Why an AI draft flags a missing site fact

When a PlanScope draft reaches a fact it cannot establish, it inserts a "[TO BE CONFIRMED]" marker rather than filling the gap. That is deliberate. The alternative, which is what an unconstrained text generator does, is to produce a plausible number: a floor level, a site area, a distance to the nearest listed building. A plausible number in a planning statement is worse than a blank, because nobody checks it and the case officer relies on it.

So the flags are the point rather than a shortcoming. The question for anyone using an ai draft missing site data marker is which category the gap falls into, because some close in five minutes and some need a survey.

What the marker means

A flag records that the document needs a specific fact, states where it belongs, and leaves the surrounding argument intact so the structure and the policy analysis survive.

It does not mean the drafting failed. It means the fact is not derivable from the inputs given: a postcode, a property outline, a photograph and a set of answers about the project. Nothing in that set contains a measured level or a title number.

Two things follow for how you work. Fill the flags with searched or surveyed facts rather than deleting the sentence around them, because the sentence is usually there to answer a policy test. And treat the list of flags as a scope document for what the application still needs.

What a location can establish

Constraint data is positional, which is why it can be checked automatically. PlanScope tests the site against Environment Agency flood data, Historic England listed building and conservation area records, and Natural England designations, and feeds the results into its recommendation engine.

That covers a useful set of facts.

• Flood zone, and whether the site falls in Zone 2 or 3.
• Whether the site contains or sits near a listed building, with its grade.
• Whether it falls inside a conservation area boundary.
• Whether a statutory nature designation is present.
• Which local planning authority the site sits in.

Those are the inferable facts, and they are the ones that drive the first pass at which reports a project needs. The public datasets behind them are open, so you can verify any of them yourself in a few minutes.

What it cannot establish

Everything that required someone to visit, measure, search or ask.

The dividing line is not technical sophistication. It is whether the fact exists in a dataset keyed to location. A site's flood zone does. Its existing ground levels do not, because nobody has surveyed them except whoever surveyed them for you.

Levels, dimensions and survey data

Levels cause more trouble than any other missing fact, because they are invisible in a photograph and they change the answer to several policy tests at once.

Height is measured from adjoining ground level, so a sloping plot moves the compliance position for permitted development. Finished floor level drives the flood risk case. Existing and proposed levels decide whether a retaining structure is needed and whether a drainage outfall works by gravity. And the relationship between your levels and the neighbour's determines the amenity assessment.

A topographic survey of a domestic plot is not an expensive item relative to the cost of getting any of that wrong. Commission it before the drawings, not after the first refusal. The broader point about where a draft's structure is sound and its evidence is not is set out in what drafts get right about structure and wrong about evidence.

Ownership, tenure and title

Ownership facts cannot be guessed at all, and they are the ones that invalidate applications.

The ownership certificate depends on who owns every part of the red line, including any access strip, verge or shared driveway, and owner has a technical meaning that includes lessees with a long unexpired term. Agricultural tenancies trigger a separate certificate. Rights of way, drainage easements and restrictive covenants rarely stop a development outright. They change what can be built where.

Order the title register and the title plan. On a site assembled from more than one title, order all of them, and compare the plan with the red line you intend to draw. This is the commonest cause of applications being returned, as discussed in why planning applications are returned as invalid.

Planning history and existing use

A site's planning history determines what the fallback position is, which conditions still bite, and whether an earlier refusal is a material consideration.

None of it is available from a postcode. It sits on the authority's planning register under addresses that may not match the current one, and on older files that were never digitised. Search the register by address and by the adjoining addresses, then telephone and ask for the paper file references where the online record stops at 2000.

Existing lawful use is a factual question too. For a change of use application the evidence of the current and previous use, including dates and interruptions, has to come from rates records, tenancy agreements, invoices and photographs.

Closing the flags before submission

Work through them in order of lead time rather than importance.

1. Order the title register and plan, and the planning history search, on day one.
2. Commission the topographic and measured surveys, which take days rather than weeks.
3. Make the utility and undertaker enquiries, which take weeks.
4. Commission seasonal surveys early, because ecology windows can delay a scheme by months.
5. Fill each flag with the sourced fact and a note of where it came from.
6. Read the document end to end once every flag is closed, because filled facts sometimes contradict each other.

Where judgement rather than data is missing, a site visit is the only answer, which is the subject of where site judgement cannot be drafted.

What happens if a flag is left in

A submitted document carrying a visible placeholder tells the case officer that the applicant did not check their own submission, and the consequences are practical rather than cosmetic.

The authority may treat a policy test as unaddressed, which is a reason for refusal rather than a request for information. Where the missing fact is one the validation list requires, the application may not be registered at all. And an inspector reading the same document at appeal will give the unevidenced assertion no weight.

For report types where a licensed or competent professional is legally required, the flags also mark the boundary of what drafting can do, and the professional directory is the route to a reviewer who can complete and sign off that work.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. Enter your postcode on PlanScope to see which reports your site is likely to need and which facts you will have to supply.