Basement conversion in Longford

Converting a basement in Longford 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 Longford, Edgeworthstown and Ballymahon and the rest of Co. Longford rings you with a written price.

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11.9%of homes the EPA measured in Longford were above the radon reference level
1,052 mmof rain a year at Edgeworthstown
14%of Longford homes were built before 1946
€1,000 to €2,500a m² to convert a basement

Basements and the work

A white terrace of period town houses with black railings and basement areas along a stone pavement — **Period houses.** Period town houses with basement areas behind the railings

A black and white photo of a dug-out site with concrete formwork, steel and a mini digger — **Digging out.** A site dug out, with formwork and steel in for the foundations

A long curved terrace of white period houses with balconies and black railings along the pavement — **Period houses.** A long terrace of period houses with basement areas behind railings

Basements in Longford

42Longford homes measured above 200 Bq/m³

1,403Longford homes built before 1919

1,052 mmrain a year at Edgeworthstown, the wettest of three Longford towns

77one-off houses finished in Longford in 2025

Census 2022 counted 16,206 households in Longford. 1,403 homes (9%) were built before 1919 and 14% before 1946: the period houses where most cellars and basement storeys are. 63% are detached, with room at the side or back for a light well.

77 one-off houses were finished in Longford in 2025. A basement costs least when it's designed in before the house is built.

Radon in Longford

Of the 354 homes the EPA has measured in Longford, 42 (11.9%) were above the 200 Bq/m³ reference level, and 1 were above 800. The highest reading was 900 Bq/m³. That's the 13th highest share of the 26 counties, against 14.1% nationally.

Plan the floor seal and a radon sump in with the waterproofing in Longford: it costs least while the floor is open.

Water and Longford basements

Edgeworthstown gets 1,052 mm of rain a year, Longford 1,019 mm and Ballymahon 956 mm.

Drier than the west. In Longford it's more often the water table, a leaking drain or a gutter than the rain itself that wets a basement. Find the source before choosing the system.

Planning in Longford

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 Longford 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.

The job

Convert an existing basementInto a finished roomWaterproof (tank) itDamp or water coming inDig a new basementOr lower the floor

Floor area, roughly

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.

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How 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.

Near Longford

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.

Cost & Pricing GuideBasement conversion cost in IrelandBasement conversion cost in Ireland: €1,000 to €2,500 a m², €30,000 to €100,000 for most. Tanking €50 to €180 a m². Our price guide and one free quote.Read the guide →Specification GuideBasement sump pumpsBasement sump pumps in Ireland: €1,000 to €2,000 for a sump system. How a sump works, two pumps, battery back-up, alarms and servicing. One free quote.Read the guide →Comparison GuideTanking vs cavity drain membraneTanking vs cavity drain membrane for a basement in Ireland: how each works, which suits a wet basement, costs, sumps and guarantees. One free quote.Read the guide →Grants & RegulationsBuilding Regulations for a basementBuilding Regulations for a basement in Ireland: escape in a fire (Part B), radon and damp (Part C), ventilation (F), insulation (L), structure (A).Read the guide →Specification GuideRadon and basementsRadon in basements in Ireland: the 200 Bq/m³ reference level, High Radon Areas, radon sumps (€500 to €2,000) and testing. One free quote.Read the guide →Timeline & PreparationHow long a basement conversion takesHow long a basement conversion takes in Ireland: 6 to 12 weeks for most, waterproofing 1 to 2 weeks, finishing 2 to 3 weeks. Digging out takes longer.Read the guide →

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Longford questions

How much does a basement conversion cost in Longford?

€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 Longford basements?

11.9% of the homes the EPA measured in Longford 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 Longford?

Not usually inside an existing basement. A new basement or a protected structure is a question for Longford County Council.

Do you cover all of Co. Longford?

Yes. Requests from Longford, Edgeworthstown, Ballymahon, Drumlish and Granard and everywhere else in Longford go to one basement company that covers your county.

How long does a basement conversion take in Longford?

6 to 12 weeks for most. Planning, where it's needed, comes first.

Basement conversion and waterproofing across all 26 counties

Requests from all 26 counties go to one vetted local specialist who covers your county — from Dublin, Cork, Galway and Limerick to Kildare, Meath, Wicklow, Waterford and Donegal. Pick your county below for local prices, specifications and advice. Compare all areas covered →

Get a free quote for your basement

One company that covers your county rings you. Nothing is agreed until you accept a written price.