Why do most planning applications get refused?

Most applications are refused because the proposal conflicts with the council's Local Plan. This is almost always avoidable with the right preparation. Under s.38(6) PCPA 2004, applications must be determined in accordance with the development plan unless material considerations indicate otherwise. Common avoidable causes: not reading Local Plan policies before commissioning drawings; missing supporting documents; unaddressed environmental constraints (flood risk, trees, ecology — all checkable for free before submission). Refusals are predictable, not random. Every application is assessed against five categories: policy compliance, design quality, amenity impact, highways, and environmental constraints. Miss any one and the officer has a well-founded reason to refuse.

What are the three most common avoidable planning mistakes?

Three failures account for the majority of avoidable refusals — all preventable before a single form is submitted. 1. No pre-submission neighbour engagement. Talk to neighbours, document it, address what you can, and include the engagement in your planning statement. 2. Design that doesn't fit its context. Scale, massing, and materials must respect the surrounding area. The design and access statement must justify the design concept — not merely describe the proposal. 3. Unaddressed environmental constraints. Protected trees, flood zones, ecology, and contamination are all checkable for free. They are not surprises — they are failures of preparation.

Is pre-application advice worth it?

Yes — in almost every case. A householder pre-app costs £100–£500 and takes 4–6 weeks. A refused application that goes to appeal costs £5,000–£15,000 and takes 12–30 months. The officer's response identifies whether the principle is acceptable, which policies apply, what documents are required, and what design changes would strengthen the application. A response on file is also a material consideration — demonstrating good faith engagement. Book it before the architect produces detailed drawings.

Do I need planning permission for a house extension?

It depends on permitted development rights under the GPDO 2015 — but those rights can be removed, and assuming they apply without checking is a common and costly mistake. Detached houses: up to 8m rear extension under prior approval; up to 4m without. Semi/terraced: up to 6m under prior approval; up to 3m without. PD rights do NOT apply if: the property is listed; an Article 4 Direction applies (common in conservation areas); conditions on the original permission removed them; or previous extensions used the allowance. A Certificate of Lawful Development provides formal written confirmation — strongly recommended even where PD rights clearly apply.

What happens if you build without planning permission?

REPLACE THIS — see flag (a). The visible text references the abolished four-year rule. Correct the page to the current 10-year rule (England, from 25 April 2024), then paste the corrected visible wording here verbatim.

What is a Local Plan and why does it matter?

The Local Plan is the legally binding document controlling what can be built in your area. Under s.38(6) PCPA 2004, all applications must be decided in accordance with it. If your proposal conflicts with it, it will be refused. It sets out where development will go, density requirements, design standards, affordable housing percentages, and environmental designations. Your Local Plan is publicly available on your council's planning portal. Read it before commissioning drawings. If a council's Local Plan is more than five years old without active review and cannot demonstrate a five-year housing land supply, the plan may be out of date — triggering a 'presumption in favour of sustainable development' under NPPF Para.11. Experienced developers actively look for councils with out-of-date Local Plans.

What is a material planning consideration — and what isn't?

A material planning consideration is any factor an officer or committee can lawfully take into account. Decisions made on non-material grounds are legally vulnerable. Material: policy compliance, design quality, amenity impact (overlooking, overshadowing, loss of light, noise), highways, flood risk, ecology, heritage, public benefit. Not material: effect on property values; personal disputes; competition concerns; moral objections; general opposition to change. None of these can lawfully influence a planning decision. A committee that refuses on non-material grounds exposes the council to a costs award at appeal.

Does the Green Belt actually protect beautiful countryside?

No. The Green Belt is a spatial planning policy to prevent urban sprawl — not a nature or landscape designation. High ecological or landscape quality is not required for Green Belt status. England has 1.6 million hectares of Green Belt. A significant proportion is scrubland, degraded agricultural land, golf courses, and car parks — receiving almost the same planning protection as a National Park despite a fraction of the ecological value. The designations that actually protect landscape and ecology are National Parks, National Landscapes (formerly AONBs), and SSSIs — separate designations with separate legislative bases. The December 2024 NPPF introduced 'grey belt' — lower-quality Green Belt land to be released before higher-quality land.

We built it without permission…now we’re selling

7 Aug

Written By Tom Weighton

We Built It Without Permission — Now We're Selling. What Happens? | PlanWiser

This is one of the most common enquiries we find in our day-to-day work and one that can often cause the buyer's solicitor to hold up a sale. This article details possible solutions as well as how long they are likely to take.

What the buyer's solicitor is actually asking

How the enquiry arises, and the two separate records being checked. Inline SVG, no external assets.

