CIGA Guarantee Claims: What Homeowners Should Check Before Making a Claim
If your property has cavity wall insulation covered by a CIGA guarantee and you are experiencing damp, mould, cold areas, condensation or concerns about the condition of the insulation, it can be tempting to assume that the CWI has failed.
But a symptom is not the same as a diagnosis.
Before making significant decisions — and particularly before allowing cavity wall insulation to be extracted or substantially disturbed — OSCAR Onsite recommends establishing the history of the installation, gathering the available documentation and obtaining evidence of the current condition of the cavity and insulation.
INSPECT FIRST.
Establish the evidence. Understand the building. Then decide what action is appropriate.
Published by OSCAR OnsiteCategory: Technical Consumer GuidanceLast reviewed: September 2026
Section 01
Do You Have a CIGA Guarantee?
CIGA guarantees have been issued in connection with cavity wall insulation installations across the UK for many years. If you have the original guarantee, keep it safely with the permanent records for your property.
If you do not have it, try to establish:
whether a CIGA guarantee exists
the guarantee number
the date the insulation was installed
the company that installed it
the type of insulation installed
what other documentation exists relating to the installation
Do not look at the guarantee in isolation. For an installation that may have been carried out 10, 15 or 20+ years ago, the history of the property since installation can be just as important.
Section 02
Before Making a CIGA Guarantee Claim
OSCAR recommends creating an evidence file before substantial remedial work is undertaken.
Installation Records
CIGA guarantee
Guarantee number
Original installation certificate
Installer name
Installation date
Insulation material/type
Original suitability assessment or survey
Compliance Records
Building Regulations information
Building Control documentation
Competent Person Scheme/self-certification information
Any certificate of compliance
Grant or funding documentation
Homeowner Information
Original aftercare guidance
Property maintenance information
CWI maintenance advice
Information explaining circumstances that could affect the insulation
Guarantee terms supplied at installation
Property History
Replacement windows or doors
Extensions
Structural alterations
Rendering or repointing
External wall penetrations
Previous damp or water ingress
Previous CWI inspections or remedial work
Evidence
Photographs
Survey reports
Borescope photographs/videos
Correspondence with the installer
Correspondence with CIGA
Previous complaints or claims
Records of relevant building repairs
THE OLDER THE INSTALLATION, THE MORE IMPORTANT THE CHRONOLOGY CAN BECOME.
Section 03
Was the CWI Installation Recorded for Building Regulations Purposes?
This is something OSCAR Onsite believes homeowners investigating historic cavity wall insulation should check. Cavity wall insulation in an existing building falls within Building Regulations notification and compliance arrangements.
Six Questions to Ask
1
Who installed the cavity wall insulation?
2
When was it installed?
3
How was the work notified for Building Regulations purposes?
4
Which Building Control or Competent Person Scheme route was used?
5
What compliance certificate or record was produced?
6
Was that documentation actually provided to the homeowner?
A historic Building Regulations or Competent Person Scheme record may provide useful contemporaneous evidence when reconstructing the history of an older installation.
What Was the Homeowner Told After the CWI Was Installed?
A cavity wall insulation guarantee may remain relevant for decades. If the subsequent condition and maintenance of the building can affect the insulation, an important question arises:
WHAT WAS THE HOMEOWNER ACTUALLY TOLD THEY NEEDED TO MAINTAIN?
Was written information provided explaining the importance of monitoring and maintaining:
mortar pointing
brickwork
render
external cracking
window seals
door seals
gutters
downpipes
roof and wall junctions
damp-proof course levels
external ground levels
ventilation
Was the homeowner told what to consider before:
replacing windows
replacing doors
extensions
new openings
boiler flues
extractor fans
air vents
drilling external walls
pipes or cables
other alterations to the external envelope
Was this advice provided? Was it provided in writing? Can it still be evidenced today?
Section 05
If Building Maintenance Matters, Homeowners Need to Know
CIGA's own historic published information has recorded cases where reported concerns were ultimately considered unrelated to cavity wall insulation and attributed instead to building maintenance or other building defects.
If deteriorated pointing, failed render, defective seals, gutters or another building defect can subsequently contribute to moisture entering or affecting an insulated wall, simply saying years later that "the building should have been maintained" raises another question:
WAS THE HOMEOWNER CLEARLY TOLD AT INSTALLATION WHAT THEY WERE EXPECTED TO MAINTAIN TO PROTECT THE CWI?
