A garage conversion in Ireland costs roughly €15,000–€35,000 (indicative 2026 range), depending mainly on how much insulation, heating and plumbing you add. Because the structure already exists, it’s usually cheaper than building an extension of similar size.
Garage conversion cost by spec
| Spec | What’s involved | Indicative 2026 cost |
|---|---|---|
| Basic habitable room | Insulate, infill the door opening, floor, electrics, heating, plaster, decorate | €15,000–€22,000 |
| Higher spec | Better insulation, larger glazing, integrated heating, quality finishes | €22,000–€30,000 |
| With plumbing | Adding an en-suite, utility or kitchenette | €28,000–€35,000+ |
What’s included
- Infilling the garage door opening with an insulated wall, window or door.
- Floor — insulation, damp-proof membrane and a level finished floor (garage floors are often lower than the house).
- Wall and roof insulation to make the space warm and dry.
- Damp-proofing and ventilation.
- Electrics — new sockets, lighting and circuits.
- Heating — extending the central heating or adding an independent source.
- Plumbing if adding a bathroom or kitchenette.
- Plastering, flooring and decoration.
Insulation and heating: the make-or-break
Garages were never designed as living space, so the comfort of the finished room depends almost entirely on getting the insulation, damp-proofing and heating right. Skimp here and you get a cold, condensation-prone room nobody uses. Budget for proper floor, wall and roof insulation, a damp-proof membrane, trickle ventilation and a genuine heat source — whether that’s extending your existing system or fitting an efficient standalone unit. Doing this well also lifts your home’s overall energy performance; see how to improve your BER rating for the broader picture.
Planning permission
Converting an attached garage to a habitable room within the existing footprint is often exempt from planning permission, but exemptions carry conditions — and altering the front elevation (for example, replacing the garage door with a different finish) can affect that. Detached garages and any change that alters the building’s use or appearance may need permission. Always confirm your specific case with the local authority before you start.
What affects the price
- Plumbing. Adding a bathroom or kitchenette is the biggest cost jump.
- Floor level. If the garage floor is well below the house, raising and insulating it adds work.
- Insulation depth. Higher standards cost more upfront but pay back in comfort and running costs.
- Glazing. Replacing the door with large windows or doors adds cost.
- Heating method. Extending the existing system vs a standalone unit.
- Condition. Damp, cracking or poor existing construction adds remedial work.
Ways to save
- Keep it a single dry room without plumbing if budget is tight.
- Extend existing heating rather than installing a separate system where practical.
- Reuse the existing slab if it’s sound and at a workable level.
- Don’t cut corners on insulation or damp-proofing — fixing a cold, damp conversion later costs far more.
- Get at least three written quotes, each specifying the insulation standard and heating method.
Build in a contingency for damp or level issues, and get the scope — especially the insulation spec — in writing before work begins.