Applying for Planning Permission: A Step by Step Guide

Step one: establish whether you actually need it

Before spending anything, check permitted development. Many rear and side extensions fall within it, and where they do you can apply for a lawful development certificate instead, which confirms in writing that permission is not required.

That certificate matters at sale. Solicitors ask for evidence, and a certificate is far easier to produce years later than a conversation with a planning officer nobody wrote down.

Step two: pre-application advice

Most Kent authorities offer a paid pre-application service, typically £100 to £400 for a householder scheme. You submit sketch proposals and a planning officer gives a written view.

It is optional, and it is usually worth it where the scheme is finely balanced: a conservation area, a large two storey addition, anything close to a boundary, or a design that departs from the street pattern. It is rarely worth it for a modest rear extension in an unremarkable street.

Step three: drawings and documents

A householder application is refused or delayed more often for incomplete documents than for bad design. The validation checklist is published by each council and is not negotiable.

Location plan at 1:1250 with the site edged red · Block or site plan at 1:500 or 1:200 · Existing and proposed elevations and floor plans, usually at 1:100 or 1:50 · Design and access statement where the property is listed or in a conservation area · Ownership certificate and, where relevant, agricultural holdings certificate · The correct fee

Step four: submission, timings and fees

Applications go through the Planning Portal. The council has a target of eight weeks for a householder decision from the date the application is validated, and validation itself can take one to three weeks if anything is missing.

Householder planning: indicative fees and timescales (England, 2026). Stage | Typical cost | Typical duration. Pre-application advice — £100 – £400 — 3 – 6 weeks; Architectural drawings — £1,500 – £4,000 — 3 – 6 weeks; Householder application fee — £258 — Paid on submission; Lawful development certificate — £129 — 6 – 8 weeks; Validation — Included — 1 – 3 weeks; Consultation period — Included — 21 days; Determination — Included — 8 weeks from validation; Discharging conditions — £145 per request — 4 – 8 weeks; Appeal (written representations) — Free to lodge — 3 – 6 months

Step five: consultation and objections

Neighbours are notified and have twenty-one days to comment. An objection is not a veto: the officer weighs comments against planning policy, and objections about loss of view, competition or building work noise carry no planning weight.

Material considerations that do carry weight include overlooking and loss of privacy, loss of light, overbearing scale, harm to the character of a conservation area, highway safety and impact on protected trees. Speaking to neighbours before you submit, with drawings in hand, resolves more objections than any planning statement.

Step six: decision, conditions and what comes next

Most householder applications are decided under delegated powers by an officer rather than by committee. Approval usually arrives with conditions attached: matching materials, obscure glazing to a flank window, restricted working hours, or details to be submitted before work starts.

Permission lasts three years and you must begin within that period. If refused, you can appeal to the Planning Inspectorate within twelve weeks, or more commonly submit a revised scheme, which is free within twelve months of the first decision on the same site.

Planning permission is not building regulations

They are separate approvals with separate fees and separate inspectors. Planning governs whether the building may exist in that form and place; building regulations govern whether it is structurally sound, insulated, ventilated and safe. You need both, and having one does not imply the other.

Frequently asked questions

How long does planning permission take in Kent?

Budget three to four months from instructing a designer to holding a decision: several weeks for drawings, up to three weeks for validation and the statutory eight weeks for determination.

Can a neighbour stop my extension?

No. They can object, and the council must consider material planning matters raised, but objections based on view, property value or personal disagreement carry no weight in the decision.

What happens if I build without permission?

The council can serve an enforcement notice requiring removal, generally within four years for operational development. Retrospective applications are possible but you are negotiating from a weak position, and the property becomes hard to sell in the meantime.

Do I need an architect?

Not legally. You need drawings that meet the validation checklist and a design that will be supported. An architect or architectural technologist is usually the cheapest route to both.