StructuralEngineer.ie's summary of opinion of compliance vs certificate of compliance: a Certificate of Compliance on Completion is a statutory BCAR certificate for works over the thresholds, such as extensions over 40 m², inspected under a plan from commencement and lodged with the building control authority. An opinion of compliance is a professional's signed opinion, used for exempt works or works done without statutory certification.
Side by side
| Opinion of compliance | Certificate of Compliance on Completion | |
|---|---|---|
| Basis | Professional opinion | Statutory (BCAR, S.I. 9 of 2014) |
| Used for | Exempt works, internal alterations, past works | New houses, extensions over 40 m², works needing a Fire Safety Certificate |
| When | During or after works | Planned from commencement, signed at completion |
| Inspections | As agreed, sometimes after the fact | Under a lodged inspection plan |
| Lodged publicly | No | Yes, on the building control register |
Which one your works need
- Removed internal wall, attic conversion, garage conversion, small exempt extension: opinion of compliance
- Extension over 40 m² (certified route): Certificate of Compliance on Completion, plus the planning position
- Extension over 40 m² where the owner opted out: no statutory certificate, so an opinion of compliance is usually what the buyer’s solicitor asks for
Why timing matters
An opinion of compliance is strongest when the professional inspected during the works: foundations before concrete, steel before boxing in. After the fact, they can only certify what they can see or verify, which may mean opening up. Getting the engineer involved before the work starts is what makes the paperwork straightforward later.
Bottom line
Statutory certificate for works caught by BCAR, opinion of compliance for everything else, and both are easiest when the inspections happen during the work. For an opinion of compliance with a fixed fee, call 01 270 9764.
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Frequently asked questions
Will a buyer's solicitor accept an opinion of compliance?
For works that didn't need statutory certification, such as exempt extensions, internal alterations and attic conversions, an opinion of compliance from a suitably qualified professional is the standard document. For works over the BCAR thresholds, solicitors expect the statutory certificates.
Can an opinion of compliance be given for works done without an engineer?
Sometimes, after inspection and, where needed, limited opening-up to verify hidden elements. The opinion can only cover what can be verified.
Who can give an opinion of compliance?
Typically a registered architect, registered building surveyor or chartered engineer with professional indemnity insurance. Solicitors check qualifications.
Sources
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