Section 06
A 25-Year Guarantee Needs a Long-Term Information Trail
A property could have CWI installed for one homeowner and be sold several times during the life of the guarantee.
Installation›Building Regs›Guarantee›Homeowner Info›Aftercare›Maintenance›Alterations›Inspections›Claim History
DOES THE INFORMATION FOLLOW THE PROPERTY?
When somebody purchases a property with existing CWI, do they receive:
the CWI guarantee
installation information
Building Regulations/compliance records
maintenance requirements
aftercare information
previous inspection records
records of alterations or remedial works
Section 07
The Property May Have Changed Since Installation
A cavity wall should not be assessed as though the property has remained frozen in time since the day the insulation was installed.
Windows & Doors
Have windows or doors been replaced? Have openings or lintels been altered?
Extensions
Has an extension been constructed against an originally insulated elevation?
External Walls
Has the property been repointed, rendered, coated or repaired?
Roof & Rainwater Goods
Have there been roof leaks, failed gutters, defective downpipes or alterations around eaves and gables?
Wall Penetrations
Have new boiler flues, vents, fans, pipes, cables or other penetrations been introduced?
Water Ingress
Has the property experienced penetrating damp, flooding, roof leaks or other significant moisture events?
Previous CWI Work
Has insulation previously been topped up, inspected, disturbed, partially removed or extracted?
Section 08
Ultimately, Somebody Needs to Look Inside the Cavity
Documentation tells us a great deal about history. It cannot tell us everything about condition today. Where concerns exist, the cavity itself may need specialist inspection.
A CWI inspection may consider:
whether insulation is present
insulation material/type
distribution and apparent coverage
voids and sparse fill
condition of the material
evidence of moisture
construction debris and mortar snots
cavity trays and weep holes
ventilation
external defects and relevant construction characteristics
PHOTOGRAPHED → RECORDED → MAPPED → RETAINED
Section 09
Damp Does Not Automatically Mean the CWI Has Failed
Damp and mould can have numerous potential causes.
condensation
inadequate ventilation
plumbing leaks
roof defects
failed gutters
defective downpipes
deteriorated pointing
cracked or defective render
inappropriate external ground levels
damp-proof course issues
penetrating moisture
thermal bridging
construction defects
cavity-related problems
DIAGNOSIS SHOULD BE BASED ON EVIDENCE — NOT ASSUMPTION.
Section 10
What if Voids or Missing Insulation Are Found?
Voids, sparse fill or inconsistent insulation distribution can be important findings. They need context.
LOCATION + EXTENT + DISTRIBUTION + CONSTRUCTION + ASSOCIATED EVIDENCE
Finding a void at one inspection point does not automatically establish the condition of the entire elevation. The evidence needs to be sufficiently representative.
Section 11
Why OSCAR Recommends Independent Inspection
There is an important distinction between investigating the problem and selling the remedy.
Investigating the Problem
Selling the Remedy
The questions should be:
What is actually in the cavity?
What condition is it in?
How consistently is it distributed?
Are other building defects present?
What has changed since installation?
What does the historic documentation show?
What does the photographic evidence show?
Is extraction actually justified?
EXTRACTION SHOULD BE THE CONCLUSION OF AN INVESTIGATION — NOT THE STARTING ASSUMPTION.
Section 12
Before CWI Extraction — Preserve the Evidence
Once insulation has been extracted, the original condition of the installation has been changed permanently.
Before substantial removal or disturbance, consider ensuring that:
the installation history has been established
relevant documentation has been collected
the condition of the external property has been recorded
appropriate cavity inspections have been undertaken
insulation distribution and defects have been photographed
other potential building defects have been considered
the reason extraction is being recommended has been clearly documented
PRESERVE THE EVIDENCE BEFORE CHANGING THE EVIDENCE.
Section 13
OSCAR Onsite's Technical Role in the CWI Industry
OSCAR Onsite does not approach CWI inspection simply as a company providing property surveys.
Cavity Wall Insulation Surveying & Inspection
Cavity Wall Insulation Extraction & Clearance
These qualifications were developed to establish structured occupational competency for those responsible for assessing existing cavity wall insulation installations and for those undertaking specialist extraction and clearance.
