How much does planning permission really cost in Southwark?

Most homeowners in Southwark start by Googling the application fee. That's the easy part. What they don't realise is that the fee is often the smallest — and simplest — part of what planning permission actually costs. If you'd rather not piece this together yourself, WhatCanIBuild can show you what's actually at stake for your specific address before you spend a penny.

The £258 fee is just the beginning

For a standard householder application — a rear extension, a loft conversion, that kind of thing — the application fee is £258. That's set nationally. On top of that, Planning Portal adds a service charge of £75.83 + VAT for applications submitted online that attract a fee over £100. So before you've spoken to an architect, drawn up plans, or hired a planning consultant, you're already past £300.

Most homeowners don't realise those professional costs can dwarf the application fee itself. Architectural drawings, planning statements, heritage impact assessments — depending on what your property requires, these can add hundreds or thousands to the bill. And whether your property requires any of them depends on things you probably haven't checked yet.

Southwark isn't one place — it's dozens of micro-planning zones

Southwark has an unusually high concentration of conservation areas. Peckham, Dulwich, Bermondsey, parts of SE1 along the Thames — the borough is riddled with designations that most homeowners only discover mid-application. If your property sits within one, the rules about what you can do — and what you need to formally apply for — can be completely different from a street two minutes away.

Then there are Article 4 directions, which can strip away permitted development rights you thought you had. Flood zone considerations near the Thames. Strategic view corridors. Listed buildings that trigger separate consent requirements with no application fee, but significant professional costs to navigate correctly.

The uncomfortable truth is that two houses on the same street in SE15 or SE22 can face entirely different planning requirements. Your neighbour got their extension approved last year — but were they in the same flood zone as you? Did they have the same permitted development restrictions? It depends on your property, not just your postcode.

What a refusal actually costs you

Here's the part that catches people out. If Southwark's typical decision window is around 8 weeks, and your application is refused, you don't get the fee back. You can reapply or appeal — but both take time and money. A refused application that could have been avoided with better upfront information can set a project back by months and cost significantly more than the original fee.

Approval isn't guaranteed just because your neighbour did something similar. What got approved on your street, and what got refused — and crucially, why — is the kind of intelligence that changes how you approach your application. The best way to see what's actually been approved for similar projects near your property is to use WhatCanIBuild, which pulls in local decision data so you're not going in blind.

What you actually need to know before you apply

The fee is public information. What isn't public — at least not in any usable form — is how your specific combination of constraints affects your chances, what similar projects on your street have been approved or knocked back, and whether your project is likely to sail through or hit unexpected requirements.

WhatCanIBuild gives you that picture for your address. Not generic guidance — your property, your street, your Southwark.