Unregulated energy and why it is left out

Unregulated energy is everything the Building Regulations do not control: cooking, appliances, small power at the socket, lifts, external lighting, server rooms, commercial catering. Part L compliance calculations leave it out entirely, which is why a scheme can show a large percentage reduction in regulated emissions and still use more energy in practice than the figure suggests.

For a planning consultant the practical problem is that the two numbers get mixed up. Policy asks for one, the SAP or SBEM output gives the other, and a carbon offset calculation applied to the wrong base can be wrong by a wide margin in either direction. Getting the boundary right is the whole job.

What regulated and unregulated actually cover

Regulated energy is the energy used by fixed building services, which for a dwelling means space heating, hot water, cooling, ventilation, fixed lighting and the pumps and fans that serve them. For a non-domestic building the same list applies with fixed lighting assessed in more detail.

Unregulated energy is everything else the occupier plugs in or brings with them. Appliances and cooking in homes. Small power, IT, catering, lifts and escalators, specialist process loads and external lighting in commercial buildings.

The split is not a judgement about importance. In a well-insulated new flat with a heat pump, unregulated energy can be the larger share of total electricity use, and it is entirely absent from the compliance figure the Energy Statement is built on.

Why the regulations exclude appliances

The Building Regulations control what the builder provides and hands over. A developer specifies the boiler or heat pump, the ventilation system and the light fittings, so the Regulations can set a performance standard for them and test compliance at completion.

Nobody controls what kettle the occupier buys. Appliance efficiency is regulated through product standards and energy labelling rather than through building control, so bringing it into a building compliance calculation would set a standard the builder cannot deliver and the building control body cannot check.

That is a coherent boundary for Building Regulations. It is a poor boundary for planning policy that is trying to reduce actual emissions, and the tension between those two purposes explains most of the confusion in submitted energy statements.

Where policy asks for unregulated emissions anyway

Several authorities ask for total emissions alongside the regulated figure, and the London Plan approach is the one most widely copied. The energy hierarchy, be lean, be clean, be green and be seen, is applied to regulated emissions for the purposes of the percentage reduction target and the offset calculation, while unregulated emissions are reported separately for information.

The "be seen" stage then asks for actual in-use energy data after completion, and in-use data does not respect the regulated boundary at all. A meter reads what the building uses. So a scheme that reported only regulated emissions at application stage will be reporting a much larger number at monitoring stage, and the gap gets read as underperformance when it is partly a change of accounting basis.

Whole life carbon assessment is the other place the boundary bites. Operational energy in a whole life assessment covers total energy use, including unregulated, so a Whole Life Carbon Assessment prepared to the RICS methodology will not reconcile with the energy statement unless the difference is explained. Reviewers do notice.

Estimating unregulated demand credibly

There is no compliance tool for this, which means the estimate has to be built from benchmarks and stated as an estimate.

For non-domestic buildings the usual approach is a CIBSE TM54 style operational energy estimate, using benchmark end-use intensities adjusted for the specific brief. For dwellings, appliance and cooking energy can be taken from published benchmark data and scaled by occupancy and floor area.

Three things make an estimate defensible:

1. Name the benchmark source and its year, and say what it covers.
2. State the occupancy and operating hours assumed, because a 24-hour operation changes the answer more than any equipment choice.
3. Separate the loads that are not yet known, such as a tenant fit-out or a future server room, and give a range rather than a point figure.

Avoid the temptation to present an unregulated figure to three significant figures. An estimate that looks precise invites a challenge it cannot survive, and the honest position is a banded figure with the assumptions on the page.

Effect on offset payment calculations

Carbon offset payments are normally calculated on residual regulated emissions after on-site measures, multiplied by a period of years and a price per tonne set by the authority. Both the period and the price vary, and the price is reviewed, so take the current figure from the authority's own published schedule rather than from a previous scheme.

The mistake worth watching for is a payment calculated on total emissions. It produces a number that can be several times the correct one, and once it has been offered in a submitted energy statement it is difficult to reduce without looking as though the scheme is retreating. Check the base of the calculation before the document goes out.

The reverse error also happens. A scheme claims a percentage reduction against a total emissions baseline while calculating the offset on the regulated residual, which is internally inconsistent and gets picked up by the borough's energy reviewer. Use one baseline throughout and label it.

Renewables sized against which demand

Photovoltaic output offsets whichever demand it is credited against, and that choice changes both the compliance result and the real-world outcome.

For Part L and for the regulated percentage reduction, generation is credited against regulated demand. For actual operational performance, the array is competing with total site demand, and on a scheme with a heat pump and high small-power loads a roof-filling array may cover a modest share of the total.

Size the array for the roof and the structure, then report its contribution twice: once against regulated demand for the policy test, once against estimated total demand for the operational picture. That second figure is what makes an energy strategy credible at committee, and it is also what protects you when in-use data arrives. Where a cooling strategy is also in play, the demand side has to be settled first, which is the argument set out in proving the cooling hierarchy.

Reporting both figures clearly

Put a single table near the front of the energy statement showing regulated emissions at each stage of the hierarchy, unregulated emissions as an estimate with its basis, and the total. Label the offset calculation with the base it uses and the authority's current rate.

Then say in plain words which figure the policy target applies to. Officers reviewing a dozen energy statements a month are looking for that sentence, and its absence is the most common reason a statement comes back with questions.

Where the strategy will be secured by condition, the wording needs to follow the same boundary. A condition requiring "the development to achieve a 35 per cent reduction" without saying regulated, against which baseline and at which stage, is a condition that will be argued about at discharge. Drafting that holds up is covered in securing an energy strategy through planning conditions.

And be honest about the residual. A scheme that reports a 60 per cent regulated reduction and a total energy figure barely below the notional building is telling the truth about where the remaining emissions sit. That is a stronger position than a clean-looking number that cannot be reconciled with the first year of meter readings.

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This is general guidance rather than legal advice. Check the position with your local planning authority or a qualified energy assessor 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.