Navigating planning permission can feel like solving a puzzle: it takes time, requires persistence and can at times be confusing. Whether your job is large or small, a new build or an extension, understanding the timelines is crucial. At Armstrong Simmonds Architects, we guide clients through the planning process so that timelines are clear and understood. In this article, we’ll give some general insight into how long a planning permission typically lasts.
The Standard Duration: Three Years for Most Permissions
In the UK, planning permission is generally valid for three years from the date it’s granted by your local planning authority (LPA). However, this can vary depending on application type or conditions attached to an approval. For householder development outside of a conservation area, a three year period is expected. That gives you a three-year window to commence your development – not to complete it, but to start it.
Why do applications need a time limit? The main aim is to keep approved schemes moving rather than sitting idle while local policies evolve and change. For larger schemes, it also discourages land banking where owners wait for land value to rise before deciding to build.
Imagine you’ve just received approval to develop your dream home… The clock starts ticking the moment the decision notice lands. So, if you don’t begin work within those three years, the permission expires and you’ll need to reapply – potentially facing updated regulations, higher fees and fresh neighbour consultations.
It’s worth noting that your LPA can set a shorter or longer timeframe through a planning condition. This is relatively rare for standard applications, but it happens more often in conservation areas or on complex sites, so always read your decision notice carefully.
What Counts as 'Commencing' Your Development?
A question we hear often is: what exactly does ‘starting work’ mean? It isn’t as simple as picking up a hammer on day one. To implement your permission and stop it expiring, you need to carry out a ‘material operation’ – work that genuinely forms part of the approved development.
Section 56 of the Town and Country Planning Act 1990 sets out what constitutes a material operation for the purposes of implementing a planning permission. However — and this is particularly important to note — planning legislation and case law can change over time. What constitutes a material operation at the time of writing may not necessarily be treated in the same way in the future.
There can also be uncertainty or ambiguity in how the legislation is interpreted and applied, particularly where the circumstances of a particular site or development are not straightforward. As such, caution should always be exercised when relying on a particular type of work to demonstrate that a planning permission has been lawfully implemented.
Before you begin any work, you also need to make sure every pre-commencement conditions have also been discharged. Watch this space! We will be writing a blog soon to explain what conditions are and how they work in general.
What Happens If Your Permission Expires?
If the three-year limit (or an adjusted one) passes without lawful commencement, your permission lapses. Reapplying is the usual way forward, but London’s planning landscape moves quickly – updated local plan policies, heritage protections, or sustainability requirements could all affect a fresh application. This might call for new surveys, higher fees, or changes to meet current standards, which can push a project back significantly.
Can you extend or renew planning permission? In most cases, no. The route that once allowed certain permissions to be extended was withdrawn some years ago, and for any permission granted after 1 October 2010 there is no mechanism to extend the time limit once it has passed. If your permission is approaching expiry and you’re not ready to start, speak to your project team early.
Our advice? Map the critical path early and keep a close eye on the dates. We’ve helped clients avoid expiry by programming condition discharge, building control, and tendering well before the final year.
Does the Time Period Depend on the London Borough?
The normal statutory commencement period is set nationally under the Town and Country Planning Act 1990, rather than by each borough. For most planning permissions, the permission must be begun within 3 years of the date the permission is granted, unless the permission specifies a different period.
Top Tips for Making the Most of Your Permission
- Plan ahead. Use the approval period wisely. Secure funding, appoint contractors, obtain building regulations approval, and discharge pre-commencement conditions early. Don’t leave implementation to the final months.
- Monitor key dates. Set calendar reminders for the milestones that matter: condition discharge deadlines, and the final date to commence.
- Seek professional guidance. Experienced architectural support reduces the risk of expiry. We understand what local authorities expect and can advise on the most efficient path forward.
- Consider party walls. If your development affects adjoining properties, party wall agreements take time to arrange. Start the process well before your intended commencement date.
Transforming your London home shouldn’t be held back by timelines. With our collaborative, concept-to-completion approach, Armstrong Simmonds Architects turns potential hurdles into steady progress.
Ready to discuss your project? Get in touch with Armstrong Simmonds Architects to arrange a consultation.
