Quick summary: Regularisation Certificate
A Regularisation Certificate is retrospective Building Regulations approval from your local authority Building Control, used when work was carried out without the right Building Regs application or sign-off. It can be helpful if you’re selling, remortgaging, or simply want peace of mind — but it often involves inspections, opening-up works, and sometimes remedial upgrades.
- Best for: Missing Building Regs paperwork where you want a formal route to compliance (not just a paper workaround).
- Not a guarantee: Building Control can ask for evidence, expose-up, testing, and corrections before they’ll issue a certificate.
- Timescale: Often weeks to months, depending on what’s been done and what evidence is available.
- Costs: A council fee plus likely costs for drawings, structural input, opening-up and any remedial work.
If you’re unsure whether regularisation is the right approach (or whether another route is more sensible for your situation), our team can help you map out the least stressful path.
Found missing Building Regs paperwork and not sure what to do next?
Tell us what work was done (and roughly when) and we’ll explain whether a Regularisation Certificate is realistic — and what evidence you’ll likely need before you contact Building Control.
What is a Regularisation Certificate (in plain English)?
A Regularisation Certificate is a way to ask your local authority Building Control team to inspect work that was done without the correct Building Regulations approval at the time, and (if it meets the standard) issue retrospective sign-off.
Homeowners typically look into regularisation when they discover missing paperwork — often during a sale, remortgage, or after buying a property where the previous owner can’t provide a completion certificate.
What a regularisation certificate actually does
- It allows Building Control to assess compliance for work that’s already been done.
- It can provide a formal certificate for your records (useful for solicitors and lenders).
- It may require opening-up (removing plasterboard, lifting floors, exposing steel/insulation) so the inspector can see what’s hidden.
- If something doesn’t comply, you’ll usually be asked to remedy the issues before a certificate can be issued.
Do you need a regularisation certificate?
Not always. However, it’s worth considering if the work is significant, safety-critical, or likely to be questioned by a buyer’s solicitor. In practice, the “right” answer depends on what was done, how long ago, and what evidence you have.
Situations where a regularisation certificate is often sensible
- Structural alterations (removed loadbearing walls, inserted steels, major openings).
- Loft conversions (stairs, fire protection, insulation, escape route upgrades).
- Garage conversions (insulation, damp protection, ventilation, drainage changes).
- Extensions where you can’t show Building Regs sign-off.
- Electrical work where Part P certification is missing and the scope is unclear.
Situations where regularisation may not be the best first move
- Very minor works where the risk is low and there’s nothing safety-critical hidden.
- Where the project is very old and evidence simply doesn’t exist (your council can confirm what options are available).
- Where you’re on a tight sale timeline and regularisation would likely involve opening-up and remedial work.
Regularisation certificate vs completion certificate vs indemnity insurance
This is where many homeowners get stuck — and it’s also where well-meaning advice online can lead you in the wrong direction. These three things solve different problems.
Building Regulations completion certificate
- Issued when work was properly applied for (Full Plans or Building Notice) and inspected at key stages.
- It’s the “normal” outcome when Building Control is involved from the start.
- For more detail, see our guide to a Building Regulations completion certificate.
Regularisation certificate
- Used when Building Control wasn’t involved correctly at the time.
- It’s retrospective, so Building Control may need evidence and opening-up to assess what’s hidden.
- It can lead to remedial works before anything is issued.
Indemnity insurance
- Not a compliance certificate — it’s an insurance policy used in some sales where paperwork is missing.
- It does not prove the work is safe or compliant.
- Policies often have conditions (for example, contacting the council can affect eligibility). Always take legal advice before relying on it.
How Building Control assesses a regularisation certificate application
A building control regularisation certificate process is usually more involved than homeowners expect, because the inspector is being asked to sign off work they didn’t see at key stages. As a result, the council may ask for a combination of evidence, exposure, and professional input.
What Building Control may ask for
- Drawings (existing and as-built) showing what was actually constructed.
- Structural calculations (particularly for steels, openings, lofts and structural changes).
- Opening-up so insulation, fire protection, structure and damp measures can be inspected.
