Retrospective structural assessment for Building Regulations
An assessment of structural works that were completed without approval, so they can be regularised with Building Control.
About this service
A retrospective structural assessment looks at building work that was done without Building Regulations approval and checks whether it is structurally adequate. The usual examples are a load-bearing wall knocked through, a chimney breast removed, a loft converted or an extension built without anyone telling Building Control. Our report gives the council the structural justification it needs to consider a regularisation application.
These cases often surface during a sale, when a buyer's solicitor asks for completion certificates that do not exist. They also arise when an owner discovers that a previous owner's builder never applied for approval. The work may be perfectly sound, or it may hide undersized beams and missing padstones. The only way to know is to find out what was actually built and check it against current design standards.
That usually means some opening up, such as removing plaster at beam ends or lifting floorboards, followed by structural calculations. Fees start from £600 + VAT. Our assessment report is signed off by a chartered engineer who is a Member of the Institution of Civil Engineers (MICE), and we send it to Building Control and liaise with them, which keeps the process moving.
When you need it
- Walls were removed or an extension built without Building Regulations approval
- You're selling and the buyer's solicitor needs a regularisation certificate
- Building Control has asked for structural justification
What's included
- Inspection of the completed works
- Opening up where needed to confirm what was built
- Structural calculations to check adequacy
- Recommendations for any remedial work
How it works
- Gather the historyYou tell us what was done, roughly when and by whom, and share any drawings, invoices or photographs. We confirm the scope, likely opening-up locations and fixed fee in writing.
- Inspect and open upWe inspect the completed works and agree targeted opening up with you or your builder, exposing beam bearings, padstones, lintels or joist connections so we can see what was built.
- Check by calculationWe measure the members found and run structural calculations to current standards, checking beams, bearings, walls and foundations where these are relevant to the work.
- Recommend any remedial workIf something falls short, we explain what needs to change, such as adding a padstone or strengthening a beam, and whether remedial design is needed.
- Submit to Building ControlWe issue the retrospective assessment report for submission with your regularisation application and answer Building Control queries until they are satisfied with the structural information.
What you receive
Regularisation or indemnity insurance: choosing the right route
When unauthorised work comes to light during a sale, sellers are sometimes offered indemnity insurance instead of regularisation. Insurance protects against council enforcement, but it does nothing to confirm the structure is safe, and it may be invalidated once Building Control has been contacted. Regularisation takes longer but gives real assurance and a certificate. Our guide to retrospective Building Regulations approval explains how the council process works, and Building Control fees are paid separately.
Common findings include steel beams sitting on bare brickwork without padstones, timber lintels replacing a loaded wall, and loft floors built on the original ceiling joists. Where the work was a wall removal, our guide on steel beams and padstones shows what good practice looks like. If the problems are significant, remedial works design follows the assessment.
Not included
- Building Control fees
Projects that used this service
Frequently asked questions
How do I get building regulations approval for work already done?
You apply to your local council's Building Control for a regularisation certificate. They will usually need plans of the work and structural justification, and may ask for parts to be opened up for inspection. A structural engineer's retrospective assessment provides the calculations and evidence they require for the structural elements.
Will I have to take down the work if it was done without approval?
Rarely. In most cases the work can be regularised once it is shown to be adequate, sometimes with minor remedial items such as adding padstones or improving fire protection. Only where work is seriously deficient or unsafe would substantial changes be needed, and even then strengthening is usually possible rather than demolition.
Why does the engineer need to open up walls and ceilings?
Calculations only mean something if they are based on what was really built. Plaster and boarding hide beam sizes, bearings and connections. Small, targeted openings let us confirm these details, and Building Control often asks to see them too. We agree locations in advance so disruption and making good are kept to a minimum.
Can I sell a house with unapproved structural alterations?
You can, but buyers' solicitors and lenders will usually ask questions, and some purchases stall until the issue is resolved. Options include regularisation with Building Control or indemnity insurance. A retrospective structural assessment is the first step towards regularisation and gives the buyer confidence that the structure has been checked.