Bedroom and en-suite extensions
A bedroom extension is a new room on the ground floor or upstairs, usually with an en-suite. A 16 m² ground-floor bedroom with an en-suite at a standard finish costs about €32,000 to €45,000 in Galway, including fees and VAT. Upstairs, a bedroom goes on as part of a two-storey extension: 36 m² over two floors, mid-range with an en-suite, is about €96,000 to €118,000 at national rates.
One more bedroom without moving: on the ground floor, upstairs or in the garage, with a shower room of its own.
Free and no obligation. Your plan goes to one builder, not a list.
- 43%of Irish houses have exactly three bedrooms (Census 2022)
- 3.2bedrooms in the average Irish home
- €4,000–€18,000an en-suite, standard to mid-range
- €40,000the most the Housing Adaptation Grant pays
Where the bedroom can go
On the ground floor, at the back
The simplest: part of a single-storey rear extension, usually exempt within 45 m². Right for a parent moving in, or for anyone who will find stairs hard. Pair it with a shower room and it is a small apartment within the house.
Upstairs
Over a new ground-floor room as a two-storey extension. It costs less per m² (€2,000 to €2,500 against €1,500 to €2,200), but upstairs the exemption stops at 12 m² on a semi or terrace, so it usually needs planning permission.
In the garage
€15,000 to €25,000 to convert at a standard finish, and usually exempt. Garage conversions.
The en-suite
Fitting out an en-suite or shower room inside the new extension costs €4,000 to €8,000 with standard fittings and simple tiling, €10,000 to €18,000 mid-range, and €20,000 to €40,000 for a walk-in shower or wet room with premium fittings. The room itself is in the extension's build cost.
Put it on the side of the bedroom nearest the existing soil pipe, or above the downstairs bathroom in a two-storey extension. Every metre of new drain under a floor is digging you pay for.
Plan your house extension
Four quick taps, and your plan fills in as you answer: what it costs, whether it needs planning permission and how long it takes. Contact details come last, and only if you want a builder to price it.
16 m² single-storey rear, mid-range finish, with an en-suite: €45,000 to €63,000, including VAT and fees.
How the estimate is worked out
Every kind of extension has a build rate per m² for each region of Ireland, VAT at 13.5% included. A standard finish uses the lower half of that range and mid-range the upper half; high spec or a wall of glass moves the build to the glazed rate. Design, engineer and BER fees go on top, with anything you tick (an en-suite, a kitchen, a steel beam into the house) priced at your finish. A garage conversion gets one price for the whole job, since the walls and roof are already standing. Totals are rounded to the nearest €1,000. Use it to plan with. It isn't a quote: a builder prices your house after seeing it.
Why families add a bedroom
58% of Irish houses have three bedrooms or fewer, and 43% have exactly three (Census 2022). The average semi-detached house has 3.2 bedrooms and the average terraced house 2.8. A fourth bedroom is the most common reason a family outgrows a house it otherwise likes.
Moving to get one costs stamp duty, agent's and legal fees before the bigger house's higher price. Extend or move house sets the two side by side.
A bedroom for someone with a disability
Councils pay the Housing Adaptation Grant for People with a Disability towards work a disabled person needs, and that can be an extension: a ground-floor bedroom, or a bathroom they can use. The grant is capped at €40,000. A household with gross income of €37,500 or less can have all of the approved cost paid; the share falls as income rises, to 30% between €62,501 and €75,000. Apply, and get approval, before any work starts. The grant on gov.ie.
Every way to extend
Each has its own page: costs by size, the planning rules that apply and the weeks of building.
Single-storey rearOne new room behind the house at ground level: a family room, a playroom or a bedroom for a parent.
Two-storeyTwo new floors in one build: more living space downstairs and an extra bedroom over it.
Side extensionThe strip beside a semi or detached house, built on at one level or two.
WraparoundAn L round the back corner of the house, for one big room with a utility or toilet off it.
Garage conversionThe garage you already have becomes a bedroom, an office or a playroom.Questions before you build
How much does a bedroom extension cost in Ireland?
A bedroom extension is a new room on the ground floor or upstairs, usually with an en-suite. A 16 m² ground-floor bedroom with an en-suite at a standard finish costs about €32,000 to €45,000 in Galway, including fees and VAT. Upstairs, a bedroom goes on as part of a two-storey extension: 36 m² over two floors, mid-range with an en-suite, is about €96,000 to €118,000 at national rates.
How much does an en-suite cost?
€4,000 to €8,000 with standard fittings, €10,000 to €18,000 mid-range and €20,000 to €40,000 high-end, to fit out inside the new room.
Do I need planning permission for a bedroom extension?
Not for a ground-floor bedroom at the back within 45 m² that meets the conditions. Upstairs, the exemption stops at 12 m² on a semi or terrace, so a bedroom over a new room usually needs it.
Is there a grant for a bedroom extension?
Only for a person with a disability: the Housing Adaptation Grant pays up to €40,000 through your council.
Is a ground-floor bedroom a good idea?
For a parent moving in, or anyone who may find stairs hard later, yes. With a shower room it works as a small apartment within the house.
Every guide, calculator and county page
Jump straight to any specification guide, our interactive calculator, the technical glossary or your county page.
Price & Specification Guides
Calculator, FAQ & Glossary
Room to grow, without moving
Pick the type, the size and the finish to see the cost in your county. When you want a firm price, your plan goes to a single vetted builder for your area.