The enquiry is rarely "did you have planning permission". It is broader than that: show me that this building is lawful.

Most home extensions in England never needed permission at all. They were built under permitted development rights granted by GPDO 2015, Sch. 2 Pt. 1, which allows a defined envelope of work without any application. If your extension sits inside those limits, there is no permission to produce because none was ever required — and nothing is wrong. The first job is therefore to measure what you built against the permitted development limits.

Two nuances of the legislation that are important to understand: first is the original dwellinghouse test — "original" means as built, or as it stood on 1 July 1948, not as it stood when you bought it. A 1990s conservatory you inherited eats your house's allowance. The second is that permitted development rights can have been removed from your property entirely: by an Article 4 Direction or conservation area designation, or by a condition on the permission that created the estate. Plenty of homeowners have built lawfully-shaped extensions on properties where the rights had already been withdrawn.

Note too that planning and building regulations are separate regimes with separate consequences. This article is about the planning side, but you will also need a building regulations completion certificate.

Is it already immune from enforcement?

The transitional rule under SI 2024/452. Which limit applies turns on the date of substantial completion. Inline SVG, no external assets.

If the work did need permission and never had it, it is unlawful — but unlawful is not the same as enforceable forever. Section 171B of the TCPA 1990, s.171B sets a time limit after which the council can no longer act, and the building becomes lawful by the passage of time.

That limit changed. LURA 2023, s.115 replaced the four-year limit for building operations with a single ten-year limit across all breaches in England, in force from 25 April 2024. The detail that matters at sale is the transitional provision in the commencement regulations: the new ten-year limit does not apply where the operations were substantially completed before 25 April 2024. Those builds keep the old four-year rule.

The three routes — and how to choose between them

The order of decision: lawfulness first, then timescale. Inline SVG, no external assets.

Route one — lawful development certificate (existing)

An application under TCPA 1990, s.191 asks the council to certify that what stands is lawful — either because it never needed permission, or because the enforcement period has expired. It is decided on fact and law, not on planning merits. The council cannot refuse it because the design is ugly or the neighbours object.

The fee is £548 and may take eight weeks. The evidence usually needed is: a signed statutory declaration from you and ideally from the builder, dated photographs, invoices and bank records, delivery notes, Council Tax or utility correspondence showing the property in its altered form, and historic aerial or street-level imagery.

Route two — retrospective planning application

Where the work is unlawful and not yet immune, TCPA 1990, s.73A allows you to apply for permission for development already carried out. The fee is the same as above and your property is judged exactly as it would have been before you built.

This route carries the real risk. You are handing the council a documented breach with an address attached. If it is approved, the problem is gone and the sale proceeds. If it is refused, the authority now knows, and an enforcement notice becomes a possibility.

Route three — indemnity insurance

A one-off policy, typically a few hundred pounds on a residential extension, that pays out if the council enforces. Many lenders and solicitors accept it. It is the pragmatic answer when the risk of enforcement is low and the completion date is close.

Route comparison

Cost, timescale and what each route actually proves

Route	Fee	Timescale	What it gives the buyer
Lawful development certificateTCPA 1990, s.191	£548	8 weeks+	Formal confirmation the building is lawful. Retires the issue permanently. Requires strong dated evidence.
Retrospective applicationTCPA 1990, s.73A	£548	8–16 weeks	Full permission if granted. Judged on merits, so a refusal exposes the breach and can trigger enforcement.
Indemnity insuranceVia your conveyancer	Low £100s	2–5 days	Financial cover only. Fast and lender-friendly, but the building stays unlawful and the issue recurs at the next sale.

Fees are the England householder rates and exclude the Planning Portal service charge (approx. £65). Timescales are typical rather than statutory; the statutory determination period for both applications is eight weeks.

What you have to tell the buyer

The disclosure points that surface an unauthorised extension. Inline SVG, no external assets.

The TA6 property information form asks directly about alterations, planning permissions, building regulations approvals and any correspondence from the council. Answer honestly. The cost of this route is almost always smaller than the retention it prevents.

Data sources

Town and Country Planning Act 1990 — ss. 171B, 171BA, 191, 73A: enforcement time limits, planning enforcement orders, lawful development certificates, retrospective applications.
Levelling-up and Regeneration Act 2023, s.115 — replacement of the four-year limit with a ten-year limit in England.
The Planning Act 2008 (Commencement No. 8) and Levelling-up and Regeneration Act 2023 (Commencement No. 4 and Transitional Provisions) Regulations 2024 (S.I. 2024/452) — commencement on 25 April 2024 and the transitional provision.
Town and Country Planning (General Permitted Development) (England) Order 2015 — Schedule 2, Part 1: householder permitted development limits.
Planning (Listed Buildings and Conservation Areas) Act 1990, s.9 — offence of unauthorised works to a listed building.
Planning Portal — current application fees and the online service charge.

