New Build Heat Pump Requirements in 2026: What Developers Must Know

The Regulatory Landscape Has Changed — Permanently

New build heat pump requirements in 2026 are not a future concern — they are the present reality. The combination of the Part L 2021 uplift, the Future Homes Standard, and the practical disappearance of new gas connections has made low-carbon heating effectively mandatory for residential developers. Developers who build heat pumps and solar PV into their feasibility assessments from day one will deliver compliant, saleable homes efficiently. Those who treat renewable energy as an afterthought will face costly redesigns, programme delays, and increasingly difficult conversations with building control.

Related reading: Heat pumps for property developers: compliance made simple | Future Homes Standard: how it changes everything for builders

Part L 2021: The Current Baseline

The current edition of Approved Document Part L (Conservation of Fuel and Power) came into force in June 2022. It applies to all new dwellings where building control applications were submitted after that date, and by 2026, virtually every new project falls under these rules.

What Part L 2021 requires

Part L 2021 introduced a 31% reduction in carbon emissions compared to the previous 2013 standard. In practical terms, this means:

• Improved fabric standards: Lower U-values for walls, floors, roofs, and windows. The Target Fabric Energy Efficiency (TFEE) rate must be met alongside the Target Emission Rate (TER)
• Low-carbon heating strongly favoured: While Part L 2021 does not explicitly ban gas boilers, hitting the 31% carbon reduction target with a gas boiler is extremely difficult and usually requires expensive compensatory measures
• Solar PV effectively standard: Most SAP calculations for Part L 2021 compliance include solar PV as a baseline assumption
• Improved airtightness targets: Tighter as-built air permeability expectations

Why gas boilers are already impractical

To pass the SAP assessment with a gas boiler under Part L 2021, you typically need a larger solar PV array, higher specification insulation, triple glazing in many cases, and additional measures such as waste water heat recovery. The additional cost of these compensatory measures generally exceeds the cost of simply specifying a heat pump. Most developers have already made the switch.

Gas network connections

Gas network operators are increasingly reluctant to extend the gas network to new developments. From 2025, no new homes connected to the gas grid are permitted under the Future Homes Standard, making any current gas connection investment a stranded asset.

The Future Homes Standard: What Is Coming

The Future Homes Standard (FHS) was confirmed by the government in 2025 and represents the next major step-change in building regulations for new dwellings.

Key requirements of the Future Homes Standard

• 75–80% reduction in carbon emissions compared to the Part L 2013 baseline — more than double the current 31% reduction under Part L 2021
• Mandatory low-carbon heating: Heat pumps (or equivalent low-carbon systems) are explicitly required. Gas boilers are prohibited in new dwellings
• Enhanced fabric standards: Further improvements to U-values, thermal bridging, and airtightness
• Ventilation requirements: Mechanical ventilation with heat recovery (MVHR) is expected to become standard in most dwelling types
• Solar PV as standard: The FHS specification assumes solar PV on every dwelling as a baseline
• No fossil fuel heating: The standard explicitly prohibits connection to the gas grid for space heating and hot water in new homes

Timeline and transitional arrangements

The Future Homes Standard applies to all new dwellings where building control applications are submitted from the implementation date. Projects currently in the planning or building control system before the cut-off may still be assessed under Part L 2021. Any project currently in the feasibility or early design stage should be designed to FHS standards from the outset.

Related reading: Future Homes Standard: how it changes everything for builders

SAP Calculations: The Numbers That Matter

The Standard Assessment Procedure (SAP) is the methodology used to demonstrate compliance with Part L. For developers, the SAP calculation is the single most important document in determining whether a dwelling passes or fails building regulations for energy performance.

How heat pumps affect SAP ratings

Heat pumps dramatically improve SAP ratings compared to gas boilers because of their high efficiency. A typical air source heat pump has a Seasonal Coefficient of Performance (SCOP) of 3.0–4.0, meaning it produces 3–4 kWh of heat for every 1 kWh of electricity consumed.

A well-designed new build with an air source heat pump (SCOP 3.5+), a 3–4 kWp solar PV array, good fabric performance, and reasonable airtightness will typically achieve an EPC A rating (SAP score 92+) without difficulty.

Key SAP inputs developers must get right

Getting SAP right early

The most expensive SAP mistake is running the assessment too late. Best practice is to run an indicative SAP assessment at the feasibility stage, using assumed specifications. At Electromatic, we work directly with SAP assessors to provide accurate heat pump performance data, solar PV yield estimates, and system specifications that feed into the SAP model.

Heat Pump Specification for New Builds

Specifying the right heat pump for a new build is different from retrofit. New buildings have lower heat demand (thanks to better insulation), but the specification must be coordinated with the SAP assessment, ventilation strategy, and hot water requirements.

Sizing

New build dwellings typically have much lower heat loss than existing buildings. A well-insulated three-bedroom semi-detached house might need only 4–6 kW of heating capacity, compared to 8–10 kW for a poorly insulated Victorian equivalent. Oversizing the heat pump wastes capital and reduces efficiency.

Heat loss calculations should be carried out using MCS MIS 3005 methodology for each dwelling type. For developments with repeated house types, a single calculation per type is sufficient.

Preferred system configurations

For new build developments, we typically recommend:

• Monoblock ASHP: Simpler installation with no F-gas handling required on site — important for programme efficiency on multi-plot sites
• R290 refrigerant models: Lower GWP refrigerant that aligns with FHS expectations and future regulatory direction
• Pre-plumbed cylinder packages: Factory-assembled heat pump and cylinder packages reduce on-site installation time
• Smart controls: Internet-connected controls that enable remote monitoring and support — reduces call-back rates

Hot water considerations

Every heat pump installation requires a hot water cylinder. In new builds, this needs to be designed into the layout from the outset — you need cupboard space for a 150–250 litre cylinder. Heat pump-optimised cylinders with large-surface-area coils ensure adequate hot water recovery rates and are essential for efficient operation.

