How Long Does It Take to Get Planning Permission? (UK Reality)
In the UK, planning permission typically takes 8 weeks from validation for standard householder applications like extensions or loft conversions, and 13 weeks for larger or more complex developments. In practice, once you account for validation checks and possible amendments, most applicants should budget 9–12 weeks from submission to decision.
The rest of this guide covers why the real timeline rarely lands on a clean 8 weeks, what’s actually happening behind the scenes while you wait, and what you can do if your application starts to drag.
What’s the standard timeline for planning permission?
There’s a statutory framework behind the “8 weeks” figure you’ll see everywhere, and it’s worth understanding properly because it’s not quite as simple as it sounds.
- 8 weeks -householder applications and most minor developments (extensions, loft conversions, garages, dormers)
- 13 weeks -major developments (new-build housing, larger commercial schemes)
- 16 weeks -applications requiring a formal Environmental Impact Assessment
(Source: GOV.UK -Determining a planning application)
Here’s the part that catches most people out: that clock doesn’t start the moment you hit submit. It starts once your application is validated -meaning the council has checked your drawings, forms, and fee, and confirmed everything’s in order. If anything’s missing, the clock doesn’t start until you’ve fixed it.
So if you’re asking how long for planning permission from the moment you actually send your application off, you need to add validation time on top of the statutory period. For a typical householder project, that usually means somewhere between 1 and 3 extra weeks before the “official” 8 weeks even begins -this is typical practice rather than a fixed statutory figure, and it varies by council.
If you want the fuller picture of what planning permission covers and when you need it, our planning permission guide walks through that from the start.
Why do planning applications often take longer than 8 weeks?
If you’ve spoken to anyone who’s actually been through the process, you’ve probably noticed nobody says “yep, exactly 8 weeks.” There’s a reason for that, and it’s not just bad luck.
Validation problems are the single biggest avoidable delay. A missing ownership certificate, a location plan that doesn’t match the drawings, or an incorrect fee will bounce your application back before the statutory clock even starts. This is entirely within your control and entirely preventable with a properly prepared submission.
Neighbour consultation adds structural time. Once validated, neighbouring properties are notified and typically given 21 days to comment. This runs concurrently with the assessment, but it’s a fixed minimum window the council can’t skip, regardless of how straightforward your project is.
Case officer workload varies enormously by council. Some planning departments face real capacity pressure, and a backlog on their desk translates directly into a longer wait on yours.
Location matters more than most people realise. If your project falls in a conservation area, involves a listed building, or sits in a borough with a heavier planning workload, expect the process to run longer than the standard target.
Nationally, only a portion of applications are decided within the original statutory period -a meaningful share get there via an agreed Extension of Time instead, which still counts as “on time” in official statistics but isn’t the same as hitting the original 8-week target.
What are the stages of a planning application, and how long does each take?
It helps to think of this as three overlapping phases rather than one continuous 8-week countdown.
Submission and validation
You submit your application through the Planning Portal, along with the required drawings, site plan, and any supporting documents like a design and access statement. The council then checks it for completeness. This stage typically takes 1 to 3 weeks, though it can run longer if something’s missing and you need to resubmit information.
Consultation and assessment
Once validated, your application goes live for public comment, and neighbours get 21 days to respond. In parallel, a case officer is assigned and will usually visit the site, review it against local planning policy, and consider any objections raised. If they have concerns, they may come back to you requesting amendments -and each round of changes adds time, even if it’s only a week or two per round.
The decision
Most straightforward applications are decided by the case officer under delegated authority. If your project attracts significant objections or falls into certain categories, it may instead go to a planning committee, which only meets on a fixed schedule -so if you narrowly miss a meeting date, you could be waiting several extra weeks purely because of timing, not because anything’s actually wrong with your application.
Take a recent HMO Conversion in Westminster as an example. The initial design was flawless, but a localized council validation rule required an unexpected, highly specific acoustic assessment for the party walls—a detail not explicitly flagged in standard national guidance. Waiting for a specialist, scheduling the test, and resubmitting the drawings added a 4-week delay to the validation phase alone.
Because of that specific casework, we changed our standard onboarding protocol. Today, for any multi-unit or HMO project in Westminster or Kensington, we mandate and commission that acoustic scoping during the initial sketch phase. By turning a reactive delay into a proactive asset, we ensure the council receives those documents on day one, completely eliminating that 4-week bottleneck for our subsequent clients
If your project is a specific type, the timeline can shift slightly depending on what’s typically flagged for that project type. We’ve broken each of those down separately: planning permission for a loft conversion, planning permission for a conservatory, planning permission for a garage, and planning permission for a dormer.
