Selling a House with Subsidence: Disclosure, Value, and Your Options

Subsidence is one of the most feared words in UK property. It conjures images of cracking walls, collapsing foundations, and properties that nobody will buy. The reality is more nuanced. Whether you can sell — and for how much — depends critically on whether the subsidence is active or historic, and whether it has been properly investigated and remediated.

Your Legal Disclosure Obligations

Sellers of residential property in England and Wales must complete the TA6 Property Information Form as part of the conveyancing process. This form asks specifically about structural issues, including subsidence.

The question is unambiguous: you must disclose any known movement, settlement, or subsidence affecting the property. This includes:

• Any insurance claims made for subsidence, whether settled or outstanding
• Any structural engineer's reports or investigations carried out
• Any underpinning work carried out at any time in the property's history
• Any monitoring that has taken place (crack gauges, level surveys)
• Any drainage investigations related to subsidence concerns

Failure to disclose known subsidence — or providing misleading information — amounts to misrepresentation under the Misrepresentation Act 1967. A buyer who subsequently discovers undisclosed subsidence can pursue you for damages and, in some cases, rescind the contract. This is a real and significant legal risk.

Active vs. Historic Subsidence: The Crucial Distinction

The single most important factor in how subsidence affects your sale is whether it is active or historic.

Active Subsidence

Active subsidence means the ground movement is ongoing. Cracks are widening, levels are changing, and the underlying cause has not been resolved. This is the most serious position for a seller because:

• Most mortgage lenders will not lend on a property with active, unresolved subsidence
• Buildings insurance may be suspended or restricted during active investigations
• Structural engineers cannot certify the property as stable
• Buyers are limited effectively to cash purchasers or those who can obtain specialist cover

If your property has active subsidence, the realistic sale routes narrow significantly. Cash buyers who can absorb the risk and the remediation cost are the most likely purchasers — and the discount will be substantial.

Historic Subsidence

Historic subsidence is where movement occurred in the past, the cause was identified and addressed, remediation was carried out (typically underpinning or drainage repair), and the property has been monitored and confirmed stable. This is a manageable position for sellers.

Properties with confirmed historic subsidence can be mortgaged — provided the right documentation is in place and a lender is willing to consider. The value discount is real but typically more modest.

The distinction between active and historic is established through a structural engineer's investigation and monitoring programme, typically involving:

• Crack monitoring over a period of time (often 12-24 months)
• Level surveys
• Investigation of the underlying cause (most commonly tree root activity or leaking drains)
• Remediation (underpinning, drain repair, tree removal)
• A follow-up monitoring period to confirm stability

The Certificate of Structural Adequacy

The Certificate of Structural Adequacy (CSA) is one of the most valuable documents a seller can hold when subsidence is in the history.

A CSA is issued by a structural engineer following a completed subsidence investigation and remediation programme. It confirms that:

• The cause of movement has been identified
• The appropriate remediation has been carried out
• The property has been monitored and is now stable
• The structure is considered adequate for its intended use

The CSA is issued on behalf of the insurer who funded the investigation and remediation, and it is typically required by any subsequent lender considering a mortgage on the property.

If you have a CSA, use it prominently. It is the primary evidence that buyers and their lenders need to assess the property confidently. Keep all supporting documentation — structural engineer reports, monitoring data, contractor certificates, and the CSA itself — in a folder ready to share with buyers' solicitors.

If your subsidence was remediated under a buildings insurance claim, your insurer may be able to provide a copy of the CSA if you cannot locate the original.

Value Impact: What to Expect

Subsidence has a measurable negative impact on property value. The extent depends on the subsidence status:

Fully Remediated Historic Subsidence (CSA in Place)

This is the best-case scenario for a seller. A property with a CSA demonstrating successful remediation and confirmed stability typically sells at a discount of approximately 10-15% below comparable properties without subsidence history.

This discount reflects residual buyer hesitation and the narrowed pool of buyers (not all lenders will consider, even with a CSA), but it is manageable. Well-priced, well-documented properties with historic subsidence do sell through estate agents.

Historic Subsidence Without Full Documentation

Where subsidence has occurred but the documentation is incomplete — no CSA, no structural engineer's report, or an incomplete investigation — the discount increases and the buyer pool narrows further. Buyers and their lenders have no basis for confidence, so the discount reflects uncertainty rather than just stigma.

Active or Unresolved Subsidence

An active subsidence situation — or one where an investigation has been started but not completed — typically commands a discount of 25-40% or more, reflecting both the cost of remediation and the risk premium buyers demand for taking on an unresolved structural problem. In some cases, only cash buyers will engage.

