Basement conversion in Sligo
Converting a basement in Sligo costs €1,000 to €2,500 a m², and tanking €50 to €180 a m². Tell us the job and one basement company that covers Sligo, Tubbercurry and Strandhill and the rest of Co. Sligo rings you with a written price.
Free, no obligation. One local company prices it, not five.
- 24.9%of homes the EPA measured in Sligo were above the radon reference level
- 1,341 mmof rain a year at Tubbercurry
- 16%of Sligo homes were built before 1946
- €1,000 to €2,500a m² to convert a basement
Basements and the work



Basements in Sligo
Census 2022 counted 26,801 households in Sligo. 2,196 homes (8%) were built before 1919 and 16% before 1946: the period houses where most cellars and basement storeys are. 56% are detached, with room at the side or back for a light well.
102 one-off houses were finished in Sligo in 2025. A basement costs least when it's designed in before the house is built.
Radon in Sligo
Of the 2,698 homes the EPA has measured in Sligo, 671 (24.9%) were above the 200 Bq/m³ reference level, and 111 were above 800. The highest reading was 5,600 Bq/m³. That's the 1st highest share of the 26 counties, against 14.1% nationally.
That's high. In Sligo, put a radon barrier and a sump into any basement plan from the start, and test the room once it's in use.
Water and Sligo basements
Tubbercurry gets 1,341 mm of rain a year, Sligo 1,253 mm and Strandhill 1,159 mm.
That's wet ground for much of the year. Water pushes against basement walls in Sligo more often than in the east, so a drained membrane with a sump and a back-up pump is the safer system here.
Planning in Sligo
Converting an existing basement inside the house usually needs no permission. A new basement, a new front light well or a protected structure is a question for Sligo County Council. See planning permission.
What it costs for your size
Two taps: the job and roughly how big the basement is. The answer comes from our price guide.
Typical range
€30,000 to €75,000
30 m² at €1,000 to €2,500 a m², the usual range to turn an existing basement into a finished room. Tanking with a membrane and a sump is often priced on top, at €3,000 to €12,000.
Send this for a real priceHow this is worked out
For a conversion or a dig-out, the floor area times our range a m² (€1,000 to €2,500 to convert, €3,000 to €6,000 to dig). For tanking, the typical price for a basement that size. It's a guide, never a quote: the company prices your basement after a look. Building work on a house is charged VAT at 13.5%. Ask whether the written price includes it.
Get a price in 4 taps
Tap what you need and leave your number. It goes to one basement company that covers your county. They ring you back to arrange a look and a written price.
Basement conversion and waterproofing guides & price breakdowns
Straight answers to what people ask most: itemised costs, specifications, planning or grants, and what to check before you book.
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Sligo questions
How much does a basement conversion cost in Sligo?
€1,000 to €2,500 a m² to convert an existing basement, or €30,000 to €100,000 for most. Tanking alone is €50 to €180 a m².
Is radon a problem in Sligo basements?
24.9% of the homes the EPA measured in Sligo were above the reference level. Seal the floor and fit a radon sump while the basement is open.
Do I need planning permission for a basement in Sligo?
Not usually inside an existing basement. A new basement or a protected structure is a question for Sligo County Council.
Do you cover all of Co. Sligo?
Yes. Requests from Sligo, Tubbercurry, Strandhill, Collooney and Ballysadare and everywhere else in Sligo go to one basement company that covers your county.
How long does a basement conversion take in Sligo?
6 to 12 weeks for most. Planning, where it's needed, comes first.
Basement conversion and waterproofing across all 26 counties
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Get a free quote for your basement
One company that covers your county rings you. Nothing is agreed until you accept a written price.
