Knowledge Base
Planning, regulations and construction, explained.
Topic 21
Buying, selling and unapproved work
Check approvals and completion documents when buying or selling, and understand options for addressing unapproved work.
12 articles
Buying
01Buying a property you plan to extend: what to check firstCheck the planning position, title restrictions and physical feasibility before committing to a property whose value to you depends on extending it. A sale description or a neighbour’s extension is not approval for your own proposal.02Buying a house with an extension or loft that has no planning permission or sign-offA missing approval does not automatically mean the purchase must stop, but the legal position and the condition of the work need separate checks. Establish whether documents are simply missing, an application remains unfinished, or the work was carried out without the required approval.03Can an unapproved loft be sold as a bedroom?A property with an unapproved loft can be offered for sale, but the room should not be presented as an additional bedroom when that description is unsupported. Establish what use the conversion was approved for and disclose missing approvals clearly.
Selling
04Selling without a completion certificateYou may be able to sell without a completion certificate, but first establish why it is missing and what the buyer’s conveyancer and lender require. Recovering an issued certificate, completing an open application and regularising unauthorised work are different routes.05Indemnity insurance or regularisation: which is better?Neither option is universally better: indemnity insurance addresses defined financial risks, while regularisation is a council process for assessing eligible unauthorised building work. Choose according to the missing approval, the condition of the work and the requirements of the transaction.06What the buyer's solicitor will ask forThe buyer’s solicitor will seek evidence of the property’s legal position, the history of alterations and any unresolved approvals or disputes. Prepare a clear document trail rather than assuming that one planning decision or insurance policy answers every enquiry.
Putting it right
07Regularisation certificates: the process, the cost and opening up workRegularisation is the retrospective building-control process for eligible unauthorised work begun on or after 11 November 1985. The council may require drawings, opening up, tests and remedial work before it can issue a certificate; the application fee is not the whole cost.08Retrospective planning permissionRetrospective planning permission is an application to retain development carried out without the necessary permission or contrary to it. Approval is not guaranteed, and applying does not replace building-regulations approval or automatically stop enforcement.09Certificate of lawfulness for existing works and the 10-year ruleA certificate of lawfulness for existing development confirms the planning status of the specific work or use described in it. In England, the 2024 change introduced ten-year enforcement periods for newer building operations and single-dwelling changes of use, while preserving four-year periods for qualifying earlier cases.10A chimney breast removed years ago with no sign-offHave the remaining chimney and its support assessed, then establish the appropriate building-control route. The fact that a chimney breast was removed years ago does not show that the retained masonry is safely supported or that the work was approved.11A load-bearing wall removed years ago with no sign-offArrange a structural assessment and check the building-control history before treating an old wall removal as resolved. A visible beam, lack of obvious cracking or the passage of time is not, by itself, evidence that the opening was correctly designed and approved.12An extension built over a sewer without an agreementFirst establish whether the pipe is public, when the extension was built and whether an agreement was required for that work. Where Thames Water’s approval is missing, a retrospective assessment may be possible, but it is not guaranteed and may require evidence or changes to protect the sewer.