Guide for architects & architectural practices

Comparable decisions and how architects use them in planning

Planning decisions are not made in isolation. Every LPA develops patterns — how it interprets character and appearance, what scale it considers acceptable in a conservation area, how it applies AONB policy to extensions and conversions. Comparable decisions are the evidence base for understanding that pattern. Finding them is the problem.

Why comparables matter more than policy

Local planning policy sets the framework. Comparable decisions reveal how the framework is applied in practice — which are often different things. An LPA that states in its Local Plan that extensions in conservation areas will be assessed on their impact on character may routinely approve extensions of a particular scale and form, or may routinely refuse them regardless of design quality.

The comparable decisions in the surrounding postcode cluster tell you which it is. They tell you what the conservation officer actually considers acceptable, what the committee has been willing to approve on appeal, and where the real policy boundary sits. This is information you cannot get from reading the Local Plan.

The most useful comparable decisions for architects are often the ones that were initially refused and then approved on appeal. The Inspector's reasoning in these cases is particularly clear about where the LPA went wrong — and where the real policy boundary sits.

What a cluster sweep retrieves that a portal search cannot

A standard planning portal search returns applications for a specific address and, at best, a list of recent applications in the surrounding area filtered by what the portal's public interface is designed to show. This is not a cluster analysis. A proper cluster sweep retrieves every application — approved, refused, withdrawn, appealed — across the full postcode cluster, including applications that may have been withdrawn before decision, decided under a predecessor authority, or held in legacy systems behind portals that block automated access.

The difference in what you find is significant. Withdrawn applications, in particular, are almost entirely invisible to standard portal searches. An application that was withdrawn five weeks before the committee's decision — because the applicant knew it was going to be refused — tells you exactly where the policy boundary sits without a formal refusal on the public record.

How to use comparable officer wording in a pre-application submission

Officer reports are the richest source of comparable reasoning in the planning system. They articulate how a specific case officer or the LPA generally interpreted the policy tests applied to a specific design on a specific site. When a cluster sweep retrieves officer wording from comparable consents, that wording can be cited directly in a pre-application submission or in a design and access statement.

The most effective use of comparable officer wording is to show the case officer that a specific design approach has already been approved under the same policy framework on a comparable site. This shifts the conversation from “is this acceptable?” to “here is the precedent that shows it is.”

On a recent Denbighshire AONB commission, officer wording from two comparable consents within 800m was directly usable as precedent argument in the pre-application submission. The comparable consents were only findable because the portal required proprietary bypass — standard searches stopped at the DNS level.

Appeals — the most underused source of comparable precedent

Planning appeal decisions are published by the Planning Inspectorate and are theoretically accessible. In practice, finding the relevant appeal decisions for a specific policy question in a specific area requires searching across multiple systems, cross-referencing decision notices with appeal records, and reading a substantial volume of material to find the relevant reasoning.

A cluster analysis that includes appeal outcomes — particularly for the specific policy tests most likely to be applied to a given scheme — is the most direct way to understand where the LPA's decision-making has been overturned and why. Inspectors are consistent: if a comparable scheme was approved on appeal on a specific policy ground, that reasoning applies to your scheme too.

The portals that block standard searches

Not all UK councils use the same planning portal software. Some run on Civica Portal 360, which blocks all automated access at DNS level. Others run on legacy systems that were implemented before the current national standards. Pre-merger councils — whose planning records predate reorganisation — may hold their historical records in systems entirely separate from the current portal.

If the subject site or the most relevant comparable sites are in a council that runs on a portal that blocks automated access, standard cluster analysis is impossible. This includes a significant number of Welsh councils, some National Park Authorities, and councils with legacy pre-portal systems. We engineer past these barriers. Most search tools do not.
Get comparable decisions for your next site

We sweep 1,000+ planning records across the postcode cluster — approved, refused, withdrawn and appealed. Officer wording extracted for the most relevant comparables. Delivered in 48 hours.

Commission a cluster analysis →
£149–£249 · 48hr turnaround · any UK council · every portal

Related guides for architects

← Back to all guides