The Ultimate Guide to Garage Conversions in Brighton & Hove
Unlock hidden floor-space, add value and future-proof your coastal home.
Introduction – Why a Garage Conversion Beats an Extension
Brighton & Hove homes are prized for their period façades and tight urban plots. Building outward often means losing garden or falling foul of conservation-area rules. A garage conversion can reclaim 15 – 25 m² of heated, usable space inside the footprint you already own, for roughly half the cost per square metre of a rear extension. When undertaken by a specialist team familiar with bungaroosh walls, salty air and strict local planning, the project offers five stand-out gains:
Rapid delivery – many single conversions complete in six weeks of on-site work.
Minimal red tape – most garages convert under Permitted Development.
No loss of amenity – gardens, side paths and parking bays stay intact.
Energy upgrade – new insulation, triple glazing and airtightness can lift your EPC by one full band.
Market appeal – a dedicated home office, guest suite or gym commands premium resale value in Brighton’s competitive market.
This page covers every stage from first sketch to final sign-off.
Eight deep-dive articles are referenced—each will expand on specialist topics without repeating the information you’re reading here.
Feasibility – Is Your Garage a Good Candidate?
Before ordering drawings, test three fundamentals:
Footprint & Proportions
Most Brighton garages measure 2.4 – 2.6 m wide internally—fine for a single bedroom, office or gym once insulation and plaster reduce width by about 100 mm each side. Depth of 4.5 m allows a micro shower-room plus storage. Double garages (5.5 – 6 m wide) offer luxury layouts.
Structure & Foundation
Early 20th-century garages often sit on shallow footings or even corbel bricks over chalk. A structural engineer checks load paths before you swap the door for a cavity wall and glazing. Bungaroosh walls complicate matters; lime pinning and extra studs may be essential.
Services Routing
Is the consumer unit in the garage? Perfect. If not, budget for a sub-board. Plumbing a WC means dropping a soil pipe to the nearest stack or adding a macerator. High-speed data? Pre-run CAT-6 or fibre beneath the new floor screed.
Permission Pathways – Planning vs Building Control
Brighton & Hove City Council treat garage conversions as change of use within the envelope, so Permitted Development usually applies. You will, however, need a lawful-development certificate to calm future buyers. You’ll definitely lodge a formal householder application if any of these apply:
The façade faces a public road and you plan to replace the door with full-height glazing.
The property is in the Brunswick, Clifton Hill, West Hill, North Laine or Old Town conservation areas.
The garage is curtilage-listed or attached to a listed building.
You intend to widen, lengthen or raise the existing envelope.
Full paperwork guidance lives in Planning Permission for Garage Conversions in Brighton.
Regardless of planning, Building Regulations approval is mandatory. Your inspector will inspect foundations, new beams, fire separation, insulation, electrics and drainage. A line-item compliance checklist appears in Building Regs Checklist for Brighton Garage Conversions.
Structural Works – From Doorway to Living Wall
Removal of the garage door – roller gear is stripped and the lintel exposed.
Goal-post frame installation – steel or glulam uprights plus top-beam, sized by a structural engineer.
Subframe & infill – blockwork cavity wall or heritage sash/glazed screen if the street-scene demands it.
Floor upgrade – damp-proof membrane, insulation, optional under-floor heat and a new screed.
Tie-ins & straps – ensure the new wall ties back to existing masonry; bungaroosh often needs resin anchors.
A week-by-week plan is set out in Garage Conversion Project Plan.
Tackling Bungaroosh – Brighton’s Wildcard Wall Fabric
Victorian coach houses hide bungaroosh walls beneath cement render. Because bungaroosh is lime-rich and porous, modern gypsum or sand-cement traps moisture and creates bulges.
Special considerations:
Strip cement by hand tools; avoid angle-grinders that vibrate the aggregate loose.
Pin large voids with chestnut laths and hot-lime mortar.
Render in three lime coats or leave breathable limewash.
Avoid injected chemical DPCs; treat rising damp with limecrete and capillary drainage.
More depth is provided in Bungaroosh Pitfalls in Garage Conversions.
Moisture, Ventilation & Thermal Comfort
Garages are unheated boxes. Once insulated, they still risk condensation unless you follow three golden rules:
Continuous insulation – avoid breaks at timber plates, steel beams and window reveals.
Airtightness plus controlled ventilation – MVHR or at least humidity-tracking extract stops stale air.
Breathable finishes – lime plaster or a vapour-open primer beneath standard emulsion.
Design strategies feature in Preventing Condensation in Converted Garages.
Heating, Electrics & Plumbing
Heating – oversized radiators on the existing circuit, electric UFH mats under engineered-wood floors, or an air-to-air heat pump for gym spaces.
Electrics – a dedicated ring main protected by RCBOs, LED down-lights, 2 – 4 twin sockets per wall and CAT-6 points.
Plumbing – microbore feeds for en-suite WCs, shower trays set into the new screed and pumped waste where gravity falls short.
Layouts and kit costings live in Heating & Services for Garage Conversions.
Room-Type Inspiration & Design Ideas
Home office / studio – south-facing roof windows, acoustic plasterboard and data trunking.
Self-contained annexe – pocket-door shower-room, kitchenette and built-in wardrobes.
Home gym – rubber floor, 32 A socket for a treadmill and reinforced ply anchorage.
Kids’ playroom – washable clay paint and magnetic whiteboard panels.
Accessible bedroom – level threshold, 900 mm doors and ENSITE gravity-fed wet-room.
Budgeting & Finance
Spring 2025 averages for Brighton & Hove:
Basic single-garage conversion (office spec): £28 000 – £34 000
Mid-spec with en-suite: £38 000 – £45 000
Double garage to annexe: £55 000 – £70 000
Cost drivers:
Bungaroosh remediation and lime render.
New plumbing runs across floor or ceiling voids.
Heritage-matched glazing and brick slips.
Mechanical ventilation with heat recovery.
A full cost spreadsheet appears in Garage Conversion Cost Guide for Brighton Homes.
Bank loans, further-advance mortgages and Brighton & Hove Credit Union all support this scale of project. Adding a functional bedroom can push many properties into a higher valuation band, making lender approval easier.
Typical Timeline
Quote & survey – 1 week
Optional planning / lawful development – 8 weeks
Build phase – 4 – 6 weeks
Dry-out, snagging, Building Control sign-off – 1 week
Delve deeper into this element on the Garage Conversion Timeline. page.
Common Pitfalls to Avoid
Ignoring ventilation – leads to mould within a year.
Using sand-cement on bungaroosh – locks in moisture and causes bulging.
Under-spec insulation – fails Part L and future-proofing.
Skipping a structural engineer – cheap today, expensive if cracks appear later.
Read the full list in Garage Conversion FAQs & Mistakes to Avoid.
After-Care & Maintenance
Test smoke alarms every month; garage ceilings often sit beneath habitable rooms.
Re-lube bifold or slider tracks yearly in Brighton’s salty air.
Limewash external render every five years, or wash silicone render annually.
Check MVHR filters twice a year.
Further Reading
Ready to Reclaim Your Garage?
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