What counts as evidenced unmet need in the 2026 NPPF?

The two named measures

The framework gives two examples: the lack of a five year supply of deliverable housing sites, including any relevant buffer, and a Housing Delivery Test result below the threshold. Either is enough on its own, and they are the most commonly argued because the evidence is a matter of public record.

Delivery test results are published annually by the government, one figure per authority. Five year supply is not centrally published: it comes from each council's own position statement or annual monitoring report, and it is actively contested, so an appeal decision often carries more weight than the council's own claim.

The needs beyond them

The examples are not the limits: the phrase used is 'including, but not limited to'. An unmet need for affordable housing, for homes for older people, for rural housing, or for self-build plots can all qualify, provided the need is genuinely evidenced.

Self-build is the clearest of these, because the evidence is statutory. Councils must keep a register of people seeking plots and grant enough suitable permissions to meet the demand on it. A council that has not is in breach of a statutory duty, and its own register proves the shortfall.

What evidenced means in practice

The need has to be demonstrated, not merely asserted. The strongest sources are the council's own documents: the housing needs assessment, the self-build and custom build register, and the annual monitoring report. An argument built from the council's own evidence is hard for the council to dispute.

Where the council has never assessed a named group's needs at all, that gap is itself an argument, though a weaker one than positive evidence of a shortage.

One caveat in the Green Belt

The grey belt route uses the same phrase, but a footnote narrows it there to the two named measures. Inspectors at appeal have counted unmet self-build demand under that test as well, so far always alongside a five year supply shortfall; no positive decision has yet rested on self-build alone. The grey belt page covers that argument in full.