Getting a Structural Engineer Report Before Selling

If you are aware of subsidence but do not have a current structural engineer's report, it may be worth commissioning one before marketing the property. The benefits are:

• You control the narrative. A report you have commissioned, reviewed, and can explain is better than a buyer's surveyor raising the alarm mid-transaction.
• You can answer buyer questions with evidence. "Here is the structural engineer's report confirming the subsidence is historic and stable" is a much stronger position than "we had some cracks years ago."
• You reduce the risk of transaction failure. Buyers who are surprised by subsidence partway through a purchase often walk away. Buyers who know from the outset and have been shown the evidence are more likely to proceed.

A structural engineer's report costs approximately £500-1,500 for an assessment of a residential property. If the conclusion is favourable, this is money well spent.

The Insurance Position

Buildings insurance for a property with subsidence history requires careful handling.

Your Current Insurer

If your insurer has funded a subsidence investigation and remediation, they will typically want to retain the policy at renewal. Switching insurers after a subsidence claim can be difficult — new insurers may exclude subsidence or apply very high premiums.

Transferring Insurance to the Buyer

In some cases, sellers can facilitate a transfer of the existing buildings insurance policy to the buyer. This can be valuable because the existing insurer already has full knowledge of the history and has priced it in. A new insurer may decline cover or apply punitive terms.

Discuss with your insurer whether this transfer is possible and what the process would be. Some insurers will agree; others will not.

Buyers' Insurance Position

Buyers of a subsidence-affected property will need to arrange buildings insurance. They need to disclose the subsidence history to any insurer — failure to do so invalidates the policy. This can make insurance expensive or difficult to arrange, which in turn can make the mortgage harder. If you can facilitate an insurance transfer or provide contact details for an insurer familiar with the property's history, this can be a genuine selling point.

Selling with Active Subsidence: Managing the Process

If your subsidence is active and unresolved, the realistic approach is:

1. Get a structural engineer assessment first. Understand what you are dealing with — the cause, the likely remediation, and the cost. This allows you to price the property appropriately and answer buyers' questions.

2. Consider whether to remediate before selling. If the remediation cost is manageable relative to the value impact of selling unremediated, it may be worth completing the remediation first. A property sold as remediated will achieve a better price and a wider buyer pool than one sold as requiring remediation.

3. Price to reflect the discount. Buyers who take on unresolved subsidence are taking on risk. They will price that risk in. Attempting to price as if the subsidence were resolved — and hoping buyers do not notice — creates false hope and wasted time.

4. Target cash buyers. Buyers who do not need a mortgage can take a view on structural risk that mortgaged buyers cannot. Cash buyer companies, individual investors, and developers are all potential purchasers for properties with active subsidence. Our selling route comparison tool can help you model net proceeds from a cash sale versus auction so you can weigh the trade-offs.

5. Consider auction. Traditional property auction can achieve a sale where subsidence has made the open market difficult. Specialist and general property auctioneers have experience marketing subsidence-affected properties to investors and developers. See our guide to selling at auction for more detail.

What Mortgage Lenders Need to See

For buyers who want to use a mortgage to purchase your property, their lenders will typically require:

• The full structural engineer investigation report — documenting the cause, the investigation methodology, and the findings
• Evidence of remediation — contractor certificates, completion certificates for any underpinning, drain repair records
• The Certificate of Structural Adequacy — where one has been issued
• Monitoring data — evidence of continued stability after remediation, typically through crack monitoring and level surveys
• Buildings insurance confirmation — evidence that the property can be insured

Without this documentation, most lenders will not proceed. With it, a number of mainstream and specialist lenders will consider — though the pool is narrower than for a property without subsidence history.

Some lenders specialise in non-standard and problematic properties and are more comfortable with subsidence histories. A specialist mortgage broker can identify which lenders are likely to consider and what documentation they specifically require.

Practical Tips for Sellers

• Gather all documentation before marketing. Structural engineer reports, CSA, monitoring data, insurance correspondence — have it all in one place before you begin.
• Be proactive in sharing it. Provide documentation to interested buyers early, rather than waiting for it to surface in surveys or solicitor enquiries.
• Instruct a solicitor experienced in problematic properties. Not every residential conveyancer is experienced in handling subsidence documentation and the associated lender requirements.
• Set a realistic price from the outset. Overpricing and then reducing creates a poor market perception. Pricing correctly from day one attracts the right buyers and reduces time on market.
• Consider an RICS homebuyer's report or building survey before marketing. Commissioning your own independent survey tells you what buyers' surveyors will find and allows you to manage the information proactively.

This is educational content, not financial advice. Your situation is unique — speak to a qualified structural engineer and mortgage broker before making any decisions.