Quick answer: The Budget on 28 October 2026 pledged no major changes to building regulations in this Parliament, except where critical for safety. That is a promise about future change. The Building Regulations etc. (Amendment) (England) Regulations 2026 (SI 2026/335) are already made, and most of the Part L and Part F changes still take effect on 24 March 2027. Keep designing and assessing to Approved Document L 2026.
What the Budget said
According to reporting on the Budget, the Chancellor told Parliament there would be “no major changes to building regulations in this Parliament, except where it’s critical for safety”. Ministers say they will carry on implementing the Grenfell Tower Inquiry recommendations and look at making rules more proportionate for developers and councils.
The Budget also reportedly confirmed that residential brownfield sites of up to 1.5 hectares will be exempt from Biodiversity Net Gain, with the implementation timetable still to follow. That builds on the smaller-site exemptions already in force (see our note on the 6 August BNG changes).
The Office for Budget Responsibility’s October outlook also reportedly named the Building Safety Levy, the Building Safety Regulator regime, BNG and nutrient mitigation among the regulatory costs that have weighed on housebuilding more than first expected.
What it does not change
- SI 2026/335 is law. It was made in March 2026. A pledge not to make new major changes does not repeal or defer regulations already made.
- The commencement date is 24 March 2027 for most provisions, including the new Part L requirements such as on-site renewable electricity generation (requirement L3).
- The transitional rules stand. For non-higher-risk work, a building notice or full plans application made before 24 March 2027, with work starting before 24 March 2028, is the main protection. Our transitional deadline explainer sets out the detail.
- Safety reform continues. Building safety is explicitly outside the stability promise, and the Building Safety Levy is a separate regime.
- England only. Building regulations are devolved.
The Budget did not define “major change” or list which rules are protected, so the practical effect will only become clear when the government next consults or amends the regulations.
Why it matters for assessors and developers
Two things follow. First, the pledge makes it less likely that the Part L 2026 package is reopened or watered down mid-Parliament, which matters given the Conservative conference proposal to scrap the Standard (an opposition position, not law). Second, there is no reason to expect a reprieve: schemes that will not secure transitional protection should be designed to the 2026 Approved Documents now.
Practically, that means checking each live site: when will the application be made, when will work start, and does the house type already meet the L3 solar PV requirement and the new SAP 10.3 targets?
Need help with Part L 2026?
If you have house types that straddle the March 2027 deadline, we can assess them under both regimes so you can decide which route makes sense.
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Budget details are drawn from press and legal-sector reporting of the 28 October 2026 Budget; check the Budget document for the exact wording.