For homeowners who want an independent assessment before deciding what to do next, OSCAR Onsite provides a dedicated Cavity Wall Insulation Condition Inspection Survey.
what is present
what condition it is in
how the insulation is distributed
what relevant external/property risks exist
what the historic evidence tells us
what further action the evidence supports
Property
↓
Construction
↓
External Risk Factors
↓
Cavity
↓
Insulation
↓
Photographic Evidence
↓
Findings
↓
Recommendations
Concerned about a CIGA-guaranteed CWI installation?
If you know or believe that CWI at your property was covered by a CIGA guarantee but no longer have the certificate, contact CIGA regarding the records they hold.
OSCAR Onsite is aware that CIGA currently charges customers more than £50 to obtain a copy/replacement guarantee certificate. In OSCAR Onsite's view, this is an excessive charge for a homeowner seeking documentation concerning a long-term guarantee provided in connection with works undertaken to their property.
£50+ FOR A COPY GUARANTEE?
Section 16
What Information Does CIGA Hold About You?
A Subject Access Request is not the same thing as purchasing a replacement guarantee certificate.
Replacement Guarantee Certificate — A request for another copy of a specific guarantee document.
Subject Access Request — A request by an individual for access to personal data an organisation holds about them.
Potentially relevant personal information might exist within:
registration information
installer submissions
correspondence
emails
telephone/call notes
enquiries
complaints
previous claims
inspection information
historic administration records
replacement guarantee records
other records connected with the individual
A Subject Access Request provides rights of access to personal data. It does not automatically entitle an individual to an exact unredacted copy of every original document held. See the ICO guidance on your right of access.
Section 17
Free OSCAR CIGA Subject Access Request Template
Free OSCAR Onsite Resource
CIGA Subject Access Request Template
To help homeowners understand and exercise their data rights, OSCAR Onsite has prepared a free template that can be adapted when making a Subject Access Request to CIGA. No registration, email or marketing sign-up is required.
Suggested CIGA Subject Access Request
SUBJECT ACCESS REQUEST – CAVITY WALL INSULATION GUARANTEE AND INSTALLATION RECORDS
Dear CIGA Data Protection Team,
I am writing to make a Subject Access Request under Article 15 of the UK GDPR and the Data Protection Act 2018.
Please provide a copy of the personal data that CIGA holds about me in connection with the cavity wall insulation installation, registration and/or CIGA guarantee associated with the following property:
Property address:
[INSERT FULL ADDRESS]
CIGA guarantee number, if known:
[INSERT]
Approximate installation date, if known:
[INSERT]
Name(s) potentially associated with the records:
[INSERT]
My request includes personal data held in connection with the installation or guarantee, including where applicable personal data contained within registration records, installer submissions, correspondence, emails, telephone records, complaints, enquiries, claims, inspection records and historic administration records.
For the avoidance of doubt:
I AM REQUESTING ACCESS TO MY PERSONAL DATA. I AM NOT MAKING A REQUEST TO PURCHASE A REPLACEMENT CIGA GUARANTEE CERTIFICATE.
If you require reasonable additional information to verify my identity or locate the relevant records, please let me know.
I would prefer the information to be supplied electronically.
Yours faithfully,
Name:
Address:
Email:
Telephone:
Section 18
Before Sending Your Request
add your full name
add the property address
add the guarantee number if known
add approximate installation date if known
include previous names if relevant
keep a copy
keep evidence showing when it was sent
retain the response with your permanent CWI/property records
Section 19
Build a Permanent CWI Record for Your Property
Guarantee›Installation Info›Building Regs›Aftercare›Maintenance›Alterations›Inspections›Photographs›Remedial Work›Claim History
BEFORE → DURING → AFTER
Section 20
What Could an Independent Inspection Find?
Not every CWI investigation needs to end in extraction.
No CWI Remedial Action
No evidence currently justifies intervention.
Further Investigation
Additional inspection or evidence is needed.
Building Maintenance or Repairs
A defect affecting the external envelope or another part of the building needs attention.
Localised Remedial Work
A particular area requires intervention rather than wholesale removal.
Refer to Installer or Guarantee Provider
The evidence identifies a matter appropriate for referral.
CWI Extraction
The evidence establishes that controlled removal is technically justified.
