Selling a House With No Planning Permission or Building Regs Sign-Off: What Your Buyer's Solicitor Will Ask and How to Fix It

01

What the buyer's solicitor is asking for, and why

Three documents drive the questions.

1. The TA6. The seller completes the Law Society's TA6 Property Information Form. The 6th edition replaced the 4th and 5th and has been mandatory for Conveyancing Quality Scheme firms for instructions on or after 30 March 2026 (Law Society TA6 page). Its explanatory notes cover planning permission, building regulations and competent person certificates at questions 5.1 and 5.2. They tell sellers to give their solicitor planning permissions and building control consents, and, if documents are lost or missing, to say so. The notes also say that "sellers should consult their solicitor if unsure whether work to the property required planning permission".

2. The lender's rules. If the buyer has a mortgage, the buyer's conveyancer follows the UK Finance Mortgage Lenders' Handbook (voluntary for lenders; each lender can add its own requirements). Part 1 paragraph 5.5 covers planning and building regulations (the live site blocks automated access, so here is an archived copy of Part 1 captured 6 March 2026). Para 5.5.1 says that where there is evidence of a breach but "in your professional judgment there is no reasonable prospect of enforcement action", and the conveyancer can provide an unqualified certificate of title, "we will not insist on indemnity insurance and you may proceed". Para 5.5.2 requires a report to the lender only where outstanding conditions will not be satisfied by completion and the conveyancer cannot give an unqualified certificate of title. That is the flexibility that makes some sales work on a short paper trail, and also why a conveyancer will need your evidence of age and compliance.

3. The local search. A CON29 search asks about formal action only. Q3.9 lists notices such as enforcement notices, breach of condition notices and planning contravention notices; Q3.8 asks only whether the council has "authorised ... any proceedings for the contravention of any provision contained in building regulations". An unauthorised extension that the council has never acted on does not show up, which is why the TA6 and the paperwork matter more than the search.

02

Step 1: gather the evidence

Before choosing a route, collect what exists:

• Planning: decision notices and approved drawings from the council's planning portal and archive. See how to check the planning history of a property and how to find approved planning drawings. An empty online search is not proof that nothing exists, so ask the council's planning records team too.
• Building regulations: the completion certificate or a private approver's final certificate (Building Regulations 2010 reg 17; SI 2024/110 reg 13), and any competent person certificate (for example Fensa for windows, Gas Safe for boilers). Installers must give the occupier a certificate and notify the council within 30 days, and councils must store what they receive (reg 20(3) and (3A)). See no building regulations completion certificate.
• Dating evidence: dated photographs, builders' invoices, utility and council tax records, satellite imagery, and statements from neighbours or the builder. You will need these to prove when the work was substantially completed.

03

Step 2: did it need permission at all?

Many "unauthorised" extensions turn out to have been lawful. Section 191(2) says operations are lawful if "no enforcement action may then be taken in respect of them (whether because they did not involve development or require planning permission or because the time for enforcement action has expired or for any other reason)" (TCPA s191(2)). So there are two ways in: the work needed no permission, or it is immune.

Permitted development. The work may have been permitted development when it was built, in which case no application was needed. Today's householder limits in Class A of the GPDO are, for example, a single-storey rear extension up to 3 m deep (4 m for a detached house) and up to 4 m high, and a two-storey extension up to 3 m deep and at least 7 m from the rear boundary (A.1(f) and (h)). Work done under an older version of the rules is judged by whether it needed permission when built, so ask a planning professional to check the rules that applied then. Our guide to planning permission for an extension has the current detail.

"Original house" starts in 1948. The GPDO allowances are measured from the "original" house, which article 2(1) of the GPDO defines, for a building existing on 1 July 1948, as the building "as existing on that date" and, for a building built on or after that date, as "as so built". The government's technical guidance puts it the same way. Work that was already there on 1 July 1948 is part of the original house, not an extension to it.

Slightly over a limit? Ask a planning professional whether reducing the extension would leave something the council would accept as lawful. Do not assume it works: permitted development does not apply "in connection with an existing building" where the building operations involved in constructing it are unlawful (GPDO art 3(5)(a)). A proposed lawful development certificate (s192) is the formal way to test a specific proposal. The fee is half the full application fee (MHCLG schedule: £274 for a householder extension, which is half of £548).

04

Step 3: is it immune from enforcement?

The rule. For a breach consisting of building works, no enforcement action may be taken after 10 years from the date the operations were substantially completed (England); for a change of use of a building to a single dwellinghouse, 10 years from the breach (TCPA s171B(1)(a) and (2)(a)). That is the position since 25 April 2024.

The transitional rule. You may read that "councils only have 4 years". That is now only partly true. SI 2024/452 reg 5 says the 10-year amendments "do not apply where ... the operations were substantially completed", or, for a change of use to a single dwelling, "the breach occurred, before the day on which that section comes into force", meaning 25 April 2024. So the old 4-year limit still applies to work substantially completed before 25 April 2024. It is not "breaches before 25 April 2024" in general: building work started before that date but completed after it is on the 10-year clock. The government's own enforcement guidance sets it out in PPG 17b-004.

