Surveyor examining cavity wall insulation evidence

Most CIGA 25-year cavity wall insulation guarantees transfer automatically to the new owner when a property changes hands, with no fee and no re-registration. What matters is proving it: sellers should confirm the guarantee is registered and hand a copy of the certificate to the buyer’s solicitor during conveyancing. The main exceptions are installations that were never registered with CIGA, guarantees that have already expired, or insulation that has since been altered or removed.

TL;DR:

A CIGA 25-year guarantee automatically transfers to new owners if the insulation was registered and remains within its valid period.

If the guarantee has expired, the insulation was never registered, or has been altered or removed, transfer is invalid, and cover may be void.

Sellers should verify the guarantee’s status before marketing the property by checking CIGA’s records and obtaining duplicate certificates if needed.

Visible signs of damp or cold patches near insulated walls require independent assessment and should not automatically be attributed to insulation issues.

Independent surveys and clearance certificates are essential for confirming insulation condition and expediting conveyancing.

What the CIGA 25-year guarantee is and what it covers
Does the guarantee transfer when the property is sold?
How to check whether a guarantee exists and what to do if it is missing
What conveyancers, buyers and mortgage lenders expect
How to make a guarantee claim and when extraction may be covered
Common red flags and how they affect a sale
OSCAR Onsite technical guidance on surveys and clearance certification
Seller checklist: preparing your documentation before you list
Why verified guarantees matter to a property sale
Get your documentation and evidence sorted before you list
Sources

What the CIGA 25-year guarantee is and what it covers

The Cavity Insulation Guarantee Agency (CIGA) provides an insurance-backed guarantee lasting 25 years from the date of installation for qualifying cavity wall insulation work. It is not a workmanship promise from the installer alone. It sits behind the installer, backed by insurance, so a claim can still proceed even if the original contractor has gone out of business.

The guarantee covers defects in materials or workmanship inside the cavity, such as insulation that has been installed incorrectly or has failed due to a faulty product. It does not cover damp or condensation caused by unrelated building defects, and CIGA publishes a maximum rectification value, commonly cited as £20,000, above which the guarantee no longer applies.

A few points catch sellers out repeatedly:

The guarantee is tied to the property, not a named individual: CIGA now issues guarantees to ‘The Occupier’ rather than a specific person, a change made partly for data protection reasons.
Cover applies only to the original insulation as installed; if it has been disturbed, extracted, or replaced without re-registration, the original guarantee may no longer apply.
The rectification cap is a ceiling, not a guaranteed payout. It limits CIGA’s liability rather than promising that figure for every claim.

Does the guarantee transfer when the property is sold?

For a CIGA-registered installation still within its 25-year term, the guarantee transfers automatically to the new owner on sale. There is no transfer fee, no form to submit to CIGA, and no re-registration step required by the seller or buyer. This is one of the more useful features of the scheme: unlike some appliance warranties, ownership of the guarantee simply follows the property.

That automatic transfer has limits worth knowing before you assume it applies.

Non-registered installations: if the original installer never submitted the job to CIGA (or used a different guarantee provider), there is nothing to transfer. Some installations under schemes such as the Energy Company Obligation carry their own appropriate guarantees, and the installer is the first point of contact if that work is still recent.
Expired guarantees: a 25-year term run out before the sale means there is no active cover to pass on, whatever the paperwork says.
Altered or disturbed insulation: any extraction, partial removal, or unauthorised interference with the cavity can invalidate cover, even within the 25-year window.

A common misunderstanding is that a missing certificate means no guarantee exists. CIGA holds its own central records and can search for a registered guarantee even when the homeowner cannot produce the original document, though supplying a copy where possible speeds up any conveyancing enquiry considerably.

How to check whether a guarantee exists and what to do if it is missing

Before marketing a property with cavity wall insulation, confirm the guarantee’s status rather than assuming it. The process is straightforward, but each step needs the right paperwork ready.

Search CIGA’s records. Contact CIGA with the property’s postcode and address details to check whether an installation is registered against that address.
Request a duplicate certificate if none can be found. CIGA can issue a duplicate guarantee document for a £60.00 administrative charge (inclusive of VAT), but you must provide formal proof of property ownership, such as a Land Registry document or recent conveyancing paperwork.
Build a supporting file for the legal pack. Gather the installer’s name and contact details, any Energy Performance Certificate references relevant to the insulation, and copies of past survey or repair invoices.

Pro Tip: Order the duplicate certificate as soon as you decide to sell, not once an offer is accepted. CIGA’s identity checks can take longer than sellers expect, and solicitors often stall exchange while waiting for guarantee evidence to arrive.

What conveyancers, buyers and mortgage lenders expect

Cavity wall insulation has to be disclosed on the TA6 Property Information Form, and most buyers’ solicitors will ask for a copy of the guarantee as standard practice once that box is ticked. Skipping this disclosure, or being vague about it, tends to generate more questions later, not fewer.

Surveyors and lenders are alert to specific signals: patches of damp, cold spots on internal walls, or an EPC that flags cavity insulation without supporting evidence of a valid guarantee. A verified, in-date certificate reassures a lender’s valuer that any historic insulation work was registered and covered, which can prevent a mortgage offer being delayed or made conditional.

Timing matters more than most sellers realise:

Instruct your solicitor with the guarantee certificate before the property goes to market, not after an offer arrives.
Flag any known repair history upfront. Buyers’ surveyors are more forgiving of disclosed, resolved issues than problems they uncover themselves.
Keep a digital copy alongside the physical certificate. Solicitors increasingly want a PDF for the legal pack rather than a scanned photograph.