EXTRACTION SHOULD BE THE CONCLUSION OF AN INVESTIGATION — NOT THE STARTING ASSUMPTION.
Section 21
Before You Make an Irreversible Decision
If you are concerned about cavity wall insulation, the first question should not automatically be "How much will it cost to extract it?"
What was installed?
Who installed it?
When was it installed?
What documentation exists?
Was the installation recorded for Building Regulations purposes?
What aftercare information was provided?
What maintenance was expected?
What has changed at the property?
What is actually inside the cavity today?
What does the evidence show?
AND ONLY THEN: WHAT ACTION IS JUSTIFIED?
Section 22
Frequently Asked Questions
A CIGA (Cavity Insulation Guarantee Agency) guarantee is a long-term guarantee issued in connection with a cavity wall insulation installation. It is intended to provide the homeowner with recourse in the event of problems relating to the installation, subject to the applicable guarantee terms.
CIGA guarantees have commonly been issued for 25 years, but the precise duration depends on the specific guarantee issued for your installation. Always check your own guarantee documentation for the applicable term.
You should contact CIGA and refer to your guarantee documentation for the claims process applicable to your installation. Before making a claim, OSCAR recommends gathering your installation records, Building Regulations/compliance information, property history and independent inspection evidence so that the claim is properly supported.
No. Damp and mould can result from numerous causes including condensation, inadequate ventilation, plumbing leaks, roof defects, failed gutters, deteriorated pointing, defective render and other building defects. The cavity insulation may be relevant, but the property and cavity should be properly investigated before causation is assumed.
OSCAR's general approach is to preserve and document the evidence before substantial disturbance. Once insulation has been removed, evidence of its previous condition and distribution can be lost. An independent CWI Condition Inspection Survey can document the condition before any irreversible remedial work.
An OSCAR CWI Condition Inspection Survey (CIS) is a specialist assessment of the cavity wall insulation and relevant external property conditions, supported by cavity inspection and photographic evidence where appropriate.
OSCAR Onsite authored the specialist NVQ qualifications for CWI Surveying & Inspection and CWI Extraction & Clearance. Using a surveyor whose competency is aligned with these standards helps ensure the inspection is evidence-led rather than driven by a commercial incentive to sell extraction.
OSCAR Onsite authored the specialist NVQ qualification for Cavity Wall Insulation Surveying & Inspection, as well as the specialist NVQ qualification for Cavity Wall Insulation Extraction & Clearance.
Cavity wall insulation in an existing building falls within Building Regulations arrangements. The precise route and records applicable to a historic installation will depend on the circumstances and arrangements operating at the time. It is worth investigating what compliance record exists for your property.
Contact CIGA regarding the records they hold and the options available for obtaining guarantee information. OSCAR is aware that CIGA currently charges more than £50 for a copy/replacement guarantee certificate. You may also consider making a Subject Access Request for the personal data CIGA holds about you.
If CIGA holds personal data about you, UK data protection law provides rights of access to that personal information. A SAR is different from purchasing a duplicate guarantee certificate. See the ICO guidance on your right of access for further information.
No. A replacement guarantee certificate is a request for another copy of a specific document. A Subject Access Request is a request by an individual for access to the personal data an organisation holds about them. A SAR does not automatically entitle you to an exact unredacted copy of every original document held.
No. OSCAR can independently inspect a property and document its findings. Decisions concerning cover and liability under a CIGA guarantee remain matters for the guarantee provider and applicable guarantee terms.
INSPECT. EVIDENCE. UNDERSTAND. THEN ACT.
Independent cavity assessment before irreversible decisions.
OSCAR Onsite is independent of CIGA. An OSCAR inspection does not determine whether a CIGA guarantee claim will be accepted. Decisions concerning individual guarantees remain with the relevant guarantee provider and depend upon the applicable terms and circumstances.
Homeowners should refer to their own guarantee documentation and the guarantee provider for formal information concerning their individual cover. This guidance has been prepared by OSCAR Onsite based upon our practical experience of cavity wall insulation surveying, inspection, extraction, technical monitoring, training and industry practice.
OSCAR ONSITE AUTHORED THE TWO SPECIALIST NVQ QUALIFICATIONS FOR CAVITY WALL INSULATION SURVEYING & INSPECTION AND CAVITY WALL INSULATION EXTRACTION & CLEARANCE.