What that means for a seller, as at 20 October 2026 (our derivation from the statute, not a quotation):

Exceptions that stop the clock. Immunity does not help where:

• There was deliberate concealment. The council can apply to a magistrates' court for a planning enforcement order (s171BA), which the court may make only if satisfied, on the balance of probabilities, that the breach was deliberately concealed to any extent and that making the order is just (s171BC). The courts have held that the s171B time limits do not start until a deliberately concealed breach is discovered (PPG 17b-004, citing Welwyn Hatfield and Jackson). A lawful development certificate cannot be granted while the time for a planning enforcement order has not expired (s191(3A)).
• Enforcement action was already taken. Further action is allowed within 4 years of earlier action on the same breach (s171B(4)(b)), and the issue of an enforcement warning notice in England counts as enforcement action (s171A(2)(za)).
• The building is listed. Unauthorised works to a listed building are a criminal offence (Listed Buildings Act s9), and the listed building enforcement power in s38 carries no time limit of its own. Demolition in a conservation area counted as "relevant demolition" has no limit either (s171B(2A)).

Immunity is a planning concept. It does not touch building regulations. Section 36 of the Building Act now lets a council act for 10 years from completion of the work, and the transitional rule saves only notices given before 1 October 2023, not older work (Building Act s36(4); SI 2023/993 reg 7). Our guide to planning enforcement time limits sets out the planning clock in full.

Proving the date. The burden is on you. The government's guidance says the applicant "is responsible for providing sufficient information to support an application", and that where the council has no contrary evidence there is "no good reason to refuse" if the applicant's own evidence is "sufficiently precise and unambiguous to justify the grant of a certificate on the balance of probability" (PPG 17c-006). An application must include "such evidence verifying the information included in the application as the applicant can provide" (DMPO art 39(2)(b)).

Statutory declarations. Statements from the builder, neighbours or the owner are often given as statutory declarations. The Statutory Declarations Act 1835 s18 lets a justice of the peace, notary public or other officer authorised to administer oaths take a declaration made voluntarily in the form in the Act's Schedule, and a knowingly false material statement in one is a criminal offence carrying up to two years' imprisonment or a fine (Perjury Act 1911 s5). It is also an offence, if done knowingly or recklessly (or, for documents and withholding information, with intent to deceive), to make a false or misleading statement, use a false or misleading document or withhold material information to obtain a lawful development certificate, punishable by up to two years' imprisonment or a fine on indictment (TCPA s194; see also PPG 17c-013).

05

Choose a route

Indemnity insurance

A lack-of-planning or building regulations indemnity policy is the fastest route. One published sample wording (CLS/ERGO, version dated 1 March 2016) pays for legal costs relating to an enforcement notice, the cost of altering or demolishing if required, and the fall in value caused by enforcement action, and runs "in perpetuity". Its statements of fact required that neither the seller nor the buyer "have communicated with the local planning authority" about building regulations irregularities, a general condition barred communicating about the insured risk with a third party without the insurer's consent, and it excluded loss from a retrospective building regulations application made without the insurer's consent. It dates from 2016, so use it only as an illustration of the types of condition, and read the wording of any actual policy. Full detail: planning indemnity insurance.

Existing lawful development certificate

This is the route for work that is lawful or immune. Section 191(4) says that if the council is "provided with information satisfying them of the lawfulness" of the operations, it "shall issue a certificate"; otherwise it must refuse. Planning merits are irrelevant, and a refusal is "not necessarily conclusive that something is not lawful": it may mean insufficient evidence so far (PPG 17c-009). You can appeal a refusal (PPG 17c-012). The certificate is a planning document: it "does not remove the need to comply with ... the Building Regulations 2010" (PPG 17c-004). Our guide to lawful development certificate costs covers fees across categories.

Retrospective application

Section 73A lets the council grant planning permission for "development carried out before the date of the application", including development carried out without planning permission, and the permission can take effect from the date the development was carried out (s73A(1) to (3)). It is an ordinary fee-paying application (PPG fees). Three cautions apply:

• Intention counts against you. NPPF policy DM8(2): where unauthorised development was "intentional", based on evidence, "that fact should be given substantial weight in considering whether to grant planning permission" (NPPF 2026, DM8).
• One go at the merits. An enforcement notice issued after a related application cannot be appealed on ground (a) ("permission ought to be granted"), unless the notice came more than two years after the application ceased to be under consideration (TCPA s174(2A) to (2AB)).
• It is not always best. You may read that "retrospective permission is almost always the better option before selling". That is wrong where the work was permitted development or is already immune: an existing lawful development certificate fits those cases, rests on facts rather than planning judgement, and cannot be refused on merits. See retrospective planning permission for the full application process.