Limitations of this guidance

England only. Enforcement time limits in Wales, Scotland and Northern Ireland differ, and the four-year rule has not been abolished in Wales.
General guidance, not advice on your property. Whether a specific structure is lawful turns on measurements, dates and local designations that cannot be assessed from an article.
Fees, legislation and national policy change. Check the current fee before applying.
Indemnity insurance terms vary by insurer; your conveyancer arranges and advises on the policy, not your planner.
No outcome is guaranteed. A certificate depends on evidence; a retrospective application depends on planning merits.

FAQs

Can I sell a house with an extension that has no planning permission?

Yes. Nothing in planning law prevents the sale, and thousands of these transactions complete every year in England. What changes is the paperwork. Your buyer's solicitor will raise an enquiry, the buyer's lender may want the position resolved before releasing funds, and you will have to answer the TA6 property information form honestly. The practical question is not whether you can sell but which route you use to satisfy the enquiry: a lawful development certificate, a retrospective planning application, or indemnity insurance. Each has a different cost, timescale and effect on the sale price. Pick the wrong one and you can lose weeks in a chain or hand the buyer a reason to negotiate. If you are unsure which route your situation calls for, the free PlanWiser planning quiz will point you at the right one in a few minutes.

How long before an unauthorised extension becomes lawful?

In England the time limit for enforcement action against building work is now ten years from the date the operations were substantially completed. That came in on 25 April 2024 under section 115 of the Levelling-up and Regeneration Act 2023. There is an important transitional rule: if the works were substantially completed before 25 April 2024, the old four-year limit still applies to them. So an extension finished in 2021 can already be immune, while an identical extension finished in 2025 will not be immune until 2035. Immunity is not automatic paperwork — it is a defence, and you still need evidence to prove the date. Deliberate concealment of the works can also allow a council to apply for a planning enforcement order that reopens an expired time limit.

Is indemnity insurance enough for a buyer's solicitor?

Often, yes — but understand what it does. Indemnity insurance covers financial loss if the council takes enforcement action; it does not make the building lawful, and it does not prevent enforcement. It is cheap, usually a one-off premium in the low hundreds, and it is instant, which is why it is the default fix when a chain is under time pressure. The critical condition is that you must not have approached the council about the works. Any contact with the local planning authority — an informal email, a retrospective application, even a pre-application enquiry — will normally void the policy or make it unobtainable. That is why the route decision has to be made before anyone picks up the phone to the council.

What is the difference between a lawful development certificate and a retrospective application?

A lawful development certificate for an existing use or development, under section 191 of the Town and Country Planning Act 1990, asks the council to confirm that what you have built is already lawful — either because it never needed permission or because it is immune from enforcement. It is a question of fact and law, not planning merits, so the council cannot refuse it because it dislikes the design. A retrospective application, under section 73A, asks for permission you never had, and it is judged on merits exactly like any ordinary application. The certificate is the stronger document at sale because it proves lawfulness outright. The retrospective route carries real risk: if the council refuses, it has just been handed a documented breach.

Do I have to tell the buyer the extension was built without permission?

Yes. The TA6 property information form asks directly about alterations, planning permissions and building regulations approvals. Answering inaccurately, or giving a technically true answer that creates a false impression, exposes you to a misrepresentation claim after completion — long after the money has moved. Buyers routinely discover the position anyway, because surveyors compare the building to the records and solicitors search the council's planning register. Disclosing early and arriving at the enquiry with a solution already in hand is almost always the cheaper outcome: it removes the buyer's leverage to demand a retention against the price. The PlanWiser planning quiz is a fast way to work out what your position actually is before the enquiry lands.

An unauthorised extension discovered at sale is a sequencing problem more than a legal one. Establish whether it needed permission, work out which enforcement clock applies and whether it has run, then choose between the certificate, the application and the policy — in that order, and before anyone contacts the council. Done in the right sequence it is usually weeks and a few hundred pounds. Done in the wrong sequence it is a lost buyer.

Need more than the quiz?

For a specific address, in writing, by a chartered planner.

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A written assessment of your property's planning position — designations, permitted development status, and whether the works look immune. Useful evidence-gathering before you commit to a route.

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How this guide was researched

All statutory facts cited to primary legislation. Fees taken from the England householder scale in force from 1 April 2026. Practical timescales and evidence expectations drawn from local planning authority and consultancy practice. England only. Subject to change. Updated August 2026.

Sources

Tom Weighton