What an energy statement for a single new dwelling needs

An energy statement single dwelling submission is usually two to four pages, not the 40-page document a major scheme produces. The first question is whether you need one at all, and the answer sits in your council's local validation list rather than in national policy. Check it before you commission anything. Plenty of authorities ask for nothing beyond the application forms for a single house, and plenty ask for a short energy and sustainability note, and a few ask for a full statement with design-stage calculations attached.

Working out whether it is required

National validation requirements are set nationally and local ones are set by each authority, published as a validation checklist on its website. That checklist is the document that decides this.

Look for three entries: energy statement, sustainability statement or checklist, and any local policy requiring a percentage improvement on Building Regulations. Note which ones are marked as applying to all residential development and which are limited to majors. A single dwelling is a minor application, so requirements framed around major development usually do not bite.

Where the checklist is ambiguous, email the validation team with the site address and the proposal, and keep the reply. A one-line confirmation that no energy statement is required has saved more applications from invalidation than any amount of guesswork.

There is a policy complication worth knowing about. Ministerial statements have at various points limited what local plans can require of dwellings beyond the Building Regulations, and the position has shifted more than once. Some adopted plans still carry percentage improvement policies. Read the adopted plan, note the date, and ask the officer how the policy is currently applied.

What a proportionate document contains

For a single house, the content that earns its place is short.

• The site, the proposal and the floor area.
• The policy the document responds to, named and dated.
• Fabric performance: U-values for walls, roof, floor, windows and doors, plus the airtightness target and the approach to thermal bridging.
• The ventilation strategy, matched to the airtightness figure.
• Heating and hot water: the system, its efficiency, and why it suits the plot.
• Renewables: what is proposed, sized to the roof and the load.
• Design-stage calculation outputs showing the dwelling meets or betters the Part L targets.
• Overheating: the route taken under Part O and the outcome.

That is it. Resist the temptation to reproduce national policy at length. An officer reading a single-dwelling application wants to see numbers and a system, and a page of NPPF paraphrase suggests you are padding.

The Energy Statement page sets out the full structure where a larger scheme needs it, and the same skeleton scales down cleanly.

Using design-stage calculations properly

Part L 2021 for new dwellings works through three targets: a carbon emission target, a primary energy target and a fabric energy efficiency target. The design-stage calculation produces figures for all three, and the dwelling must satisfy each.

Attach the summary output, not the full workings. Show the target and the achieved figure side by side so the officer can see the margin.

Two cautions. The design-stage calculation is a design tool, and the as-built version has to reflect what was actually built, so quoting a heroic airtightness figure at planning creates a problem for you at completion rather than for the council. And do not present the calculation as though it were a planning policy compliance statement. It demonstrates Building Regulations compliance, which is related but separate, and conflating the two is the single most common weakness in small-scheme energy documents. The assumptions officers challenge are worth reading before you settle the inputs.

Heating and hot water on a rural plot

Most self-build plots outside towns have no gas connection, which simplifies the decision rather than complicating it.

An air source heat pump is the default. Size it to the calculated heat loss rather than to a rule of thumb, because an oversized unit cycles, runs inefficiently and is noisier than it needs to be. Ground source works where the land and budget allow, with either boreholes or a horizontal collector, and the collector area needed is substantial.

Note the planning position. A heat pump on a house can fall within permitted development under Part 14 of the GPDO subject to conditions and limits, including noise requirements. Those limits are specific, and a unit sited near a boundary or on a listed building may need permission. Where the plot sits in a conservation area or the pump is part of the application anyway, describe its position and the manufacturer's sound power level in the submission.

Hot water needs a cylinder, and a heat pump needs a larger one than a boiler did. Find the space at plan stage. Retrofitting a 250-litre cylinder into a completed house is a carpentry problem nobody enjoys.

Sizing renewables on a single plot

Photovoltaic panels are the usual answer, and the sizing question is roof-led. South-facing is best, east and west lose a modest amount, and north-facing is not worth the money.

Size the array to the dwelling's own consumption plus a reasonable margin, then consider a battery if the pattern of use justifies it. Oversizing an array to hit a policy percentage produces export at low value and an ugly roof, and officers in sensitive settings will push back on the visual impact before they applaud the carbon saving.

Solar on a dwelling is generally permitted development under Part 14, with limits on projection and on siting in conservation areas and on listed buildings. Where the panels are part of the application, show them on the elevations rather than mentioning them in the text. An array that appears for the first time at building control stage is a variation, and a conservation officer who sees it then will not be pleased.

Overheating and the conditions to expect

Part O applies to new dwellings, and it is assessed either through the simplified method with its limits on glazing area and free area for ventilation, or through dynamic thermal modelling following the CIBSE TM59 approach.

The simplified route is the sensible one for most single houses, and it constrains the design: large south and west glazing with limited openable area will fail it. Test this at sketch stage, because the fix is usually shading or a smaller window, and both cost far less on paper than on site. Where modelling is needed, an Overheating Risk Assessment is the document that reports it.

Expect conditions requiring materials, and sometimes a condition requiring the approved energy measures to be installed before first occupation. Read that wording carefully, because a condition tying you to a named heat pump model is a nuisance if the model is discontinued during the build. Ask for the wording to refer to performance rather than product.

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

Draft your energy and sustainability documents on PlanScope, then have the calculations checked by your energy assessor.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.