Checking a planning document for contradictions after edits

A planning document consistency check is the last half hour of work before submission, and it catches the errors that make a case officer distrust everything else in the bundle. Site area, unit numbers, floorspace, parking counts and the description of development have to agree across every document and drawing. When they do not, the officer stops reading for merit and starts reading for mistakes.

Edits cause this. A drawing revision at the eleventh hour, a section regenerated after a client comment, a planning statement written against the earlier layout.

How contradictions appear

Three mechanisms account for nearly all of them.

The first is sequencing. The supporting statements are written against revision C of the drawings and the application goes in with revision E, because the architect resolved a stair core in the meantime.

The second is partial editing. Someone updates the unit count in the planning statement's opening paragraph and misses the same figure in the policy compliance section, in the table, and in the affordable housing paragraph.

The third is source confusion. Gross internal area and gross external area get used interchangeably, or the red line site area gets quoted where the net developable area was meant.

Where sections of a report are regenerated after an edit, the risk goes up rather than down, because the new section is internally coherent and silently different from the one before it. Our note on version control when report sections are regenerated sets out a way of tracking that.

The fields most likely to diverge

In rough order of how often they cause trouble:

• site area in hectares, and whether it is the application site or the wider ownership
• number of dwellings, and whether it is net or gross after any demolition
• floorspace, with the measurement basis stated
• habitable rooms or bedspaces, where a policy uses them
• parking and cycle parking numbers
• storey heights and building height in metres
• the description of development itself
• biodiversity baseline units and the percentage gain claimed
• affordable housing numbers, tenure split and percentage

The last two matter disproportionately because they are both policy tests. A biodiversity gain figure that differs between the metric output and the planning statement invites a question about which one the council should condition.

Checking figures across documents

Do it mechanically rather than by reading. Reading misses numbers because the brain accepts a familiar sentence.

1. List every document and drawing going into the application, with its revision reference.
2. Build a table with one row per quantity and one column per document.
3. Fill the table by searching each document for the figure rather than by reading it through.
4. Resolve every row where the cells disagree, by changing the documents, not the table.
5. Record the agreed figure and its source, then reissue.

Search for the units as well as the digits. Searching for "0.48" finds the number; searching for "ha" finds the places where someone wrote a site area you have forgotten about.

Thresholds deserve their own pass. Major development is triggered at 10 or more dwellings, 1,000 m2 or more of floorspace, or a site of 0.5 hectares or more, and the thresholds PlanScope uses to flag reports follow those figures, with councils' own validation lists and national policy taking precedence. A scheme that reads as 0.49 hectares in one document and 0.51 in another has two different application fees, two different consultation regimes and two different document bundles.

The description of development

This is the field that causes the most expensive mistakes, because it defines the permission. Every document that quotes it must quote it identically, including the punctuation.

Common divergences: a demolition element present in one version and absent in another, the word "up to" appearing in front of a unit number in some documents, an access described as new in one place and improved in another, and a change of use expressed by class in one document and in plain words in another.

Fix the description first, then propagate it. Treat it as a controlled string that nobody edits without changing it everywhere.

A worked site area example

Illustrative figures throughout. A site is measured by the surveyor at 0.5102 hectares. The architect's location plan rounds it to 0.51 ha. The planning statement, written earlier from a title plan, says 0.48 ha. The drainage strategy uses 5,102 m2 and the biodiversity metric uses 0.49 ha because the assessor excluded the adopted verge.

Four documents, four numbers, and every one of them defensible in isolation. The officer sees an applicant who does not know how big the site is.

The resolution is not to force all four to match. It is to state one application site area, 0.5102 ha, in every document, and where a document properly uses a different figure, to label it: net developable area, or habitat assessment area excluding highway land. One number, with named exceptions.

A reconciliation table

Carry a short table at the front of the planning statement, or as an appendix. It is unusual and officers appreciate it.

The table does two things. It forces the reconciliation, and it tells the officer which document governs each figure, which removes an entire category of validation query. Where a figure is not yet known at submission, say so rather than inventing a number. Drafts that insert a [TO BE CONFIRMED] marker are doing the right thing, and the marker has to be resolved before the document goes anywhere near the portal.

The final pass before submission

Allow an hour and do it in this order.

Check the revision references first: every drawing listed in every document should be the revision you are actually submitting. Then run the figure table. Then read the description of development in each document side by side. Then check the policy references, because a statement written against an older edition of the National Planning Policy Framework will cite paragraph numbers rather than the policy codes used in the current edition published on 17 August 2026.

Last, read the first and last paragraph of each document consecutively. Contradictions between an opening summary and a closing position are common and embarrassing.

Where a specialist report is involved, the specialist owns their figures. Do not edit a consultant's numbers to match your statement. Ask them to reissue, and if they will not, state in the planning statement which figure governs and why. The professional directory is the route for getting a draft reviewed and signed off by someone who will stand behind the content.

Our note on why planning applications are returned as invalid covers the validation failures that this exercise prevents, and what drafts get right about structure and wrong about evidence explains where the figures have to come from in the first place.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.