A garage conversion turns an integral or attached garage into a warm, habitable room by insulating the floor, walls and ceiling, replacing the garage door with a wall and window, and adding heating, lighting and finishes.
Whatever type of house you own in Portsmouth, we start by looking at how a garage conversion would fit it rather than offering a standard package. We cover PO1, PO2, PO3 and PO4 and neighbouring places such as Southsea, Gosport and Fareham. One named person looks after you from survey to handover, and nothing is booked until you hold our figure in writing, fixed for the work described.
- Guide price
- £13,500–£31,500 inc VAT
- Time on site
- 2–6 weeks on site
- Postcodes
- PO1, PO2, PO3, PO4 and PO5
- Planning rules
- England
- Local area
- Hampshire
- Survey
- Free, with a written quote
How much does a garage conversion cost in Portsmouth?
In Portsmouth, guide figures for a garage conversion sit at £13,500–£31,500, VAT included. We set them using rates for the South East, currently about 12% above the national guide. The table shows what pushes a project towards either end of the range; your own price is set after a free survey.
| Type of job | What it usually involves | Guide in Portsmouth |
|---|---|---|
| Integral single garage | A garage within the house footprint, with sound walls and a roof already in place. | £11,000–£20,000 |
| Attached single garage | A garage beside the house that may need roof, wall or floor upgrades. | £15,500–£28,000 |
| Double or detached garage | A larger or separate building, often with a shower room or kitchenette. | £24,500–£50,000 |
What moves the price up or down:
- Garage type: integral, attached or detached
- Condition of the floor, walls, roof and foundations
- Heating method and ventilation for the new room
- Window and door choices and the level of finishes
What does the job include in Portsmouth?
- Infilling the garage door opening with insulated wall and new window
- Foundation checks under the door opening and footings where needed
- Damp-proof membrane, insulated floor and screed or raised timber floor
- New internal door or opening into the house
- Electrics, heating and ventilation by qualified trades, with certificates
- Building control inspections and completion certificate
Homes in Hampshire
Southampton and Portsmouth have dense Victorian terraces, with plenty of post-war rebuilding after wartime bombing. Winchester keeps Georgian and medieval streets, Basingstoke expanded rapidly with 1960s and 1970s estates, and New Forest villages feature cob, thatch and brick. Brick and flint is common on the chalk downs, and new estates ring most towns.
Coastal areas along the Solent face salt and wind, while chalk downland is better drained but exposed; inland clay can move in dry summers.
That mix of housing shapes how we approach a garage conversion in Portsmouth: the age and construction of your home affect the materials, the method and, in the end, the price.
Planning and building rules in Portsmouth
Homes in Portsmouth come under the regulations for England, summarised below. We don't rely on general rules alone: we confirm the position for your address with the council before a quote goes out.
In England, converting an attached or integral garage into a room usually needs no planning permission, unless a planning condition on your estate has removed permitted development rights (common on newer houses). Changing the garage door to a wall and window is generally fine.
Building Regulations approval is needed: foundations for the infill wall, a damp-proof course, insulation, ventilation and fire safety.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
Free site survey
Book a visit and we'll come to you. The survey covers measurements, the state of what's there now and any obvious constraints, so the price that follows is based on your actual home, not an average.
Your fixed price
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
Plan and prepare
We handle the paperwork side: checking whether planning permission or building control approval is needed, submitting applications where they are, and scheduling the trades and materials around your dates.
Finish and handover
Work goes ahead as scheduled and you deal with one contact throughout. When the last trade leaves, we clear and clean the site, talk you through what has been done and pass on any certificates and care instructions.
How we work
Questions about a garage conversion in Portsmouth
How much does a garage conversion cost?
A typical single garage conversion costs £13,500–£31,500, depending on whether the garage is integral, attached or detached and what the room is for. Integral garages usually cost least because the walls and roof are already sound. Adding a shower room, upgrading a flat roof or levelling a sloping floor adds cost. As a guide, allow roughly £550–£1,100 per square metre plus fixed costs. We confirm a fixed price after the survey.
Which postcodes in Portsmouth do you cover?
We cover PO1, PO2, PO3 and PO4, along with the rest of Hampshire. If your postcode is not listed, get in touch anyway: our coverage is UK-wide, and we can usually arrange a survey wherever you live. Enter your postcode in the guide-price tool or contact form and we will confirm.
Will losing the garage affect parking?
Losing a garage can matter if your street has parking pressure or your property deeds or planning conditions require off-street parking. Many garages are too narrow for modern cars, so in practice the driveway often provides the parking anyway. We check for planning conditions affecting the garage before quoting. If you need extra parking, we can also price a driveway extension.
Who do I deal with during the job?
One point of contact manages your project from survey to handover. They schedule the trades working under our contract, keep you updated on progress, and are the person to call with any question. You don't need to coordinate builders, electricians or decorators separately, because that is part of what we do.
Will the new room be warm enough?
A converted garage can be as warm as any other room in the house, provided the floor, walls and ceiling are insulated to current standards. Garages are usually built with single-skin walls and no insulation, so this work matters. Heating can come from a new radiator on your existing system, underfloor heating or an electric heater, depending on your boiler capacity. We advise on the most suitable option.
Also covering areas around Portsmouth
Addresses in PO1, PO2, PO3 and PO4 are all covered for Portsmouth, along with Southsea, Gosport and Fareham close by. Give us your postcode when you get in touch and we will confirm the details.