You're about to spend £300,000–£700,000 on a property — partly because of what you think you'll be able to do to it. A loft conversion. A rear extension. Maybe both. But on this street, those exact plans may have already been refused — multiple times. And if they have, you won't find out until after you've bought.
We've analysed 2,590,000+ planning decisions across 240 UK councils. The data shows massive variation in what gets approved from one street to the next — even within the same council area. Two identical extension proposals on streets half a mile apart can have completely different outcomes. On some streets, rear extensions are approved almost every time. On others, they're refused repeatedly — same council, same policies, different outcomes. If you're buying on one of those streets, the decision has already been made before you even instruct an architect. The planning history of a property and its neighbours is the single best predictor of what you'll be allowed to do after you buy.
Why Planning History Matters More Than You Think
Estate agents will tell you a property has "potential." They'll mention scope for extension, subject to planning. What they won't tell you is that three previous owners have already tried to extend — and been refused every time.
Here's what unchecked planning history can cost you:
| Scenario | Typical cost |
|---|---|
| Architect drawings for a refused application | £1,500–£3,000 |
| Planning application fee (wasted on refusal) | £258 |
| Structural engineer report (wasted) | £500–£1,000 |
| Redesign and resubmit after refusal | £2,000–£4,000 |
| Appeal costs if you contest the refusal | £3,000–£8,000 |
| Overpaying for a property you can't improve | £10,000–£50,000+ |
The last line is the one most buyers miss entirely. If you're paying a premium because you plan to extend, and the planning history shows that extensions on that street get refused, you've overpaid for the house as it stands.
See what's actually been approved and refused on your street →
What to Check — and Where
There are three layers of planning history that matter when you're buying. Most buyers check none of them. Smart buyers check all three.
1. The property itself
Has the property had previous planning applications? Were they approved or refused? This is the most basic check and the one your solicitor's local search should partially cover. But local searches only flag applications on the property — they don't tell you what happened to identical proposals nearby.
What to look for on the property itself:
- Previous refusals. A refusal on record means a planning officer has already decided that something doesn't work on this property. If the reason was "harm to the conservation area" or "out of keeping with the streetscene," that reason likely still applies.
- Conditions on previous approvals. Sometimes approvals come with conditions that restrict future development — like removing permitted development rights. This means work that would normally be allowed without permission suddenly requires a full application.
- Enforcement notices. If the property has an enforcement history, previous owners may have built without permission. You could inherit the problem.
2. The immediate street
This is where most buyers miss critical information. What's been approved or refused on neighbouring properties is directly relevant to what you'll be allowed to do. Planning decisions create precedent. If your neighbour's rear extension was approved, yours is more likely to succeed. If three applications for loft conversions on your street were refused, yours probably will be too.
Precedent cuts both ways. If every house on the street has been extended and yours hasn't, you're in a strong position — the principle is established. But if the street is untouched and your proposal would be the first, expect much harder scrutiny. Planning officers protect the character of streets that haven't yet been altered.
3. The wider area — council approval rates
Different councils refuse at very different rates. Some approve over 90% of householder applications. Others refuse more than 1 in 4. If you're buying in a high-refusal council area, your plans need to account for that reality.
| Council type | Typical approval rate | What it means for buyers |
|---|---|---|
| High-approval council (90%+) | 90–95% | Most reasonable applications succeed |
| Average council | 83–89% | Standard scrutiny, precedent matters |
| Strict council (below 80%) | 70–80% | Design quality and precedent are critical |
| Conservation-heavy area | 65–78% | Extra restrictions, materials stipulations, possible Article 4 directions |
The difference between buying in a 93% approval area and a 74% approval area is enormous. In the first, your extension is almost certainly going through. In the second, you're rolling dice — and the professional fees are the same either way.
See exactly what's been approved and refused near any property
Before you make an offer, check the real decisions that will determine what you can build. Approval rates, refusal patterns, and comparable decisions for your postcode — not guesswork.
Check Your Postcode — Free →How to Actually Check Planning History
There are several ways to check, ranging from free-but-slow to instant.
Option 1: Council planning portal (free, slow)
Every UK council publishes planning decisions on their online planning portal. You can search by address, postcode, or application reference. The problem: there are 300+ councils, each with a different portal, different search interface, and different levels of data quality. Finding and interpreting results takes time — and comparing across streets or areas means repeating the process for every address.