- Test certificates (electrics, gas, ventilation commissioning where relevant).
- Remedial upgrades if something falls short of the required standard.
If you want a bigger-picture view of what inspectors typically check on domestic projects, our guide to Building Control inspections explains it clearly.
Quick costs snapshot: regularisation certificate cost (what to budget for)
- Council regularisation fee: varies by local authority and project type (often similar to, or higher than, a standard application).
- Drawings / survey: if you need as-built plans to explain the work clearly.
- Structural engineer: commonly needed for loadbearing changes, steels, lofts.
- Opening-up and making-good: lifting floors, removing plasterboard, then re-finishing.
- Remedial works: upgrades to fire protection, insulation (Part L), ventilation, drainage, etc.
The “cheapest” route is usually the one where you already have good evidence (photos, calcs, specs) and the work is clearly compliant. The opposite is also true: if everything is hidden and undocumented, costs can climb quickly.
How long does a regularisation certificate take?
Timescales vary because Building Control can only move as fast as the evidence allows. A straightforward case with good documentation might be resolved relatively quickly. On the other hand, if opening-up reveals missing insulation, inadequate steels, or fire protection issues, the process can stretch out while upgrades are designed and completed.
What typically affects the regularisation certificate timescale
- How much is hidden: the more that’s covered up, the more opening-up is likely.
- How complex the work is: loft conversions and structural alterations usually take longer to evidence.
- Inspector availability: councils have different workloads and lead times.
- Remedial work: if you need upgrades, you’re effectively doing a mini-project.
If your scenario is specifically about “how long you have” to address historic Building Regs issues, our guide to retrospective Building Regulations time limits is worth reading as well.
How to get a regularisation certificate (step-by-step)
Here’s the calm, practical way to approach an application for a regularisation certificate without creating extra stress.
Regularisation certificate application checklist
| Step | What you do | Why it matters |
|---|---|---|
| 1) Identify what’s missing | Work out which project has no Building Regs paperwork (loft, extension, structural wall removal, etc.). | You don’t want to regularise the wrong thing — or miss a safety-critical element. |
| 2) Gather evidence | Collect photos, invoices, specs, any drawings, and any certificates (electrics/gas). | Good evidence reduces opening-up and speeds up decisions. |
| 3) Get technical support (if needed) | Commission structural calculations or as-built drawings where appropriate. | Building Control needs confidence on structure, fire safety and insulation performance. |
| 4) Apply to the council | Submit the regularisation application to your local authority Building Control with supporting info. | Regularisation is usually handled by the local authority (not a private inspector). |
| 5) Inspections + any remedial work | Allow for opening-up, inspections and corrections, then re-inspection. | The certificate is normally only issued once compliance is demonstrated. |
If you need drawings to explain what exists — or you want help packaging the evidence so Building Control can assess it properly — our guide to plans for Building Regulations explains what’s typically required.
Want help preparing the evidence Building Control will actually accept?
We can produce clear as-built drawings, highlight the likely compliance pinch-points, and help you avoid unnecessary opening-up wherever possible.
Regularisation certificate for loft conversions, roofs and other common works
Some project types come up again and again. If any of these sound familiar, it’s wise to assume Building Control will focus on the “hidden” details.
Regularisation certificate for loft conversion
- Fire safety (Part B): protected stair route, suitable doors, smoke alarms, and escape/egress considerations.
- Structure (Part A): steels, floor structure, load paths, and calculations.
- Insulation (Part L): roof/party wall build-ups and ventilation details.
- Stairs: pitch, headroom, guarding — a common snag point.
Regularisation certificate for roof works
- Thermal upgrades: re-roofing can trigger insulation expectations, depending on what was done.
- Ventilation and condensation control: especially for warm roof/cold roof changes.
- Structural adequacy: if rafters were altered or loads changed.
Regularisation certificate for extensions and conversions
- Foundations and drainage: often hidden and harder to evidence later.
- Damp proofing: DPC/DPM details can be a key inspection point.
- Glazing: safety glazing and thermal performance evidence.
