Building regulations transitional dates and starting on site

Building regulations transitional dates work off the building control paperwork and the date work starts on each individual building. They have nothing to do with when planning permission was granted or when it expires. A self-builder who assumes that an old planning consent protects an old energy standard has confused two separate regimes, and the discovery usually comes when building control asks for a SAP calculation against the current Approved Document.

How transitional provisions work

When the Building Regulations are amended, the amending instrument carries transitional provisions setting out which projects continue under the previous standards. The pattern is consistent across recent changes and has two limbs.

The first limb is the notice. A building notice, an initial notice or full plans must have been given to or deposited with the building control body before the date the change takes effect. The second limb is the start. Work on each building must actually begin before a later date, typically twelve months after the change.

Both limbs have to be satisfied. A full plans application deposited in good time is worthless if nothing is built within the following year, and a genuine start is worthless if no notice was given in time.

That structure is why the Part L, F, O and S changes that took effect in June 2022 continued to produce buildings assessed under the earlier standards well into the following year, and why the same pattern should be expected whenever the Future Homes Standard takes effect. Check the transitional wording in the relevant amending instrument itself rather than a summary, because the dates differ between amendments and the drafting varies.

What counts as starting work

This is where self-builders come unstuck. Starting work means a real start on the building, not a token gesture, and building control bodies ask for evidence.

Digging a trial hole, pegging out the plot, clearing vegetation or bringing a welfare unit onto site are not a start. Excavating the foundation trenches for the building, laying the foundations, or beginning the substructure in a continuous programme generally is.

The safest position is a start that is visible, recorded and continuous. Photographs with dates, delivery notes for concrete and blocks, the groundworker's invoices, and a building control inspection of the excavation before pouring together make an unarguable record. An inspection is worth arranging specifically for this purpose even where one would not otherwise be called.

Individual buildings within a larger scheme

On a scheme of several plots, the transitional provision usually applies building by building rather than to the site as a whole. Plot one started in time continues under the old standards. Plot six started three months after the cut-off does not.

That has a design consequence. A developer relying on transitional provisions across a phased site needs either a programme that starts every building in time or two versions of the energy strategy, one per standard. Producing one design and hoping is how a scheme ends up with two plots that cannot be signed off.

Record the start date for each plot separately, with its own photographic record and its own inspection. A single site-wide start date is the record that fails when it is examined.

Records that support a transitional claim

Keep these together in one file from day one.

1. The initial notice or full plans deposit, with the date of receipt acknowledged by the building control body.
2. The approved drawings and specification as deposited, since the transitional protection attaches to that work.
3. Dated photographs of the excavation and foundations for each building.
4. Invoices and delivery notes showing continuous activity across the start period.
5. Building control inspection records with dates.

Two years later, when a purchaser's surveyor asks why a dwelling was built to a superseded standard, that file is the answer. Without it the practical outcome is a retrospective upgrade or a discount at sale.

Effect on the energy strategy

The difference between successive editions of Approved Document L is not cosmetic. Fabric standards, the calculation methodology and the notional dwelling used for comparison all change, and the specification that passed under the earlier edition can fail under the later one on the same drawings.

Where a project sits close to a cut-off, get the calculations run against both editions before the notice is given. The cost is small against the risk of redesigning a heating strategy after the slab is down. An Energy Statement prepared for the planning application is not the same document as the compliance calculation for building control, and the two need to be consistent so that the planning condition and the building regulations approval do not pull in opposite directions.

Overheating is the change that catches retrofitted designs most often. Where Part O applies, the assessment can force changes to glazing areas, shading and ventilation openings that alter the elevations, which then needs checking against the planning permission. An Overheating Risk Assessment done early avoids amending drawings that have already been approved.

Why the planning permission date does not help

Planning permission and building regulations approval are separate consents with separate rules. The date of the planning permission, the three-year implementation period and the material start for planning purposes have no bearing on which edition of the Building Regulations applies.

The material start tests are different too. A start sufficient to implement a planning permission, which can be a modest operation such as digging a foundation trench in accordance with the approved plans, is not necessarily a start sufficient for a building regulations transitional claim, where the question is whether work on that building really began.

Treat them as two separate diaries. It is entirely possible to have implemented a planning permission and still be required to build to the current Approved Document.

Risk of relying on an old approval

Transitional protection has a shelf life and it is not renewable. A project that stalls loses it, and there is no mechanism for extension.

It is also worth asking whether you want it. A dwelling built to a superseded standard has higher running costs, a worse EPC rating and a smaller pool of buyers in a market where energy performance is priced in. The commercial case for racing a cut-off is weaker than it looks for anyone intending to live in the house.

Illustrative example: a single self-build plot with full plans deposited six weeks before a cut-off and foundations poured four months later, photographed and inspected. The house is built to the earlier standard, signed off without difficulty, and the owner spends the saving on a larger solar array. A neighbouring plot with the same paperwork but no start for fourteen months is redesigned at the owner's cost.

Planning the submission and the start

Work backwards from the cut-off date. Allow time for the building control body to acknowledge the notice, for the groundworker to be booked, and for weather. Then add a month.

And check the planning conditions before breaking ground. Pre-commencement conditions have to be discharged first, and a start made to secure a building regulations transitional position while a pre-commencement condition is outstanding can be an unlawful start for planning purposes.

This is general guidance, not legal advice. Check the position with your local planning authority, your building control body or a qualified professional before relying on it.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. Browse the energy and sustainability report types to see what a new dwelling application usually needs.