home office, extra bedroom, playroom or self-contained annexe, a garage conversion is one of the most cost-effective ways to add space to your home.

Converted garage living space with full architectural drawings — Hampshire Build design

No Planning Usually Needed

Why Convert Your Garage?

Cost-Effective

Much cheaper than building an extension — the structure already exists

No Planning Needed

Most garage conversions fall under Permitted Development rights

Quick Turnaround

Typically completed in 4-6 weeks of construction

Adds Value

A well-designed conversion can add 10-15% to your property value

Types of Garage Conversion

Integral Garage

Built into the main house structure. The easiest to convert as it already shares walls, a roof and often has utility connections nearby. Ideal for a new bedroom, office or family room.

Shares existing walls & roof

Usually no external changes needed

Straightforward building regs

Attached Garage

Connected to the house but with its own roof line. Offers more flexibility for layout and can often be opened up into existing ground-floor rooms to create open-plan living.

Can link into existing rooms

Flexible layout options

Often falls under PD rights

Detached Garage

A standalone structure separate from the house. Can be converted into a self-contained annexe, home office or studio. May require more work on insulation, utilities and access.

Ideal for annexe or office

Complete separation from house

May need planning permission

Planning Permission & Permitted Development

Most garage conversions don't need planning permission, as they fall under Permitted Development (PD) rights. However, there are some important conditions:

Internal conversions with no change to the external appearance generally don't need planning

If you're in a Conservation Area or your home is Listed, you'll need to check restrictions

Detached garage conversions to habitable use may require a planning application

We can apply for a Lawful Development Certificate to confirm PD rights

If your garage was a condition of planning approval, you may need permission to convert

Building Regulations

All garage conversions require Building Regulations approval. This ensures the converted space meets safety and comfort standards:

Structural Integrity — Existing walls and foundations must support habitable use

Insulation & Energy — Walls, floor and roof must meet current thermal standards

Damp Proofing — A proper DPC and moisture barrier are essential

Fire Safety — Fire detection, escape routes and fire-resistant construction

Ventilation — Adequate natural and mechanical ventilation required

Drainage — Floor level changes and drainage solutions for the old garage opening

Garage Conversion Costs

Garage conversions are significantly cheaper than extensions because the main structure already exists. Here's a guide to typical costs in Hampshire:

Single Garage

~15m²

£10,000 – £20,000

Basic conversion to habitable room

Double Garage

~30m²

£15,000 – £30,000

Larger space, more layout options

With En-Suite / Kitchen

Varies

£20,000 – £40,000+

Additional plumbing & fittings

Our design fees start from £1,195 + VAT and include measured survey, architectural drawings and building regulations drawings. See our packages page for full details.

Our Process

Free Consultation

We discuss your ideas, assess feasibility and advise on PD rights or planning needs

Measured Survey

We visit your property to take accurate measurements of the existing garage

Design & Drawings

Architectural plans and building regulations drawings prepared for approval

Build Support

We submit to Building Control and support you through to construction

Frequently Asked Questions

A garage conversion in Hampshire typically costs £15,000–£30,000 to build, depending on size and intended use. Our design packages start from £1,350+VAT. Garage conversions often represent the best value way to add living space without extending your home's footprint.

Most garage conversions fall under Permitted Development rights, meaning no planning permission is needed. However, if you change the external appearance significantly or live in a conservation area, planning permission may be required. We check this during your consultation.

Yes. A well-designed garage conversion typically adds 10–15% to your property value. A single garage conversion can add £20,000–£50,000 depending on your area and the quality of conversion. It is one of the most cost-effective home improvements available.

Popular garage conversions include home offices, playrooms, extra bedrooms, utility rooms, annexes for elderly relatives, and home gyms. The key is ensuring proper insulation, damp-proofing, and natural light. We design conversions tailored to your family's needs.

Yes. All garage conversions require building regulations approval regardless of whether planning permission is needed. This covers structural integrity, insulation, ventilation, fire safety, and damp-proofing. Our Pre-Build Package includes all necessary building regulations drawings.