Pitfalls and gotchas to avoid
Regularisation is doable in many cases, but it’s rarely “just a form”. These are the issues that most often cause delays, stress, and unexpected spend.
Common mistakes we see
- No photos and no way to show insulation, steels or damp measures without major demolition.
- Missing structural calculations for openings and loft floors.
- Assuming electrics are “fine” without any test certification or clear scope.
- Confusing planning with Building Regs and chasing the wrong paperwork first.
If you’re also trying to get your wider project paperwork in order (certificates, approvals, completion documents), our guide to certificates and compliance documents is a helpful checklist.
FAQs: Regularisation Certificate
What is a regularisation certificate in building control?
It’s retrospective approval issued by local authority Building Control for work that didn’t go through the correct Building Regulations process at the time. Building Control will usually inspect, request evidence, and may require opening-up or remedial work before issuing anything.
How do you get a regularisation certificate?
You apply to your local authority Building Control, provide details of the work, and then follow their inspection and evidence requirements. In many cases you’ll also need drawings, structural calculations, and potentially opening-up to prove what’s behind walls, floors or ceilings.
How long does it take to get a regularisation certificate?
It depends on complexity and evidence. Straightforward cases can move quickly, but anything involving loft conversions, structural works, or hidden insulation can take longer — especially if remedial upgrades are needed before sign-off.
How much does a regularisation certificate cost?
There’s usually a council fee, plus “practical” costs such as drawings, engineering input, opening-up/making-good, and any remedial work. The more evidence you already have, the more controlled the costs tend to be.
Is a regularisation certificate as good as a completion certificate?
It can be a strong alternative when the original completion certificate is missing, because it’s formal Building Control sign-off. However, it’s retrospective — so it may involve more scrutiny, evidence requests, and disruption than a standard Building Regs job that was inspected at key stages.
Who can issue a regularisation certificate?
Regularisation is typically handled by the local authority Building Control team. The exact route can vary, so if you’re unsure, check with your council before paying for drawings or opening-up works.
Do I need a regularisation certificate to sell my house?
Not always, but missing Building Regs sign-off can trigger solicitor enquiries and buyer concerns — especially for lofts, extensions, conversions and structural changes. Some sales proceed with alternative solutions (such as indemnity insurance), but that doesn’t prove compliance, so it’s worth weighing up the best option for your situation.
Not sure whether to regularise or take a different route?
We’ll help you understand the practical trade-offs (time, disruption, cost and risk) so you can choose the least stressful option for your sale or refinance.
Next steps & useful guides
If you’re sorting out missing approvals or planning a wider home project, these guides are a sensible next read:
- Building Control: What It Is, When You Need It, and How to Pass Inspections First Time
- Building Regulations: Complete Homeowner’s Guide
- Building Regulations Completion Certificate – What It Is and Why You Need One
- Retrospective Building Regulations Time Limit: How Long You Have to Apply and Prove Compliance
- Plans for Building Regulations – What Drawings You Need & When
- Certificates & Compliance Documents You Must Keep
- Building Control Inspections – What to Expect
- What it is Retrospective Building Regulations approval issued by local authority Building Control for work done without correct sign-off.
- When it’s used Typically during a sale/remortgage or when missing paperwork is discovered for lofts, extensions, conversions or structural work.
- What to expect Inspections, evidence requests, and often opening-up. Remedial work may be required before a certificate is issued.
- Costs Council fee plus likely costs for drawings, engineering input, opening-up/making-good and any upgrades.
- Key decision Whether you want formal compliance sign-off (regularisation) or an alternative route for the transaction — depending on risk, timeline and evidence.
Want a calm, practical steer? Message Plans Made Easy and we’ll outline your likely options and next steps.
Official guidance
For general UK homeowner guidance, it’s always worth checking official sources as well:
- Planning Portal – national guidance (planning and home projects)
- GOV.UK – planning permission guidance (England & Wales)
Ready to get your paperwork and compliance sorted?
Plans Made Easy can prepare clear drawings, help you organise evidence, and guide you through the Building Control process with minimal disruption.
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