Confirm that this is the right route
For an ordinary house project, apply to the local authority rather than appointing a registered building control approver to issue retrospective approval. First establish whether there is already a valid building-control file: completing an existing application or resolving a reverted private case is different from regularisation. [4][5]
The route can address work carried out by a previous owner as well as your own work. If the alteration predates the statutory cut-off, do not promise a regularisation certificate; discuss the evidence and sale implications with the conveyancer. [6][7]
The process step by step
- Describe the work and establish its date. Collect whatever original plans, photographs and project records exist. The council needs to understand what was altered and which regulations applied. [1][2]
- Agree the application information. Drawings and construction details may be needed, together with proposals for remedial work. The precise submission depends on the project rather than a universal drawing pack. [2]
- Pay the council’s applicable charge. Check the current schedule or request an individual assessment. Do not assume an ordinary application fee is also the retrospective fee. [8][7]
- Provide access for inspection and agreed investigations. Finishes may have to be disturbed so the council can assess concealed work. [6]
- Complete the identified corrections and supply the outstanding evidence. Certification depends on the assessment, not simply on payment or the owner’s assurance that the building has stood for years. [1]
What opening up means
Inspection may require parts of the construction to be exposed, tested or sampled. Agree the locations and the evidence needed before arranging the builder, and allow for reinstating finishes afterwards. Camden warns expressly that decoration may need to be disturbed. [1][6]
Where an investigation or repair affects load-bearing construction, have a competent person assess it and plan any temporary support. HSE guidance requires the stability of the structure to be considered before potentially load-bearing parts are altered. Opening up should not become an improvised structural alteration. [9]
Which standards apply?
The statutory assessment concerns the building regulations applicable when the unauthorised work was carried out. It is not automatically a demand to rebuild every historic feature to today’s new-build specification. Equally, evidence of age does not demonstrate that the work met the requirements applicable then. [6]
The certificate records compliance so far as the relevant requirements can be ascertained through the process. Regulation 18 states that it is evidence, but not conclusive evidence, of that compliance. It should not be described as a guarantee of every concealed component or the whole house. [1]
Cost and programme
As a dated local example, Redbridge’s schedule effective 1 April 2026 applies a 50% uplift to the corresponding base charge excluding VAT for regularisation and identifies the regularisation charge as VAT-exempt. This is Redbridge’s charging method, not a London-wide tariff. The schedule also allows supplementary charges in specified circumstances. [8]
Budget separately for professional investigation, drawings, access, opening up, repairs and making good. Ask for a programme based on those tasks; a simple document recovery and a concealed structural problem cannot sensibly be given the same promised completion date. [2][8]