Comparable planning decisions in the local cluster are among the most powerful tools in any planning consultant's armoury. A well-researched set of precedents can reframe a site's planning prospects entirely. This guide explains how to find them, what to look for, and how to use them effectively in your advice.
A planning cluster is the set of applications within a defined radius or postcode area around your site. The cluster shows you how the planning authority has historically approached similar proposals — what it has approved, what it has refused, and crucially, what the officer's reasoning was in each case.
A cluster analysis is not just a count of approvals and refusals. The value is in the officer wording — the specific language used to justify each decision. That language reveals the policy interpretation that is being applied, the weight being given to specific considerations, and the arguments that have worked in the past.
Standard planning portal keyword searches return applications registered at the target address. They do not systematically map the surrounding cluster. To build a genuine cluster picture you need to query by postcode sector, by grid reference radius, or by committee area — none of which the standard portal search interface supports directly.
Withdrawn applications within the cluster are even harder to find. An applicant who withdrew before a decision may have found the same problem you are now trying to solve — making their experience highly relevant to your advice. But it will not surface in any standard keyword search.
The most effective use of cluster data is to build a precedent argument that directly addresses the council's likely grounds for refusal. If the council tends to refuse agricultural dwelling applications on the basis that the functional need is not demonstrated, find the applications in the cluster where that argument was successfully rebutted — and extract the officer's own wording acknowledging the sufficient need.
Approved comparable decisions are persuasive. But refused comparables are equally valuable — they tell you the threshold the council is applying, the specific policy interpretation in play, and the language that does not work. Understanding what has failed in the cluster is as important as understanding what has succeeded.
Committee officer reports are the single richest source of planning intelligence available on any site — and they are almost entirely inaccessible to standard searches. Officer reports set out the full reasoning behind a decision: the policy context, the officer's assessment of each material consideration, the weight given to objections, and the conditions imposed. They are the difference between knowing that a barn conversion was approved and understanding why.
Officer reports are filed as PDFs attached to committee agenda packs. They are not indexed by portal search engines. Retrieving them requires direct access to the committee archive, which varies in format and accessibility across councils.
Sites near LPA boundaries — particularly in AONB areas, National Park edges, and the England-Wales border — require cluster analysis across multiple systems. The relevant comparable decisions may fall under a different authority entirely. A barn conversion approved by Herefordshire Council is directly relevant to a similar proposal in neighbouring Monmouthshire — but the two portals are entirely separate and neither cross-references the other.
Planning Decoder maps every comparable application in the cluster — approved, refused and withdrawn — with full officer wording extracted from committee archives. Delivered as a professional report you use directly in your advice.
Commission a cluster analysis →