Kitchen extension guides, estimator and reference
Every cost guide, extension type comparison, planning rule, interactive estimator, FAQ and technical glossary on kitchenextension.ie.
Free, no obligation. One local builder prices it, not five.
- 45 m²exempt rear limit
- €1,500–€2,200per m² build cost
- 15glossary terms
- 7county guides
Every kind of kitchen extension
The costs, the rules and what to ask for, a page each.
Single-storey rearAcross the back of the house, usually with roof windows and wide glass to the garden.
Side returnThe narrow passage beside a terrace's back return, filled in and lit from above.
WraparoundAn L round the back and down the side, for one big kitchen, dining and living room.
Two-storeyA bigger kitchen below and a bedroom above, on one set of foundations.
Roof windows and lanternsFlat with roof windows, pitched, or a glazed lantern over the middle of the room.
Bifold or sliding doorsThe back wall opens to the garden. Which opens better, which seals better.Plan your extension and see the cost
Four quick taps. You see your plan build up as you go: the price range, what moves it, the planning position and the build time. Your number is only asked for at the end, if you want a real price.
A 25 m² single-storey rear extension in Ireland, mid-range, with wide glass doors and a new kitchen: €62,000 to €90,000 all in, including VAT and fees.
How this is worked out
We start from what single-storey extensions cost to build per square metre in each part of Ireland, including VAT at 13.5%, and the rates for side, wraparound, two-storey and heavily glazed extensions. Standard finishes take the lower half of the range, mid-range the upper half, and high spec or a wall of glass the glazed rate. Then we add professional fees (design, engineer, BER) and, if you want one, a new kitchen at your level of finish. Totals are rounded to the nearest €1,000. It's an estimate to plan with, never a quote: the builder prices your house after seeing it.
Estimator, FAQ and glossary
| Resource | What's inside | How it helps |
|---|---|---|
| Interactive Extension Estimator | Live price range | Pick your extension type, size, spec and county to see a full cost breakdown. |
| Master FAQ Hub | 21 questions answered | Straight answers on per m² build rates, the 45 m² rule, BCAR, VAT and timelines. |
| Technical & Trade Glossary | 15 terms defined | Plain-English definitions of Irish planning, structural and building control terms. |
| County Cost & Council Guides | 7 county pages | Local extension build rates, CSO housing data and one vetted builder who covers your county. |
Questions people ask
Can I stay living in the house while a rear kitchen extension is being built?
Yes. On most single-storey rear extensions the builder builds the foundations, outer walls, roof and glazing from the garden side for the first 7 to 9 weeks before knocking through the back wall of the house. Temporary dust walls and a working sink/kettle station keep the rest of the home liveable until the new kitchen is fitted.
When should I order my new fitted kitchen and patio doors during an extension build?
Order your rear sliding or bi-fold doors and rooflights as soon as the blockwork shell starts (around Week 3 to 4) because bespoke aluclad and aluminium glazing takes 5 to 8 weeks to manufacture. Finalize your kitchen layout before first-fix electrics and plumbing (Week 7 to 8) so island power ducts, extractor ducts and waste pipes land in the exact millimetre position.
What happens if there is a shared drain pipe running across my back garden?
Nearly every Victorian terrace and 1960s-1990s semi-detached estate has a shared foul or storm drain running parallel to the back wall. Your builder either diverts the pipe around the outside of the new extension with new inspection chambers outside the room, or bridges where the pipe passes through the concrete foundation walls with lintels and rocker pipes and seals it in concrete.
How close to my neighbour's boundary wall can I build a rear kitchen extension?
Structurally you can build right up to the legal boundary line using a parapet wall and internal box gutter so no fascia or gutter overhangs your neighbour's property. Under Class 1 exempted development rules, any window in a side wall facing a boundary must be at least 1 metre back from that boundary.
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
Get a free quote for your extension
Plan it in under a minute, see the cost, and one vetted builder who covers your county rings you with a proper price.