Searching decision data across several authorities

Finding comparable decisions across several local planning authorities is slower than it should be, because there is no single national search that returns the officer reports and decision notices you actually need. Planning decision data is published, but it is published in fragments: a national dataset of some fields, an appeal database, and around 317 separate council registers with their own search interfaces.

A search that returns useful comparables is built rather than typed. The method below is the one that survives contact with a real deadline.

What is published, and in what form

Three sources carry most of what a consultant needs.

National planning data at planning.data.gov.uk publishes structured datasets covering designations, boundaries and some application-level information, in a form you can query and download. It is strongest for constraints and weakest for the narrative content of decisions.

The Planning Inspectorate's appeal casework database carries appeal decisions with searchable fields for the authority, the procedure, the development type and the outcome, and the decision letters themselves. Appeal decisions are indicative of how inspectors have approached an issue rather than binding precedent, and they should be described that way.

Individual council registers carry the applications themselves: the forms, the drawings, the consultee responses, the officer report and the decision notice. This is where the reasoning lives, and it is the least consistently searchable of the three.

Assume from the start that you will need all three, and that the council registers will consume most of the time.

Structuring a search that returns comparables

Decide what makes a decision comparable before you search, and write it down. A vague search returns hundreds of results you then have to read.

Comparability usually rests on four or five attributes: the type of development, the scale, the constraint or policy issue in play, the setting, and sometimes the authority type. A rear extension in a conservation area is comparable with other rear extensions in conservation areas, not with extensions generally.

1. Write the comparability criteria as a short list before searching.
2. Choose five to eight authorities that share the relevant characteristic, rather than searching everywhere.
3. Search each register using development description keywords rather than address fields.
4. Restrict by decision date to a period where current policy applied.
5. Record every candidate, including ones you reject, with the reason.
6. Retrieve the officer report for each survivor, not only the decision notice.

Searching a manageable number of authorities properly beats searching all of them badly. Ten well chosen comparables with officer reports are worth more at a hearing than fifty references without them.

Filtering by description and date

Development descriptions are free text written by applicants, so keyword searching is imprecise in both directions. The same development appears as "erection of a single storey rear extension", "single storey rear extension to dwelling" and "proposed rear extension", and searching for one phrase misses the others.

Use the shortest distinctive phrase rather than the full description. Search for "rear extension" rather than the whole wording, then filter the results by reading. Where a register supports wildcard or partial matching, use it.

Date filtering matters more than it looks. Policy moves, and a decision taken under a superseded version of the National Planning Policy Framework will be met with the argument that the policy basis has changed. The Framework was reissued in December 2024 and again on 17 August 2026 with policy-coded chapters replacing paragraph numbers, so a comparable decided before those dates needs to be cited with care about which edition applied.

Local plan adoption dates matter in the same way. A decision made under a plan that has since been replaced is weaker evidence than one made under the current plan.

Pull the officer report, not just the notice

A decision notice tells you the outcome and the conditions. The officer report tells you why, and the why is the part you are citing.

Download the report as a file and keep it. Council registers reorganise, documents move, and a link that worked when the statement was written may not work when the case is heard. Save the report, the decision notice and a screenshot of the register entry showing the reference and the decision date.

Read the report for three things: how the officer framed the policy test, what evidence was treated as sufficient, and what weight was given to the objections. A comparable that reached the outcome you want for reasons that do not apply to your site is not a comparable.

Consultee responses are worth retrieving where the issue is technical. A highways response, a conservation officer's comments or a lead local flood authority position often states an expectation more clearly than the officer report does. That is also true when checking whether a particular body was engaged at all, as in checking whether the strategic road network is engaged.

Recording each comparable for citation

Keep a single table with one row per comparable, holding the authority, the application reference, the site address, the date of decision, the description of development, the outcome, the specific point it supports and the file name of the saved report.

That table becomes the appendix. It also stops the common failure where a comparable is cited in the text and nobody can find it a month later.

Where the comparable is an appeal decision, record the appeal reference and the procedure used. Written representations, hearings and inquiries carry different depths of evidence, and an inspector will read a decision from an inquiry differently from one on written representations.

A similar discipline applies to any published dataset you rely on, including monitoring figures, where the base date and version matter as much as the number, as described in finding housing land supply and delivery test figures.

The limits of automated searching

Automated collection across registers is constrained in ways worth knowing before you invest time in it.

Register interfaces differ, many require session handling, and several publish documents only as scanned PDFs without a text layer. Development descriptions are inconsistent. Some authorities remove documents after a period. And terms of use vary, so check what an authority permits before running any bulk retrieval against its register.

The national dataset avoids some of those problems but does not carry officer reports, which is the content you need most. So the honest position is that this remains a partly manual exercise, and the time should be budgeted rather than wished away.

The structured national data is still excellent for the constraint side of a search. Use it to identify which sites sit in a conservation area, a flood zone or a designated area, then go to the registers for the decisions on those sites.

Turning results into usable evidence

Cite comparables for a specific proposition, not as general support. A sentence saying that three authorities have accepted a particular form of evidence, with the references, is useful. A list of twelve references under a heading is not.

Put the point first and the reference second. Say what the officer accepted, then give the authority and reference, then move on. Your Planning Statement is easier to write and far easier to read when each comparable earns its place in a single sentence.

And be straight about the ones that went the other way. An officer who finds a contrary decision you did not mention will discount everything else you cited. Naming it and distinguishing it costs two sentences and buys the credibility the rest of the argument needs.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it.

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