Regularisation

For missing building regulations sign-off on work from 11 November 1985 onward, the formal route is a regularisation certificate. It is not a rubber stamp: the council can require you to open up the work. See no building regulations completion certificate.

06

Timing against your chain

• Lawful development certificate: the council must give notice of its decision within 8 weeks beginning with the day after receipt of a valid application, unless you agree a longer period in writing (DMPO art 39(10)). It must first acknowledge and validate the application (art 39(7) to (9)).
• Retrospective application: 8 weeks for a householder application, or longer if agreed in writing (DMPO art 34).
• Regularisation: regulation 18 sets no decision deadline of its own.
• Indemnity: there is no statutory process, which is why it is common on short chains.

Start gathering evidence before you list, because the evidence takes longer than the form.

07

What not to do

• Don't misstate the TA6. A seller who gives a wrong answer risks a claim for damages under section 2(1) of the Misrepresentation Act 1967, which applies unless the seller proves they "had reasonable ground to believe and did believe" the facts were true. If you do not know, say so: the Law Society says more "not known" options were added in the 6th edition (press release).
• Don't ask your agent to leave it out. Under the Digital Markets, Competition and Consumers Act 2024, a trader's commercial practice is a misleading omission if it omits "information that the average consumer needs to take an informed transactional decision" (s227, in force since 6 April 2025).
• Don't contact the council before agreeing a route. If an indemnity policy is an option, the sample conditions above show why: contact can put the cover at risk. Agree the route with the buyer's solicitor first.
• Don't backdate or tidy evidence. Knowingly or recklessly making a false or misleading statement to obtain a certificate is an offence (TCPA s194).

08

Common myths

• "Councils only have 4 years." Only for work substantially completed before 25 April 2024 (SI 2024/452 reg 5).
• "No record means no permission." Not necessarily: check the archive, and consider permitted development and immunity (Step 2 and Step 3).
• "Retrospective is always best." Not where an existing lawful development certificate fits.
• "You must get an LDC before you can sell." It is optional: a person who wishes to ascertain lawfulness "may make an application" (s191(1)).

09

Wales, Scotland and Northern Ireland

Wales. The enforcement limit is 4 years for operations and for a change of use to a single dwelling, and 10 years for other breaches (TCPA s171B, which has separate Welsh limbs). The Building Act s36 limit became 10 years in Wales on 1 July 2026 (WSI 2025/1368). Lawful development certificates exist in Wales under the same s191. The £548 figure in this guide is England's fee schedule, so check the Welsh one.

Scotland. The planning enforcement limit is 4 years for operations and for a change of use to a single dwellinghouse, and 10 years for other breaches (TCP(S)A 1997 s124). The equivalent certificate is a certificate of lawfulness of existing use or development (s150). For building control, a warrant is needed before work starts, but a late application may be made any time before a completion certificate has been accepted (Building (Scotland) Act 2003 s8 and s15), and for work done without a warrant a completion certificate must certify compliance with the regulations as they stand when it is submitted (s17(4) to (6)).

Northern Ireland. The limit is 5 years for every breach (Planning Act (Northern Ireland) 2011 s132). The equivalent certificate is under s169. Building control is under the Building Regulations (Northern Ireland) 2012, including a regularisation certificate (reg 13).

11

Sources

Every legal statement above is taken from the provision linked at that point. The main primary sources:

• Town and Country Planning Act 1990: ss73A, 171A, 171B, 171BA, 171BC, 174, 191, 192 and 194; SI 2024/452 reg 5
• Development Management Procedure Order 2015: arts 34 and 39
• GPDO 2015 arts 2 and 3 and Sch 2 Part 1; GOV.UK technical guidance for householders (last updated 10 September 2019)
• GOV.UK: PPG lawful development certificates (17c); PPG: enforcement and post-permission matters (17b-004); PPG fees; MHCLG planning fees from 1 April 2026
• NPPF (published 17 August 2026), policy DM8
• Planning (Listed Buildings and Conservation Areas) Act 1990 ss9 and 38
• Building regulations: Building Regulations 2010 regs 17, 18 and 20; Building Act 1984 s36; SI 2023/993 reg 7; SI 2024/110 reg 13
• Conveyancing: Law Society TA6 (6th edition) explanatory notes, TA6 page and press release; UK Finance Lenders' Handbook Part 1 paras 5.5.1 and 5.5.2 (archived copy captured 6 March 2026); CON29 Q3.8 and Q3.9 (council reproductions)
• Evidence and offences: Statutory Declarations Act 1835 s18; Perjury Act 1911 s5; Misrepresentation Act 1967 s2; DMCC Act 2024 s227
• Nations: TCP(S)A 1997 ss124 and 150; Building (Scotland) Act 2003 ss8, 15, 17; Planning Act (NI) 2011 ss132 and 169; WSI 2025/1368
• Sample indemnity wording (2016): CLS Risk Solutions / ERGO

This guide is general information, not legal advice. For a specific sale, ask your conveyancer, who will know what your buyer's lender requires.