Buying and selling
Buying a house with subsidence
Yes, a house that has been underpinned can be a sound buy, if the cause was fixed and a chartered engineer designed, supervised and signed off the work. In Census 2022, 28.5% of Irish homes were built before 1971, the age when clay drains and subsidence are most common.
What you're really buying is the paperwork. Get your own engineer to read the report and sign-off from the engineer who supervised the underpinning, and have the drains surveyed before you sign contracts.
Free, no obligation. One local contractor talks it through, not five.
Should I buy a house that has been underpinned?
Often, yes. A house underpinned properly, with the cause dealt with, has had its problem fixed. The house to worry about is the one with fresh cracks and no explanation, or underpinning with no engineer's name on it.
- Underpinned, signed off, cause fixed: ask for the paperwork and have your engineer review it.
- Underpinned, no paperwork: treat it as unknown. Your engineer may need to open up and investigate.
- Cracks now, never investigated: get a structural engineer and a drain survey before contracts, not after.
- The structural engineer's report on the damage and its cause
- The engineer's design for the underpinning (method, depth, extent)
- The engineer's inspections during the work and the final sign-off
- The drain survey, and proof of any new drains and their test
- Invoices, with VAT shown
- Any insurer's letters, if the work was an insurance claim
A buyer's bank will want to see the reports and the costs. An engineer's or architect's sign-off is essential if you want to sell the house on later.
Is a standard house survey enough?
No, not for a house with cracks or a history of movement. The usual pre-purchase survey (a T2) is a visual inspection that doesn't open up the hidden parts of the building. A T3 goes further and is the one to ask for when an issue is suspected. Add a CCTV survey of the drains, and a chartered structural engineer for the cracks.
Which houses are most likely to have had subsidence?
Houses in estates built before the 1980s, before uPVC drains were used. Their sewers are short clay pipes pushed together with no rubber seal, and a leak at one joint washes the ground away under the foundations. See leaking drains and subsidence, and the age of the houses in each county on underpinning by county.
Will I get house insurance on it?
Ask before you sign. Policies can refuse subsidence cover on a building that had subsidence, heave or landslip before, unless that was disclosed to the insurer and accepted. Tell the insurer about the underpinning, send them the engineer's sign-off, and get the quote in writing. See subsidence insurance.
What if I buy without checking?
Then the problem is yours. Damage that started before your policy is excluded, so an insurer is unlikely to pay for it, and the repair comes out of your pocket. See our price guide for what the work costs.
Selling a house that was underpinned?
Gather the same paperwork before you go on the market: report, design, inspections, sign-off, drain survey and invoices. A buyer's engineer will ask for it, and a complete file keeps the sale moving.
Start with a chartered structural engineer. Nobody can tell from a photo or a phone call whether a house needs underpinning. An engineer looks at the cracks, the ground and the drains, then decides. This site never tells anyone their house is safe or unsafe.
FAQ
Questions people ask
Is it a bad thing that a house has been underpinned?
Not if the cause was fixed and an engineer designed and signed off the work. A properly underpinned house has had its problem dealt with. Underpinning with no paperwork is the risk.
Will the bank give me a mortgage on an underpinned house?
The bank will want the engineer's reports and the costs. Have them ready, along with your own engineer's view, before the valuation.
Can I get a survey that checks the foundations?
A standard T2 survey is visual only. Ask for a T3, which goes further, plus a structural engineer and a CCTV drain survey when there are cracks or a history of movement.
Do I have to tell my insurer the house was underpinned?
Yes. Policies can refuse subsidence cover if the building had it before and that wasn't disclosed and accepted.
Who's right?
Only an engineer can say, from the pattern and location of the cracks and whether they're still moving. Get one before contracts, not after.
Who will ring me?
We pass your request to one experienced groundworks and underpinning contractor who covers your county. Your number isn't sent to a list. They ring you, ask what's happening and about any engineer's report, and price the work from the engineer's design. Nothing is booked until you say yes.
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Cracks in the house? Talk it through
Four taps and your number. One experienced groundworks and underpinning contractor who covers your county rings you. Nothing is booked until you say yes.