Legal and neighbours
What if an extension has no building-regulations approval?
Building-regulations approval and planning permission are different. A home survey can say whether an extension looks competently built. It cannot say the council approved it. Missing papers are for your solicitor, who may discuss regularisation or indemnity. Indemnity insurance does not make a wall safe. The survey’s job is the wall.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless a source says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What are the two different questions?
Planning permission, or permitted development as the Planning Portal describes it for extensions in England, is about the principle and the size and position of what was built. Building regulations, as GOV.UK describes them, are about structure, fire, moisture, drainage, ventilation and the rest of how it was built. You can have one and not the other. A survey that says the flat roof looks tired has not answered either legal question.
What can the surveyor say about the extension?
Whether the junction with the house is cracked or leaking, whether the roof holds water, whether the opening where a wall was removed looks properly supported, and whether they could see the foundations (they usually cannot). Those are condition. “No papers seen” is a legal flag, not a condition rating. Ask them to keep the two sentences apart so your solicitor and your builder are not reading the same line.
- Is the beam or lintel over the opened-up wall visible, or only guessed?
- Does the roof drain back toward the house?
- Are there cracks at the joint between old and new?
- Were the electrics and drainage commented on, or excluded?
What paperwork should the solicitor ask for?
Planning permission or evidence of permitted development, building-regulations approval and a completion certificate, or a competent-person certificate where that route was used. If they are missing, the solicitor may discuss a regularisation application with the council, or an indemnity policy. Regularisation is the council looking at the work. Indemnity is an insurance policy with exclusions. Neither is a guarantee the roof is sound. Read the survey for that.
Why will this page not tell you it is fine after a number of years?
Enforcement time limits are legal rules with exceptions, and they are not a substitute for a wall that is leaning. A deadline that stops the council acting does not stop rain coming in, and it does not bind a lender who has their own rules. Your solicitor should explain the current position for this extension. Anyone who quotes a single number of years as if it cured the building is guessing.
Common questions
If the seller offers indemnity insurance, can you ignore the survey?
No. Indemnity, if it is offered and if the insurer accepts the risk, is about specified legal costs. It does not rebuild a failed junction. Read the policy schedule and read the survey. They answer different questions.
What is building-regulations regularisation?
It is the route GOV.UK describes for getting approval after work is done, which can involve the council inspecting and asking for openings-up. It is not automatic and it is not always granted. Your solicitor and the council explain it. The survey does not apply for it.
The agent says it was permitted development. Is that approval?
Permitted development is a set of national rules the Planning Portal explains, with limits and exceptions. “The agent said” is not those rules. A lawful development certificate is how people prove it later. Ask the solicitor whether one exists.
Will a lender care about missing papers?
Many do. Ask the lender or the broker with the facts, not with a hope. This page does not speak for them. A retention or a refusal is their decision. It is still not a description of the crack.
Are conservatories exempt from building regulations?
Some largely glazed extensions have been treated differently, and the exemptions have conditions. GOV.UK and the Planning Portal are where those conditions live. Do not rely on a salesperson’s “conservatories don’t count”. If it is heated and open to the house, ask specifically.
Is a loft conversion an extension for these purposes?
It is building work, and it often needs building regulations even when it does not need planning permission. The survey looks at the structure it can see, including whether the floor and the stairs were thought about. Papers are still the solicitor’s question. Party walls may be a third question.
The extension looks fine. Why worry?
Looking fine on the day is what a visual survey records. Missing structure inside a boxed-in beam is what it cannot see. If the report is relaxed and the papers exist, you have two consistent answers. If the report is relaxed and the papers are missing, you still only know the outside of the question.
What does it cost to regularise an extension?
The council publishes its own fees, and any opening-up is extra. This page does not copy a fee that varies. Ask the building-control team for this authority. Do not add a round number from a forum to your offer and call it advice.
Sources
Key facts
- Two regimes
- Planning is about whether you may build it. Building regulations are about how it is built. GOV.UK treats them separately.
- Survey
- Looks at structure, damp, roof and junctions it can see. It does not issue a completion certificate.
- Indemnity
- A policy may cover the cost of enforcement in defined events. It does not repair a roof that was badly built, and it is not a survey.
- Time limits
- This page does not state a year after which all unauthorised work becomes lawful. Ask the solicitor. The exceptions matter.