Energy assessor competence for an energy statement

Ask who writes an energy statement and you get two answers that are both incomplete. An accredited energy assessor produces the calculations. Somebody who understands the local policy writes the document. On most schemes those are different people, and the gap between them is where energy statements fail at validation.

An accreditation to produce a compliance calculation for a dwelling is not an accreditation to write a planning document. That distinction is worth holding onto when a fee proposal lands.

What an energy statement has to demonstrate

At planning stage the statement has to show how the development meets the carbon reduction policy in the adopted local plan, which usually means a percentage improvement on the building regulations baseline, demonstrated through a staged hierarchy rather than by a single number.

In London the hierarchy is set out explicitly as be lean, be clean, be green and be seen, and the London Plan requires carbon savings at each stage with a shortfall against the target made up by a payment into the borough's carbon offset fund. Outside London the wording varies but the structure is similar: reduce demand through design first, then supply heat efficiently, then generate renewable energy, then prove it.

The document also has to address matters the calculation does not cover. Heat network connection feasibility where a network exists or is planned. Overheating risk, often cross-referenced to a separate assessment. Water efficiency where local policy sets a target. And the practicality of the measures, since an officer will notice if the photovoltaic array covers a roof the drawings show as a terrace.

Accreditation schemes and what each covers

Energy assessor accreditation is tiered, and the tiers matter because they limit which software and which buildings an assessor may work on.

Accreditation is held through government-approved schemes, which maintain registers, audit lodged assessments and require continuing professional development. Ask for the assessor's scheme and accreditation number, and ask which level it covers, because a lower-level non-domestic accreditation cannot produce the dynamic model a complex building needs.

None of these registers is a planning qualification. The policy reading, the hierarchy argument and the response to the authority's energy guidance come from experience with that authority's requirements.

Modelling the stages of the hierarchy

The staged calculation is the part that goes wrong most often, because each stage has to be modelled as a discrete case and reported as a separate emission figure.

The baseline is the regulations notional building for the relevant edition of the fuel and power approved document. The first stage models the proposal with its fabric, form, glazing ratio, air tightness and passive measures but with the baseline services. The second stage adds the heating and cooling strategy, including any communal or network connection. The third stage adds on-site renewable generation. The fourth, where local policy requires it, commits to monitoring and reporting actual performance after occupation.

Common errors in that sequence:

• claiming fabric savings in the first stage that are really the result of a heat pump, which belongs in a later stage
• modelling an air source heat pump without the space for the external units shown on the drawings
• taking photovoltaic output from a roof area that includes plant, access zones and shaded strips
• reporting only the final figure, so the authority cannot see which stage delivered the saving

Where one party produces the modelling and another submits the application, settle the scope and the responsibility in writing, as you would whenever one party writes and another submits.

Carbon factors and stating the version used

Every energy statement should say which calculation version and which carbon factor set it uses, on the first page.

The reason is arithmetical. The carbon intensity of grid electricity has fallen a long way as generation has decarbonised, and the factors embedded in successive versions of the calculation methodology reflect that. A strategy modelled on older factors can show gas heating outperforming a heat pump, while the same building on current factors shows the opposite. Officers who have seen both are alert to it.

So state the version, state the factor source and date, and note any local guidance that specifies which to use. Where the authority's own energy guidance names a methodology, follow it even if a different one is more favourable, because a statement that does not follow the published guidance invites a request for resubmission.

Where the statement meets building regulations

Two separate exercises run on the same model and they are often confused.

The planning energy statement is a design-stage document assessed against local policy. Building regulations compliance is demonstrated to building control through as-designed calculations before work starts and as-built calculations at completion, against the standards in the current fuel and power approved document.

The risk is divergence. The planning statement commits to a fabric specification and a renewable installation, the contractor substitutes an equivalent, and the as-built calculation still passes the regulations while missing the planning commitment. Nobody checks the planning condition until an occupier asks why the solar array is half the size.

Running both exercises through the same assessor, with the planning model carried forward rather than rebuilt, removes most of that risk and costs less than two separate commissions.

Securing the measures by condition

Authorities secure energy commitments by condition, and the wording of the condition decides whether the commitment survives value engineering.

Conditions that work name the measure and the performance: the fabric values by element, the installed capacity and location of the renewable technology, the heating system type, and a requirement to submit as-built calculations demonstrating the approved saving. Conditions that do not work simply require development to be carried out in accordance with the energy statement, because the statement is usually a narrative rather than a specification.

Where connection to a future heat network is relevant, the usual device is a condition requiring the building to be designed to allow connection, with pipework routes and plant space reserved, rather than a commitment to connect to something that does not yet exist.

Verification after construction

The direction of travel in policy is towards proving performance rather than predicting it. London's reporting requirement asks developments to monitor and report actual energy use after occupation, and other authorities are adopting similar conditions.

What that means practically is metering strategy at design stage, a commitment to report at defined intervals, and someone responsible for doing it after the developer has moved on. Build the obligation into the management company documents, not just the planning condition.

Independent review of the statement before submission is worth the fee where the policy target is met by a narrow margin, and the argument for a professional sign-off on an AI-assisted draft is the same argument: somebody accountable has checked the numbers.

Appointing and briefing the assessor

Appoint at the end of concept design, which is late enough for the form to be settled and early enough for glazing ratios and orientation to change.

The brief should name the local policy target and the authority's energy guidance, require the staged hierarchy with separate emission figures and a clear statement of the version and carbon factors, require the measures to be shown on the architectural drawings rather than described, and require a proposed condition wording for the measures relied on.

Reviewers in PlanScope's professional directory can review and sign off AI-drafted documents, and PlanScope's report types include the energy statement as a drafted starting point for the accredited assessor who produces the modelling. For specialist technical reports, qualified professional input may be required.

Enter your postcode on PlanScope to see which reports your scheme is likely to need.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it.