What happens if my application isn’t decided on time?
If week 8 comes and goes with no decision, you’re not stuck with no options.
The most common outcome is that the council will ask you to agree to an Extension of Time in writing. This isn’t necessarily a bad sign -if an officer is close to approving your application but needs a couple more weeks to finalise a condition or resolve a minor amendment, agreeing to wait is usually the more sensible route than forcing a decision.
If no extension is agreed and the statutory period genuinely lapses, you have the right to appeal on the grounds of non-determination directly to the Planning Inspectorate. This is a real option, but worth weighing carefully -an appeal takes time in its own right, and if your case officer is actively working toward an approval, jumping straight to appeal can sometimes slow things down rather than speed them up. (Source: GOV.UK -Appeal a planning decision)
If you’re already past the point of getting timely advice and have started work without the right permission in place, cover what your options look like at that stage. And if an appeal doesn’t go your way, explain what happens next.
It’s also worth checking, before any of this becomes relevant, whether you need full planning permission at all -plenty of projects fall under permitted development instead, which follows a different and often faster process entirely.
Can you speed up a planning permission decision?
Here’s where we’ll be direct: no architect or planning consultant can make a council move faster. What we can do is significantly reduce the odds that your own application is the reason for the delay.
That distinction matters, because a lot of the advice out there blurs the two. Hiring help doesn’t put your application at the front of the queue -it just means you’re less likely to trigger the validation problems, missing documents, and clarification requests that are the actual cause of most avoidable delays.
Practical steps that genuinely help:
- Get your drawings right the first time, with consistent scales and dimensions across every document
- Check the specific council’s local validation checklist, not just the national requirements
- Identify constraints early -conservation area status, listed building status, Article 4 directions -before you design, not after you submit
- Respond to case officer queries quickly; a fast reply keeps your application active rather than sitting in a queue
- Consider pre-application advice for anything genuinely complex or contentious -it adds time upfront, but it can surface objections before you’ve committed to a full submission
If you’re not sure whether your project needs planning permission or could proceed under permitted development instead, our do I need planning permission guide is a good starting point.
Want a second pair of eyes on your application before it goes in? OAS handles planning applications and drawings for homeowners across London –get in touch and we’ll tell you honestly whether your project needs full permission or falls under permitted development.
Statutory timeline at a glance
| Application type | Statutory target | Realistic total (incl. validation) |
| Householder (extension, loft, garage, dormer) | 8 weeks from validation | 9–12 weeks from submission |
| Minor development | 8 weeks from validation | 9–12 weeks from submission |
| Major development | 13 weeks from validation | Often several months, especially with committee referral |
| Environmental Impact Assessment required | 16 weeks from validation | 16+ weeks, rarely relevant to standard home projects |
Frequently asked questions
How long does planning permission take for a house extension? Most house extensions need a householder planning application, which has a statutory target of 8 weeks from validation. In practice, allow 9–12 weeks from submission once validation and any requested amendments are factored in.
How long does planning permission take for a loft conversion? If your loft conversion needs full planning permission rather than falling under permitted development, it follows the same 8-week statutory target as other householder applications, though roof-form and overlooking concerns can prompt amendments that extend this in practice.
What’s the difference between submission date and validation date? Submission is when you send your application to the council; validation is when the council confirms it’s complete and starts the statutory clock. The gap between the two -often 1 to 3 weeks -isn’t counted in the official “8 weeks,” which is why real-world timelines usually run longer than the headline figure.
How long does planning permission last once granted? Most planning permissions must be acted on within 3 years of the decision date, or they lapse and you’d need to reapply.
What happens if my council doesn’t decide within 8 weeks? The council will usually ask you to agree to an Extension of Time in writing. If no extension is agreed and the statutory period passes, you have the right to appeal to the Planning Inspectorate on the grounds of non-determination.
OAS’s take
We manage planning applications for clients across London, and the pattern we see most often isn’t dramatic -it’s small, preventable friction. A missing document. A council-specific requirement that wasn’t obvious from the national guidance. A drawing that’s technically fine but invites one clarifying question that costs two weeks to answer.
Over the past 3/4 years alone, we have successfully guided 45 properties through the planning process across the London Boroughs of Camden, Islington, and Hackney. A consistent pattern we navigate weekly is the strict conservation area restrictions in these areas; by maintaining a close working relationship with local planning officers, we regularly secure approvals for modern rear extensions and loft conversions that traditional firms often label as ‘too high-risk’
The 8-week figure is real, and plenty of applications do hit it. But we’d rather tell you honestly that the number you should actually plan around is closer to 9–12 weeks for most London projects, with conservation areas, listed buildings, and anything heading to committee pushing that further out.