If you’ve ever run a SAP calculation twice — once for Building Control and once for a local plan policy demanding “a 35% improvement on Part L” — you’ll have followed the NPPF consultation with some interest.
The December 2025 draft NPPF proposed, at policy PM13, that local plans should not set quantitative standards covering matters already addressed by Building Regulations. Read literally, that would have ended local energy, carbon and overheating targets: Building Regulations would have become both the floor and the ceiling. The consultation closed on 10 March 2026 and drew a lot of noise from councils and the low-energy sector.
The final Framework was published on 17 August 2026, replacing the December 2024 version. On this point, the government changed its mind.
What PM13 actually says now
Policy PM13 still tells plan-makers that quantitative standards should “not cover matters that are already addressed by Building Regulations” — but it now carves out three exceptions. The energy one is worth reading properly:
“Energy efficiency, for which any standards that go beyond the current or proposed Building Regulations should have a clear and robustly costed rationale which shows that there will not be an adverse impact on the viability and deliverability of development. Any such standards should be expressed as a percentage uplift of a dwelling’s Target Emissions Rate (TER) calculated using a specified version of the Standard Assessment Procedure (SAP) or other approved calculation methodology.”
The other two exceptions are accessibility (M4(2)/M4(3), set in accordance with policy HO5) and water efficiency (the tighter optional requirement where justified, or exceptionally something more stringent in areas of serious water stress).
So local ambition survives. But it has to arrive in a specific currency.
Why the “percentage uplift on TER” wording matters
This is the part that lands on assessors’ desks rather than planners’.
At the moment, local energy policies are written in whatever unit the authority fancied at the time: kgCO₂/m²/yr targets, space-heating demand limits in kWh/m²/yr, “net zero carbon” definitions, energy use intensity caps, Passivhaus-equivalent wording. Some of those can’t be evidenced from a SAP output at all, which is how you end up with a planning condition that no compliance calculation can cleanly discharge.
PM13 pushes all of that back into a single, familiar metric — DER against TER, as a percentage — and requires the plan to name which version of SAP the percentage is measured against.
That last clause is not a footnote. A “31% uplift” means something quite different under SAP 10.2 than it does against the SAP 10.3 notional building used for the Future Homes Standard, where the target has already moved a long way. A policy that doesn’t pin its version down is a policy that will be argued about at appeal.
There’s also a viability test attached: the rationale must be “clear and robustly costed” and show no adverse impact on the viability and deliverability of development. Expect that to be where most of the examination argument happens.
The Future Homes Standard collision
Worth holding both dates in your head.
The Future Homes and Buildings Standards come into force on 24 March 2027 for non-higher-risk work, with transitional protection for plots where a valid application was made before that date and work is commenced before 24 March 2028. From then, the notional dwelling gets very demanding indeed — and requirement L3 mandates on-site renewable electricity generation.
A local policy demanding a percentage uplift on a post-FHS TER is a materially different ask from the same percentage against the 2021 baseline. Many existing local plan policies were written against Part L 2013 or 2021 targets and will need revisiting; PM13 gives examiners a clear basis for asking authorities to show their working.
What this means in practice
If you’re a housebuilder or developer: check the energy policies in the local plans covering your live sites, and specifically whether they name a SAP version. Where they don’t, the new PM13 wording is a reasonable basis for asking the authority what baseline it thinks it is measuring against — before you price the specification.
If you’re an assessor: expect more requests for a dual output — the Part L compliance case, plus a stated percentage improvement of DER over TER for the planning condition. Getting both from a single, consistent model saves an argument later.
If you’re in Building Control: nothing changes for you directly. PM13 is a plan-making policy. But it should, over time, reduce the number of planning conditions that ask for something Building Control has no way of verifying.
What we’d suggest doing now
Don’t rewrite specifications on the strength of a planning policy that may itself be revised. Do find out where you actually sit.
For a percentage-uplift policy, the number that decides everything is the DER/TER margin — and on most schemes the cheapest place to find margin is the thermal bridging. Default PSI values are deliberately pessimistic; calculated junction values routinely recover several percent of the emissions rate without changing a single product on the specification.
ΨMonkey calculates bespoke PSI values for your junctions to BR 497 and BRE IP 1/06 conventions, so your SAP model reflects the details you’re actually building rather than the worst case the software assumes.
If you’ve got a site where a local plan energy policy and the Part L case are pulling in different directions — or a condition that names no SAP version at all — get in touch and we’ll tell you how we’d approach it.
Sources: National Planning Policy Framework, August 2026 (PDF), GOV.UK · Full steam ahead to fast-track more homes near stations — MHCLG press release, 17 August 2026 · The Building Regulations etc. (Amendment) (England) Regulations 2026 (SI 2026/335), legislation.gov.uk