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See what your garage conversion could cost in 2026, priced by what the room will be used for, with Dublin and rest of Ireland rates. Includes VAT, fees and a contingency.
A garage is a fairly fixed size, so what the room becomes changes the price far more than the floor area does. Plumbing for an ensuite or a kitchen is what pushes the cost up. These are the build costs the calculator uses for a single attached garage, including labour, materials and VAT at 13.5%.
A double garage costs about 1.6 times a single, not twice as much, because the floor, damp-proofing and roof work don't fully double. A detached garage adds €3,000 to €8,000 to run water, drainage and electrics from the house.
| Conversion | Dublin | Rest of Ireland | Double garage, Dublin |
|---|---|---|---|
| Home office or studio | €18,000 to €26,000 | €15,000 to €22,000 | €28,800 to €41,600 |
| Bedroom or living room | €22,000 to €32,000 | €19,000 to €27,000 | €35,200 to €51,200 |
| Bedroom with ensuite | €28,000 to €42,000 | €24,000 to €36,000 | €44,800 to €67,200 |
| Self-contained annex | €42,000 to €65,000 | €36,000 to €55,000 | €67,200 to €104,000 |
Build cost including VAT. Engineer fees and contingency come on top.
Every estimate includes raising or replacing the floor slab. Most garages sit below the house’s damp proof course, so this is one of the biggest and most consistent costs, about 20% of the build. The calculator builds it in rather than treating it as an extra.
The items below only count when they apply to your project, so you can see what moves the number.
| Item | Cost |
|---|---|
| Add a kitchenette | €4,000 to €9,000 |
| Bi-fold or sliding doors instead of a standard wall and window | €3,000 to €7,000 |
| Additional glazing or rooflight | €1,500 to €4,000 |
| Underfloor heating | €1,500 to €3,500 |
| Running services to a detached garage | €3,000 to €8,000 |
| Planning, drawings and professional fees, if needed | €1,500 to €3,000 |
| Engineer and compliance fees | 3 to 6% of the build cost |
| Contingency | 8 to 12% (12 to 18% for an annex) |
Including VAT. A self-contained annex already includes a kitchen, so the kitchenette add-on doesn’t apply to it.
Three common garage conversions run through the calculator. These are Build Me estimates to show how the numbers add up, not prices from finished jobs.
Single attached garage, home office with a rooflight, exempt from planning.
Total budget
€22,000 to €35,000
Double attached garage, bedroom with ensuite and underfloor heating, exempt from planning.
Total budget
€51,000 to €83,000
Detached garage, self-contained annex with kitchen and bathroom, planning needed.
Total budget
€46,000 to €81,000
Optional extras the calculator can add: a kitchenette (€4,000 to €9,000), bi-fold or sliding doors (€3,000 to €7,000), extra glazing or a rooflight (€1,500 to €4,000), underfloor heating (€1,500 to €3,500) and planning with drawings (€1,500 to €3,000).
Converting an attached garage at the side or rear of the house into living space falls under Class 1 of the 2026 exempted development regulations, so it is usually exempt. It counts towards the 45 m² limit for all extensions built on the house since 1964, and the other Class 1 conditions apply, including keeping at least 25 m² of garden.
Replacing the garage door with a wall and window changes the front of the house, and councils sometimes decide that needs permission. A detached garage falls outside Class 1, so living accommodation in one usually needs planning permission. A Section 5 declaration from the council (€80, normally decided within 4 weeks) confirms whether your conversion is exempt. Building Regulations apply either way. Our garage conversion planning guide covers every rule.
It starts from the build cost for what the room will be used for, in Dublin or the rest of Ireland, for a single attached garage. A double garage multiplies that by 1.6, and a detached garage adds the cost of running services from the house.
Engineer and compliance fees are added at 3 to 6% of the build cost. Add-ons and planning only count when you switch them on. The contingency is 8 to 12% of the build, add-ons and planning, or 12 to 18% for a self-contained annex, which has more plumbing and more to go wrong.
An online estimate gets your budget right. A visit gets the price right, because the details that change a price only show up on site.
Use the calculator to set a realistic budget before you speak to anyone.
We visit, look at the house and talk through what you want.
A detailed quote in writing, with materials and every trade listed.
Managed by one team from start to finish.
Still have questions about your garage conversion? Call 01 270 9764 and we’ll be happy to help.
It gives a realistic budget range from current Irish rates and your answers, not a fixed price. The state of the floor, walls and drains only shows up on site, so a written quote after a visit to your home is the only accurate figure for your project.
Roughly €1,200 to €1,800 per m² in Dublin, including VAT. Because a garage is a fairly fixed size, the calculator prices by what the room will be used for rather than by the m², which gives a more reliable figure.
Turning a single attached garage into a bedroom or living room costs about €22,000 to €32,000 to build in Dublin, or €19,000 to €27,000 in the rest of Ireland, including VAT. With engineer fees and a contingency, budget about €24,000 to €38,000 in Dublin. Adding an ensuite brings the build cost to €28,000 to €42,000 in Dublin.
Garage footprints are fairly fixed, so floor area doesn’t vary much between projects. What changes the cost is whether plumbing, a kitchen or an ensuite is involved, which is why the calculator prices by purpose first.
Most garages sit below the house’s damp proof course, so the floor slab usually has to be raised or replaced to meet Building Regulations. It is one of the most consistent costs in a garage conversion, so it is built into the base estimate rather than added later as a surprise.
About 1.6 times a single garage, not twice as much, because the floor preparation, damp-proofing and roof work don’t fully double. A double garage turned into a bedroom or living room in Dublin has a build cost of about €35,200 to €51,200, including VAT.
Often, yes. A detached garage needs water, drainage and electrics run from the main house, which adds about €3,000 to €8,000. Living accommodation in a detached garage also usually needs planning permission, because Class 1 only covers garages attached to the side or rear of the house.
About 6 to 8 weeks on site for an office or bedroom, and 8 to 10 weeks when you add a shower room or kitchenette.