Portsmouth · Garage Conversion

Garage Conversion
in Portsmouth

Vetted local garage conversion specialists. Free quotes from FMB & CIOB-qualified builders in Portsmouth. 3 quotes in 24 hours, no obligation.

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Maintained by the BestBuilders Editorial Team
Garage Conversion specialists in Portsmouth verified by our UK editorial team. Credentials, cost data & FAQs reviewed quarterly. Last reviewed . How we research & fact-check
✉ info@bestbuilders.co.uk
Vetted Garage Conversion Specialists
1,200+ Verified Reviews
Minimum £2m Insurance
Free No-Obligation Quotes
Local Portsmouth Experts
110+
Garage Conversion Specialists in Portsmouth
4.5
Average Star Rating
440+
Projects Completed in Portsmouth
£0
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Portsmouth Garage Conversion Prices

How Much Do Garage Conversion Cost in Portsmouth?

Real prices from completed projects in Portsmouth and the surrounding area. Costs vary by size, specification and access — use these as a starting guide, then get 3 free quotes for your specific project.

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Single garage conversion
Standard Single Garage Conversion
£ 9,440 – £21,240

Convert an attached single garage into a habitable room — bedroom, office or playroom. Most fall under permitted development. 6–10 weeks on site.

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Double garage conversion
Full Double Garage Conversion
£ 17,700 – £35,400

Convert a double garage into a self-contained living space, en-suite annexe or large open-plan room. Strong ROI for £15k–£30k.

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Detached garage conversion
Detached Garage Conversion
£ 21,240 – £41,300

Convert a detached or outbuilding garage into an annexe, home office or studio. May require planning permission depending on use.

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Your Project
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Costs depend on size, spec and access. The best way to know your exact price is to compare 3 quotes from vetted local specialists.

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Portsmouth pricing note: Southern England (Hampshire, Dorset, West Sussex) sits around 10–15% above the national average. Coastal locations and areas with restricted site access can attract additional charges from contractors. Prices shown are indicative ranges for Portsmouth and Southern. Always get at least 3 written quotes before committing to any builder.

Why BestBuilders for Garage Conversion in Portsmouth

Garage Conversion Specialists Who Know Portsmouth

Portsmouth is one of the UK's most active home renovation markets. With a diverse range of properties across the area, from period homes to modern new builds, local builders need to be versatile, skilled, and reliable.

BestBuilders vets every builder in our Portsmouth network. We check for public liability insurance, relevant trade qualifications (CIOB, FMB, Gas Safe, NICEIC), and a minimum of five verified customer reviews before any builder can appear on our platform.

Whether you are planning a rear extension, a loft conversion, or a full kitchen renovation in Portsmouth, we will connect you with the right specialist within 24 hours. All quotes are free and there is no obligation to proceed.

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How It Works

1
Tell us your project
Describe your garage conversion project and postcode. Takes 60 seconds.
2
We match you instantly
We send your brief to up to 3 vetted garage conversion specialists in Portsmouth.
3
Compare and choose
Review quotes, profiles and reviews. No obligation to proceed.

Every Builder We Recommend Is:

✓ Minimum £2m public liability insurance — verified before listing
✓ Holds relevant trade qualifications (FMB, CIOB, FMB, CIOB)
✓ Has a minimum of 5 verified customer reviews before joining
✓ Actively monitored — removed for sustained negative feedback
Customer Reviews

What Portsmouth Homeowners Say About Our Garage Conversion Specialists

★★★★★ 4.5 / 5
★★★★★

Converted our integral single garage into a home office last spring. Builders quoted £14k and finished in 7 weeks - exactly as promised. Building regs sign-off was straightforward, no planning needed. Now using it daily as a proper workspace.

James M.
Portsmouth
Garage Conversion
★★★★★

Double garage to annexe for my father-in-law. Total cost £28k including kitchenette and shower room. The builder via BestBuilders sorted everything from drawings to final inspection. Fantastic outcome, would recommend.

Sarah K.
Portsmouth
Garage Conversion
★★★★☆

Converted our garage into a playroom for the kids. Initially worried about damp from the existing slab but our specialist did proper damp-proofing and full insulation upgrade. Came in on budget at £11k. Two minor snags fixed within a week.

David R.
Portsmouth
Garage Conversion
Frequently Asked Questions

Garage Conversion in Portsmouth — FAQs

Builder day rates in Portsmouth typically range from £180 to £380 per day depending on the trade and project type. A single-storey extension typically costs £27,000 to £55,000 in Portsmouth. Get 3 free quotes to compare accurate prices for your specific project.
Many home extensions in Portsmouth fall under Permitted Development rights, meaning planning permission is not required. However, you will need to apply to the local planning authority if your property is listed, in a conservation area, or if the extension exceeds permitted development size limits. Our builders can advise during your free quote.
Through BestBuilders, you will typically receive your first quotes within 24 to 48 hours. Most Portsmouth builders in our network can begin projects within 2 to 8 weeks, depending on the time of year and project size. Summer is the busiest season so booking earlier is advisable.
Yes. Every builder in our Portsmouth network is vetted before joining. We verify public liability insurance (minimum £2m cover), trade qualifications, company registration and a minimum of 5 verified customer reviews. Builders with a sustained pattern of negative feedback are removed from the platform.
Autumn and winter are generally the best times to hire builders in Portsmouth as demand is lower and you may have more flexibility on price and start dates. Spring and summer are peak season with longer waiting times. That said, quality builders in Portsmouth stay busy year-round.
Nearby Areas

Garage Conversion Near Portsmouth

We also connect homeowners with vetted garage conversion specialists in towns surrounding Portsmouth.

Waterlooville Fleet Romsey Southampton Andover Aldershot Lymington Totton Petersfield Gosport Fareham Sandown

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About This Page

Editorial standards & how to reach us

This Garage Conversion in Portsmouth page is maintained by the BestBuilders Editorial Team. Every garage conversion specialist we recommend is verified for insurance (minimum £2m public liability), relevant trade qualifications (FMB, CIOB where applicable), and a minimum of five verified customer reviews before joining our platform. The cost ranges shown are cross-referenced against RICS BCIS regional data and itemised quotes flowing through the BestBuilders platform each month. For a full cost breakdown see our Garage Conversion cost guide. FAQ content is reviewed quarterly.

Spotted something out of date? If a listed garage conversion specialist has moved on, a cost range looks wrong for Portsmouth, or you've had a poor experience with a contractor we recommended — we want to know. Email info@bestbuilders.co.uk or call 0800 852 7782. Every report is investigated and accepted corrections typically go live within 48 hours.

BestBuilders Editorial Team
UK-based · Reviewed 20 April 2026
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