All-electric new homes and the gas connection decision
Leaving gas out of a new housing scheme is a design decision that has to be evidenced at application stage. Here is what councils expect to see.
Leaving gas out of a new housing scheme is now a planning decision as much as a services decision, because the evidence you file at application stage has to show that an all-electric scheme works. That means heat pump locations on the drawings, an electrical load position agreed in principle with the distribution network operator, fabric performance that suits low flow temperatures, and an overheating assessment that survives the extra insulation. Councils increasingly expect the question to have been answered rather than deferred.
The direction of travel is set by the Future Homes Standard, which government has consulted on with the intention of ending reliance on fossil fuel heating in new homes. Check its commencement position on gov.uk before you rely on a date, because the timetable has moved more than once.
Why the gas question moved into design
Three forces pushed it there. Building Regulations tightened with the 2021 uplift to Part L, which made high-carbon heating harder to justify in the calculation. Planning policy in many authorities now asks for carbon reductions beyond the regulations, with London operating its own energy hierarchy and carbon offset mechanism through the London Plan. And gas network connections for new estates are increasingly seen as assets with a short life.
The result is that a scheme designed around a gas boiler in each home has to explain itself, while a scheme designed around heat pumps has to prove it works. Both need evidence. Only one of them is swimming with the current.
Note that the planning decision and the regulations decision are separate. A council cannot refuse permission because a home fails Part L, and a building control body cannot approve a home that meets Part L but breaches a planning condition about the energy strategy. Design to both.
Capacity and connection, before anything is fixed
The single most common cause of a late redesign is electrical capacity. A heat pump, a hot water cylinder with an immersion backup, an induction hob and an electric vehicle charge point together draw far more than the gas-heated house they replace, even after diversity is applied.
Approach the distribution network operator early with a load estimate and a site plan. What you are looking for is whether the existing network can take the diversified load, whether a new substation is needed, and what the reinforcement cost and lead time look like. On a scheme of twenty or more homes, a substation usually appears somewhere, and it needs a location on the layout that is not the visitor parking bay you were relying on.
Three practical points follow.
- Substation kiosks need vehicular access for maintenance and a clear zone around them, so put them on the layout at the same time as the bin stores.
- Reinforcement quotations expire, and the lead times for network works are often longer than the planning determination period.
- Where the site is in a heat network zone, a connection requirement may apply instead, which changes the plant strategy entirely. That interaction is covered in heat network zoning and the connection requirement.
Fabric that makes a heat pump work
Heat pumps run efficiently at low flow temperatures, which means the emitters have to be sized for something closer to 45 degrees than 70. Underfloor heating on the ground floor with oversized radiators above is the common compromise. Retrofitting that logic after the layouts are fixed causes trouble, because larger radiators need wall space that a tight two-bed plan may not have.
Airtightness and insulation carry the rest of the load. A fabric-first design reduces the peak heat demand, which reduces the heat pump size, which reduces the electrical load and the noise. Every one of those is a planning issue as well as an energy one, because unit size and position affect the elevations and the neighbour relationship.
Ventilation follows. Tighter homes need a designed ventilation strategy, and mechanical ventilation with heat recovery brings ducting, terminals on the elevations and a plant location in each dwelling. Show the terminals on the drawings rather than leaving them to a contractor's discretion.
Overheating, which the extra insulation makes worse
An all-electric, highly insulated home with large south-facing glazing overheats unless it is designed not to. Approved Document O brought that into the regulations, and planning officers now ask about it because the mitigation shows on the elevations as brise soleil, reduced glazing, external shutters or deeper reveals.
Run the assessment early and let it inform the design. Where a dynamic thermal model to CIBSE TM59 is used, its outputs should match the windows on the planning drawings, and an Overheating Risk Assessment submitted with the application avoids a second round when the elevations change to add shading.
Noise is the other consequence of external plant. Air source units sit outside, and the assessment methods used for permitted development installations give a reasonable starting point for the acoustic case. Position them away from bedroom windows, including the neighbour's, and show the location on the site layout.
Cooking, hot water and what residents expect
Induction hobs are the usual answer and they are a genuine improvement over electric resistance cooking, but they need a circuit and a pan set, and the sales narrative needs to cover it. Hot water comes from a cylinder, which needs a cupboard, and that cupboard is space a combi boiler did not require. On small flats this is the detail that pushes a plan over the nationally described space standard.
None of this is a planning objection in itself. It becomes one when the submitted layouts have no cylinder cupboard and the officer notices that the energy strategy and the floor plans describe different buildings.
The evidence to put in the energy statement
An Energy Statement for an all-electric scheme should do six things, and do them in a way a non-specialist officer can follow.
- State the heating and hot water strategy for each house type, with the equipment and its location
- Set out the fabric specification and the resulting space heating demand
- Show the carbon position against the relevant Part L target, with the calculation method named
- Give the diversified electrical load and the network position, including any substation
- Deal with overheating and ventilation, with the assessment method stated
- Explain any offset payment or local policy requirement and how it is satisfied
Where the council's policy asks for a percentage improvement over the regulations, show the baseline and the proposal side by side rather than asserting the result. Carbon figures in the statement should be the same figures used in the Whole Life Carbon Assessment where one is required, because inconsistency between the two is the fastest way to lose an officer's confidence.
Conditions that lock the strategy in
Expect a condition requiring the development to be carried out in accordance with the approved energy statement, and a further condition requiring evidence before occupation that it has been. That second one is where schemes come unstuck, because value engineering during construction quietly substitutes a different heat pump or drops the mechanical ventilation.
Write conditions you can actually discharge. A condition that requires "an as-built assessment demonstrating the carbon reduction in the approved energy statement" is dischargeable. A condition requiring "zero carbon in operation" is not, and it will sit on the title for years. The drafting principles are set out in drafting carbon conditions that can actually be discharged.
And if the scheme cannot go all-electric, say why with numbers. A network constraint evidenced by a distribution network operator quotation is an argument. A preference for boilers is not.
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.
Frequently asked questions
Can a council refuse permission because a scheme uses gas heating?
Not on regulations grounds, because Building Regulations compliance is a separate process. A council can refuse on policy grounds where its adopted local plan sets carbon or energy requirements that a gas-heated scheme fails to meet. Check the adopted plan and any supplementary guidance, and check whether a written ministerial statement limits what the authority may require.
When should I talk to the distribution network operator?
Before the layout is fixed. You need to know whether the existing network can carry the diversified load of heat pumps, hot water and vehicle charging, whether a substation is needed, and what reinforcement will cost and take. Substations occupy space on the layout, so finding out after the drawings are issued means redesigning the scheme.
Do heat pumps need planning permission on a new estate?
On a new scheme the units form part of the application, so they are approved with everything else. Show each unit on the site layout and the elevations, with the model and its acoustic data in the energy statement. Position matters, because units close to bedroom windows, including neighbouring ones, attract objections and conditions.
Why does an all-electric scheme need an overheating assessment?
Because the fabric that makes a heat pump efficient also traps heat. Approved Document O brought overheating into the Building Regulations, and the mitigation appears on the elevations as shading, smaller glazed areas or deeper reveals. Running the assessment after the planning drawings are issued usually means changing them, so run it first.
What conditions should I expect on the energy strategy?
A condition requiring the development to follow the approved energy statement, and a pre-occupation condition requiring evidence that it has. Push for wording that names a specific deliverable, such as an as-built assessment, rather than an outcome like zero carbon in operation, which cannot be evidenced and leaves the condition undischarged.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.