How Long Does Planning Permission Take in London? (2026 Guide)

Planning permission in London typically takes 8 weeks for a standard householder application, though it can take longer for complex projects or in certain boroughs. Understanding the planning timeline is essential for scheduling your loft conversion, house extension or renovation project. At LCCL Construction, we handle all planning applications as part of our design and build service and have extensive experience working with planning authorities across London and Hertfordshire.

How Long Does Planning Permission Take in London? (2026 Guide)

Not sure whether your project needs planning permission? Enter your postcode and tick what you want to build — we look up the conservation areas, Article 4 directions and listed buildings for you, and you see which parts are permitted development and the from-price for each. Lawful Development Certificate included on every permitted development job.

Planning check

Standard Planning Permission Timeline

A standard householder planning application in London has a statutory determination period of 8 weeks from the date the application is validated by the local planning authority. Validation itself can take 1 to 2 weeks after submission while the council checks all required documents are included. In practice, many London boroughs are under pressure and may take slightly longer than 8 weeks, particularly for applications that receive neighbour objections or require additional information. If the council does not decide within the statutory period, you can appeal to the Planning Inspectorate, though this adds significant additional time.

Factors That Affect Planning Timescales

Several factors can extend the planning timeline. Conservation areas require additional scrutiny and consultation, often adding 2 to 4 weeks. Neighbour objections trigger additional assessment by the planning officer. Requests for additional information or amended plans pause the determination clock. Listed building consent is a separate application that runs in parallel and can take 8 to 13 weeks. Complex projects involving significant design considerations or departures from local policy may be referred to the planning committee, which meets monthly, adding weeks to the timeline. Some London boroughs are consistently faster than others depending on staffing levels and workload.

Permitted Development: A Faster Alternative

Many loft conversions and single storey house extensions in London can be built under permitted development rights without needing planning permission at all. This completely eliminates the 8-week planning wait. Instead, you can apply for a Certificate of Lawfulness which confirms your project is lawful under permitted development rules. This typically takes 6 to 8 weeks but your project can start before it is issued if you are confident the development is permitted. LCCL Construction assesses every project for permitted development eligibility and recommends the fastest route.

Prior Approval for Larger Extensions

For larger single storey rear extensions between 4 and 8 metres on detached houses or 3 and 6 metres on semi-detached and terraced houses, a prior approval application is required. This is a lighter-touch process where the council consults neighbours and considers the impact on their amenity. The council has 42 days to respond. If they do not respond within 42 days, the development is deemed approved. This is faster than full planning permission and has a higher likelihood of approval since the principle of development is already established under permitted development.

How LCCL Construction Manages Planning Applications

Can it be done under permitted development?

Before you plan for an eight-week application, check whether you need one at all. On a house outside a conservation area or Article 4 street, a rear dormer, a hip-to-gable or L-shaped loft and a single-storey rear extension within 3 m (4 m detached) are permitted development: no planning application, no committee, no neighbour consultation — just a Lawful Development Certificate, which has the same eight-week decision period but is a check against fixed rules rather than a judgement, and which we apply for on every permitted development project. See our permitted development projects page for every product with its from-price and the checks we run before we confirm a project qualifies. Not sure whether your project needs a planning application?

Check if you need planning permission

LCCL Construction prepares and submits all planning applications as part of our design and build service. Our architects produce detailed drawings that meet each borough's submission requirements, reducing the risk of validation delays. We have working relationships with planning departments across London and Hertfordshire and understand their specific policies and preferences. We manage all correspondence with the planning authority, respond to requests for additional information promptly, and keep you informed at every stage. Our experience means we can usually advise upfront on the likelihood of approval and any potential issues. Contact us on 020 8037 7332, email info@lcclconstruction.co.uk, or book at lcclconstruction.co.uk/booking-calendar/free-consultation-call.