Buried in the noise of NPPF week was a data release with real consequences for where the next few years of housing schemes will come forward. On 17 August 2026, MHCLG published the 2024 and 2025 Housing Delivery Test (HDT) measurements — two years at once, after a delay, to bring the test back up to date and re-establish the annual cycle. The 2025 measurement is the current one for decision-making, and the Chief Planner’s newsletter directs authorities to use it.
What the test measures
The HDT is the government’s backward-looking check on delivery: net homes actually completed in an authority’s area over a rolling three-year period — for the 2025 measurement, 2022/23 to 2024/25 — divided by the homes required, published as a percentage. It measures completions, not permissions. An authority can be granting consents freely and still fail if the homes aren’t getting built.
It’s the counterpart to the forward-looking five-year housing land supply: one asks whether homes were delivered, the other whether enough deliverable sites exist for the next five years. Either can now expose an authority to national policy consequences.
The 2025 numbers
Of 301 authorities with a numerical result (the Isles of Scilly has none):
- 147 — nearly half — scored below 95%, triggering at least the requirement to publish an action plan;
- 35 sat between 85% and 94%;
- 19 sat between 75% and 84%, where a 20% buffer is added to the authority’s housing land supply requirement; and
- 93 — almost a third of England’s planning authorities — scored below 75%, the most serious threshold.
The remaining 154 authorities (just over half) reached 95% or above.
The 75% line now works differently
Under the pre-2026 framework, a sub-75% HDT result switched on the old paragraph 11 “tilted balance”. The August 2026 NPPF rewires this: a score below 75% now counts as evidenced unmet housing need for the purposes of policy S5(1)(j), feeding the restructured S3–S6 presumption in favour of sustainable development. For a suitable housing scheme outside a settlement in a sub-75% district, that evidence can bring the proposal within the favourable S5 policy category — and the same unmet-need evidence is relevant to the grey-belt route in Green Belt authorities.
In plain terms: in the 93 districts below the line, the policy case for housing on suitable unallocated sites just got materially stronger, and refusals in those places will be harder to defend at appeal. A low score doesn’t override design, highways, heritage, flood risk or Green Belt policy — but it changes the starting point.
The HDT Rule Book was also updated on 17 August to reflect unmet-need adjustments to local housing need and transitional arrangements for the revised standard method, and those changes were applied to both new measurements.
What this means if you build — or assess — new homes
Expect activity to cluster where the test was failed. Promoters will move on sites in sub-75% districts while the evidence is fresh; authorities under the 20% buffer will be looking to grant permissions that shore up their supply; and appeal decisions over the next year will show how inspectors handle the new S5 mechanics. The 2025 results are the current measurement until the next annual release.
For assessors and housebuilders, the timing matters. Schemes unlocked by these results will be designed and submitted straight into the Future Homes Standard transition — building regulations applications from 24 March 2027 will be under the FHS, with SAP 10.3 as the compliance methodology at launch. A site that gets its planning permission because of a weak HDT score still has to get through Part L, and under the FHS notional dwelling the fabric and bridging detail will be doing more of the work than ever.
If you’ve got schemes coming forward — especially in a sub-75% district where the planning window has just opened — get in touch about your Part L and SAP 10.3 strategy early. Bespoke thermal-bridging PSI values instead of punitive defaults remain one of the cheapest compliance margins available, and that’s exactly what ΨMonkey and our assessor team are for.
Sources: Housing Delivery Test: 2025 measurement, MHCLG, GOV.UK · Housing Delivery Test: 2024 measurement, MHCLG, GOV.UK · Housing Delivery Test measurement rule book, GOV.UK · Housing Delivery Test results 2024 and 2025 published, Planning Geek, 17 August 2026 · Planning Update Newsletter, 18 August 2026 — Letter from MHCLG to Chief Planning Officers, GOV.UK