Option 2: PlanningLens (free check, instant)
PlanningLens aggregates planning decisions from 240 councils into a single postcode search. Enter a postcode and immediately see the approval rate, refusal patterns, and real decisions nearby. The free check gives you the headline picture. The Planning Permission Check (£19) gives you the full breakdown with 60+ comparable decisions, refusal reasons, and what the patterns mean for your specific property type.
Option 3: Your solicitor's local search
The local authority search that your solicitor orders will flag planning applications on the property itself, plus any nearby developments that might affect it. But local searches are limited — they typically only cover the specific property, not the street-level precedent that matters most. And they arrive weeks into the conveyancing process, often after you've already committed emotionally and financially.
The best approach: check planning history before you make an offer, not during conveyancing. By the time your solicitor's search comes back, you've already paid for surveys, instructed a mortgage, and possibly exchanged on your own property. That's too late to discover the extension you planned isn't going to happen.
Five Red Flags in Planning History
When you're reviewing planning history near a property, these are the warning signs that should make you pause — or renegotiate your offer:
- Repeated refusals on the same property. If the property has been refused twice for the same type of work, the planning authority has made its position clear. Resubmitting a similar scheme is unlikely to succeed without a material change in circumstances.
- Refusals on neighbouring properties for work you're planning. If three houses on the street have been refused for loft conversions, your loft conversion faces the same objections. The precedent works against you.
- Conservation area designation. Conservation areas impose additional restrictions on materials, design, and sometimes even the principle of extension. Permitted development rights are often reduced. Check whether the property falls within one.
- Article 4 directions. These remove specific permitted development rights from a property or area. They mean work that would normally be allowed without permission requires a full application — adding cost, delay, and the risk of refusal.
- No planning history on the street at all. An untouched street isn't necessarily good news if you're planning to extend. It means there's no established precedent, and your application will be the test case. Planning officers are more cautious with first-of-type applications.
See the decisions that will determine what you're allowed to build →
Five Green Flags in Planning History
Conversely, these are the signs that planning history is on your side:
- The exact work you want has been approved on the street. This is the gold standard. If three neighbours have rear extensions and you want one too, the principle is established. Your architect can reference those approvals directly.
- A high council approval rate for your project type. If the council approves 90%+ of rear extensions, the odds are firmly in your favour. Design quality still matters, but the baseline is permissive.
- Recent approvals (last 2-3 years). Planning policy evolves. A recent approval is stronger precedent than one from 2012. It shows the current planning team supports that type of development.
- An existing approval on the property itself. Even if the previous owner didn't build it, an unbuilt approval tells you the principle has been accepted. You may be able to implement it, or use it as a baseline for a revised scheme.
- Mix of extensions on the street. A street where houses have been extended in various ways signals a permissive planning environment. It's much harder for officers to refuse your proposal on character grounds when the street character already includes extensions.
The planning history already exists. You just haven't checked it.
Every planning decision near a property tells you something about what you'll be allowed to do after you buy. Check before you offer — not after you've committed.
Check Your Postcode — Free →When Planning History Should Change Your Offer
If you're buying a property partly for its development potential, the planning history should directly inform your offer price. Here's when to adjust:
Reduce your offer if the planning history shows refusals for the type of work you're planning, if the property is in a conservation area with restrictive policies, or if the council has a below-average approval rate for your project type. The "potential" the estate agent is selling may not exist.
Hold firm on your offer if the street has strong precedent for the work you want, the council is permissive, and ideally if there's an existing approval on the property. In that case, the development potential is real and priced into the market for good reason.
Walk away if the property has been refused multiple times for the work that makes it worth buying, or if an Article 4 direction has removed the permitted development rights you were counting on. No house is worth its asking price if the plan that justified the price can't happen.
The Bottom Line
Planning history is the most overlooked piece of due diligence in the UK property market. Buyers spend thousands on surveys, valuations, and legal searches — but rarely spend ten minutes checking what's actually been approved and refused on the street they're about to buy into.
The cost of checking: nothing. The cost of not checking: potentially tens of thousands in wasted fees, stalled plans, or overpaying for a property you can't improve the way you intended.
Check before you offer. Not after you complete.
See what's really been happening near a property
Real planning decisions from 2,590,000+ applications across 240 UK councils. See what gets approved and what gets refused on your street — takes 10 seconds.
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