Retrospective Building Regulations: Your 2025 Guide to Regularisation

What is A Regularisation Certificate?

Retrospective certification applies to building work that has already been carried out—whether completed in the past or started recently, without proper approval.

Only your local authority’s building control team can issue this type of certification. Private inspectors are not permitted to do so.

Where works were carried out without building regulations approval, the owner can face enforcement action and prosecution, especially if the work is deemed to be structurally unsound.

That said, the local authority allows for retrospective certification through the process known as regularisation. The process covers unauthorised work started on or after 11th November 1985 and is covered under section 18 of the Building Regulations 2010.

Do Older Works Need Approval?

Some may not need approval at all. For example, if they were carried out before regulations required approval, or before Completion Certificates were introduced.

Certificates only became mandatory in 2013. Previously, certification was often requested by solicitors during property sales to demonstrate that the owner had carried out building work in accordance with the building regulations.

So, in historic cases, the absence of certification may be excusable if you can clearly demonstrate when and what works were carried out.

However, complications often arise when multiple contractors have altered or extended the original works over time. Layered work presents various challenges and may often need to be treated as a single unit of work.

Why Missing Certification Affects Your Property Sale

We usually hear from homeowners who discover the issue just as they’re selling their property. As the sale progresses, they realise that past works need approval.

The Risks of Missing Certification

A buyer without certification has no real idea of what they’re getting into. Not only do they face potentially costly remedial works, but also under Section 36 of the Building Act 1984, local authorities can seek injunctions to remove or improve non‑compliant works. Either way, the risks will often deter buyers and can be a major cause for a sale to collapse.Resolving the issue through the local authority under the regularisation process will require a formal retrospective application with well-crafted plans showing both the unauthorised work and the proposed remedial work.

Bear in mind:

• The local authority may require works to be “opened up” for inspection.
• Non‑compliant works must be rectified.
• Fees are higher than if approval had been sought at the time of construction.

The regularisation route is, however, always the most effective route.  

Indemnity Insurance vs Regularisation

This option certainly provides a more convenient method of cover for previous works, but is far less effective.

• The insurance only protects against the current sale and the cost of legal action from the local authority. It is often cited that legal action can only occur 12 months after work has been completed, but if the structure is dangerous, this is not the case.
• The policies become invalid if anyone makes an approach to the local council to ask about a lack of a building regulation certificate during the sale.
• It does not validate the construction work itself and leaves the underlying problem unresolved, often forcing price reductions or buyer withdrawal.

What if the work has been started or is recently completed?

Sometimes a homeowner is unaware approval is needed (it’s not uncommon for people to believe planning permission alone is enough) or their contractor has failed to advise them correctly. Budget constraints can also prevent compliance. In such cases, a regularisation certificate should be obtained as quickly as possible and certainly before the works are completed. Our advice would be to stop until an application has been made and avoid the ‘opening up’ process. For a rundown of how an application works have a look at our services page here.

What happens if you don’t get building regulations?

If you don’t get building regulations approval, you risk a lot of potential problems: unsafe and uncompliant work, enforcement action and your ability to sell the property in the future. 

Need Help?

If you are considering a retrospective application, please contact us here.

We can guide you through the process and help ensure your property meets compliance requirements quickly and within your budget.