Can a local plan proceed where whole evidence topics are absent?

Local plans are frequently advanced on the basis that the overall evidence base is “sufficient for the stage reached”, even where entire topic areas contain little or no substantive assessment.

This raises a narrow but important procedural question.

Can a local plan lawfully proceed where whole evidence topics are absent at the point a formal plan-making decision is taken?

This page explains why the absence of complete topic-level evidence creates governance risk, how authorities attempt to characterise such absence, and why the issue is material in judicial review.

What is meant by “whole evidence topic absence”

Whole-topic absence arises where an evidence category relevant to the plan contains no completed assessment capable of informing decision-making.

Examples include:

no walking, cycling, or road safety assessment,
no transport modelling or junction capacity analysis for affected locations,
no utilities or drainage capacity assessment for proposed growth,
no accessibility analysis to essential services.

This is not a question of evidential weight or quality. It is a question of existence.

Where no assessment has been undertaken, there is nothing for the decision-maker to evaluate.

Absence versus evidential insufficiency

Authorities often seek to characterise missing topic evidence as merely “limited”, “high-level”, or “proportionate for the stage”.

There is a material difference between:

insufficient evidence, where some assessment exists but may be contested, and
absent evidence, where no substantive assessment exists at all.

In the latter case, there is no analytical basis on which a planning judgment can be formed.

A decision taken in the absence of evidence is not a decision taken on inadequate evidence — it is a decision taken without evidence.

How authorities commonly justify topic absence

Where whole evidence topics are absent, authorities commonly rely on explanations such as:

“The matter will be addressed at a later plan-making stage.”
“Further work is ongoing.”
“The issue can be explored through subsequent consultation.”
“The evidence base is iterative.”

These explanations acknowledge that assessment has not yet occurred.

They do not convert absence into sufficiency.

Where a topic has not been assessed at all, there is no evidential basis on which to lawfully conclude that impacts are acceptable.

Why whole-topic absence matters at decision stage

Each formal step in local plan preparation involves a decision to proceed.

At that point, the authority must be able to demonstrate that it has sufficient evidence to justify the judgment it is making at that stage.

Where entire topic areas are unassessed, the authority cannot lawfully conclude that:

the proposed strategy is deliverable,
impacts are acceptable, or
mitigation is feasible.

Proceeding in those circumstances is not a matter of evidential balance. It is a failure to cross the decision-stage evidential threshold.

Why later evidence does not cure topic absence

Authorities sometimes argue that the later production of topic evidence demonstrates that earlier decisions were justified.

This is a form of retrospective reasoning.

Evidence produced later does not demonstrate that it existed, or was available, when the earlier decision was taken.

Where a plan is advanced in the absence of topic-level assessment, the later completion of that work does not retrospectively validate the earlier step.

The legality of each decision is fixed at the moment it is made.

Why whole-topic absence is material in judicial review

In judicial review, courts examine whether the authority had a rational and lawful evidential basis for the decision it took.

Where whole topics are unassessed, the authority may be unable to show that it lawfully addressed matters that were obviously relevant to its judgment.

This is particularly acute where:

the missing topic relates to infrastructure capacity,
the impacts are location-specific, or
the authority itself acknowledged the need for further work.

In such circumstances, proceeding without evidence exposes the decision to challenge regardless of later plan iterations.

Analytical focus in governance review

Governance analysis focuses on whether the authority crossed a decision threshold without having assessed matters that were necessary to justify that step.

It does not assume that unassessed topics can be lawfully deferred, nor that later work can supply justification retrospectively.

Where whole evidence topics are absent, the analysis records this as decision-stage evidential failure.

The boundary remains unchanged: legality is determined at the point the decision is taken, not as later explained.

PGAT

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