What you are paying to find out
A pre-application service lets you discuss a proposal with the council before making the formal application. Advice can identify relevant policies, concerns about the proposal and supporting information likely to be required. The scope depends on the service offered and the information you supply. [1][2]
A useful request is therefore a set of questions, not simply “Will this get permission?” For example: does the principle of a separate dwelling raise an objection; which aspects of the extension need changing; or what evidence is needed to assess a particular constraint? These questions give you something practical to do with the reply.
When it can be useful
Consider advice before committing to a detailed scheme where there are competing design options or a potentially significant policy issue. National policy published on 17 August 2026 supports proportionate early engagement, including where non-major proposals raise complex matters such as effects on heritage assets. It does not turn every small project into a mandatory paid pre-application exercise. [3]
For a straightforward proposal, compare the likely value of advice with the information already available from the development plan, design guidance and previous decisions. The aim is to resolve a real uncertainty, not merely add another stage.
Check the service before paying
Councils set out their own pre-application arrangements. Ealing, for example, publishes a dedicated service explaining how to seek advice. Do not assume a fee includes a meeting, site visit, specialist consultation or follow-up review unless the council's current offer says so. [4]
Before booking, record the service requested, required documents, response format and quoted charge. Ask whether your questions fall within its scope. No universal London price or guaranteed response time applies to the service described here. [2][4]
Send enough to make the advice meaningful
Prepare a clear site identification, an explanation of the existing and proposed use, and drawings proportionate to the questions. Explain important constraints and the alternatives you want considered. Advice based on an incomplete or materially different proposal is not a reliable substitute for assessment of the final application. [1]
How to use the response
Keep the written advice with your project records. Make a short schedule of each concern, the design response and any evidence still needed. Where you disagree, identify the relevant policy or evidence rather than treating the advice as a negotiation over personal preferences.
The formal application will still be assessed against the relevant policies and material considerations, including consultation responses. A positive pre-application letter is useful context, not an undertaking to grant permission. [1][2]