How to make a guarantee claim and when extraction may be covered

A guarantee claim follows a fairly fixed sequence, and skipping steps usually slows things down rather than speeding them up.

Contact the original installer first. Government consumer guidance recommends this as the starting point for defects arising from cavity wall insulation, since many issues are resolved directly without needing to invoke the guarantee at all.
Allow the installer a reasonable chance to investigate and repair. If the installer cannot be traced or the work remains unresolved, escalate to CIGA as the guarantee provider.
CIGA inspects and decides. An inspector assesses whether the defect falls within scope before authorising remedial work.

Typical remedies range from localised remedial plastering and making good, through to full extraction of the insulation in more serious cases. Any payout sits under the rectification cap CIGA publishes, cited by industry sources at £20,000, which covers the cost of rectification rather than wider consequential damage to the property.

Before extraction is agreed, an independent survey report demonstrating that the cavity insulation, rather than another building defect, is causing the damp or cold patches carries real weight with both the guarantee provider and any buyer’s solicitor reviewing the claim history.

Common red flags and how they affect a sale

Surveyors look for a specific set of warning signs when cavity wall insulation is present, and any one of them can prompt further enquiries before a sale proceeds.

Persistent penetrating damp on internal walls, particularly patches that worsen after heavy rain.
Visible mould growth in corners or behind furniture pushed against external walls.
Noticeably cold patches on walls that should be insulated evenly.
Signs of unauthorised drilling or cavity breach from previous, undocumented work.

Any of these can delay exchange, prompt a reduced offer, or push a buyer to insist on remedial work as a condition of completion. None of them confirm the insulation itself is the cause on their own; damp has several possible sources, and only a proper inspection distinguishes them.

Pro Tip: If a buyer’s survey flags damp near an insulated wall, resist the temptation to guess the cause. Commission an independent risk check before agreeing any price reduction; it often costs far less than the discount a nervous buyer will otherwise demand.

OSCAR Onsite technical guidance on surveys and clearance certification

Establishing what is actually happening inside a cavity requires more than a visual inspection from outside. A borescope and thermal imaging survey can reveal moisture staining, debris, or wall tie corrosion, and can identify temperature differences across a wall surface. Thermal imaging shows surface temperature patterns; it does not see inside the cavity itself, and any reading needs interpreting alongside borescope evidence and moisture testing rather than read as a standalone diagnosis.

The recommendation to extract insulation should follow evidence, not assumption:

A risk check first, to establish whether visible symptoms warrant further investigation at all.
A full condition survey where the risk check flags genuine concern, combining borescope inspection with moisture readings.
Extraction only once the cause and condition of the insulation have been independently established, rather than jumping straight to removal on the strength of a damp patch.

Evidence gathered through borescope and thermal imaging supports a diagnosis; it does not replace one. Treating survey findings as proof of a single cause, without ruling out other building defects, risks recommending work the property never needed.

After competent remediation, an independent extraction clearance certificate gives conveyancers and lenders documented confirmation that the cavity has been cleared and inspected, separate from the original installer’s own paperwork.

Seller checklist: preparing your documentation before you list

A short, ordered checklist keeps this from becoming a last-minute scramble during conveyancing.

Locate the original CIGA certificate, or order a duplicate if it cannot be found.
Note the installer’s name and contact details, plus any prior survey or repair paperwork.
If damp, mould, or cold spots are visible anywhere near insulated walls, commission a risk check before the property goes to market.
Where a full condition inspection survey is warranted, act on its findings before agreeing a sale price.
If remedial work proves necessary, use a competent contractor and obtain independent post-remediation clearance rather than relying on the installer’s own sign-off.

Pro Tip: Sellers who sort guarantee paperwork before instructing an estate agent tend to move through conveyancing noticeably faster. Solicitors chase missing certificates constantly, and it is almost always the single biggest avoidable delay in cavity insulation sales.

Why verified guarantees matter to a property sale

Why verified guarantees matter to a property sale — overview diagram

A verified, transferable guarantee is one of the few pieces of paperwork in a house sale that genuinely speeds things up rather than slowing them down. Buyers’ solicitors stop chasing, lenders’ valuers stop flagging, and a nervous buyer gets a concrete reason not to negotiate the price down over old insulation work.

Independent evidence matters more than most sellers assume. A condition survey carried out before problems escalate, and a clearance certificate issued after any remedial work, both remove ambiguity that would otherwise sit unresolved between buyer and seller long after completion.

— Alan

Get your documentation and evidence sorted before you list

OSCAR Onsite is the practical route for sellers who need clear, independent evidence rather than a guess about what a damp patch means. A risk check gives you a fast, low-cost first read on whether cavity insulation is genuinely a concern, before you spend money on anything bigger.

Where the risk check flags something worth investigating, a full CWI condition inspection survey combines borescope and thermal imaging evidence into a report your solicitor and the buyer’s surveyor can both work from. And if extraction turns out to be necessary, an extraction and clearance service followed by an independent clearance certificate gives conveyancers documented proof the cavity has been properly cleared and inspected, separate from any original installer’s paperwork. Book a risk check or condition survey now, well before you list, so guarantee and evidence documents are already sitting in the legal pack when your solicitor asks for them.

OSCAR Onsite Checks: CIGA 25 Year Evidence to Avoid Exchange Delays

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