Solar PV Requirements

Solar PV is now a de facto requirement for new build compliance, and the Future Homes Standard makes it effectively mandatory.

Sizing for SAP compliance

The PV array size needed depends on the dwelling type, heating system, and fabric specification. As a general guide:

• Part L 2021 with heat pump: 2–3 kWp per dwelling is typically sufficient
• Future Homes Standard: 3–4 kWp per dwelling may be needed depending on other specification choices

Roof design implications

Solar PV requirements should influence roof design from the outset:

• Orientation: South-facing roofs maximise yield; east-west splits provide a flatter generation profile
• Pitch: 30–40 degrees is optimal for UK latitudes
• Shading: Avoid overshadowing from adjacent buildings, dormers, or chimneys
• Structural loading: Modern PV panels add approximately 12–15 kg/m² — this needs to be accounted for in roof structure design

DNO applications

Solar PV installations above 3.68 kWp per phase require a G99 application to the local Distribution Network Operator (UKPN in our area). Applications should be submitted early — processing times can be 8–12 weeks.

MVHR and Ventilation

The Future Homes Standard’s airtightness requirements make mechanical ventilation with heat recovery (MVHR) the default ventilation strategy for most new dwellings. MVHR recovers heat from extract air (kitchens, bathrooms) and uses it to pre-warm incoming fresh air. This reduces the heating demand that the heat pump must meet, allowing a smaller heat pump to be specified.

MVHR requires ductwork throughout the dwelling, which must be coordinated with the structural design, electrical layout, and heat pump pipework. In new builds, this coordination is straightforward provided it is planned from the outset.

Planning Conditions

Many local planning authorities now impose conditions related to energy performance and renewable energy on new developments. Common conditions include:

• Minimum percentage of energy from renewable sources (typically 10–20% on-site generation)
• BREEAM or equivalent sustainability assessments for larger developments
• EPC A requirement as a planning condition (increasingly common in London boroughs)
• Electric vehicle charging provision (often bundled into the energy strategy)
• Overheating assessments demonstrating compliance with Part O

Building Control Sign-Off

Building control sign-off for energy performance requires:

• As-built SAP assessment reflecting the actual installed specification
• Commissioning certificates for the heat pump, confirming correct operation and performance
• MCS certificate for the heat pump and solar PV installations
• Airtightness test results for each dwelling
• Ventilation commissioning records (flow rates for MVHR or mechanical extract)
• EPC generated from the as-built SAP assessment

At Electromatic, we provide all commissioning documentation, MCS certificates, and performance data needed for building control sign-off.

What This Means for Your Development Costs

Heat pumps and solar PV add cost to each dwelling compared to a traditional gas boiler specification. However, the context matters:

• Gas boilers are no longer the baseline — under Part L 2021, the compensatory measures needed to pass SAP with a gas boiler often cost more than simply specifying a heat pump
• BUS Grant: Each qualifying dwelling with a heat pump may access a £7,500 BUS Grant (subject to eligibility criteria set by Ofgem)
• EPC A premium: Properties with EPC A ratings command a measurable price premium — typically 5–15% according to recent market data
• Green mortgage products: Buyers with EPC A properties can access preferential mortgage rates, widening your potential buyer pool

For a typical three-bedroom new build, the net additional cost of a heat pump and solar PV package is often in the range of £2,000–£5,000 per plot. Against a selling price of £400,000+, this is a marginal investment with significant marketing and compliance returns.

Frequently Asked Questions

Can I still install gas boilers in new builds in 2026?

Under Part L 2021, gas boilers are technically still permitted, but achieving compliance is very difficult and typically more expensive than specifying a heat pump due to the compensatory measures required. Under the Future Homes Standard, fossil fuel heating in new dwellings is explicitly prohibited. For all practical purposes, heat pumps are now the standard specification for new builds.

How does the BUS Grant work for new build developments?

The BUS Grant (subject to eligibility criteria set by Ofgem) provides £7,500 towards the cost of each heat pump installation. For new builds, the grant can be claimed provided the property has an EPC and the installation is carried out under MCS certification. The timing of the claim depends on ownership — the grant is typically claimed by the first owner after completion. Electromatic handles the full BUS Grant application process for every installation.

What SAP score do I need for an EPC A rating?

An EPC A rating requires a SAP score of 92 or above. With an air source heat pump (SCOP 3.5+), 3 kWp of solar PV, and Part L 2021-compliant fabric, most new build house types will achieve SAP scores of 92–98, comfortably securing EPC A.

Do I need MVHR in every new build dwelling?

Under Part L 2021, MVHR is not mandatory but improves the SAP rating and is increasingly recommended. Under the Future Homes Standard, the combination of very high airtightness requirements and the need for a 75–80% carbon reduction makes MVHR the default ventilation strategy for most dwelling types.

How early should I engage a heat pump installer for a new development?

As early as possible — ideally at the feasibility or RIBA Stage 2 design phase. Early engagement allows the heat pump and solar PV specification to inform the SAP assessment, architectural design (cylinder cupboards, roof orientation, plant room space), and cost plan. Late engagement almost always results in design changes and programme delays.

Developer Consultation

Whether you are planning a single plot or a 50-unit development, understanding and meeting new build heat pump requirements is essential for compliance, programme efficiency, and sales success.

Request a developer consultation →

Call us: 07718 059 284 | Email: admin@electromatic.uk

We provide SAP input, system design, pricing, and full installation services for new build developments across London and Surrey.

The information in this article is for general guidance only and does not constitute legal, regulatory, or commercial advice. Building regulation requirements are correct as of April 2026 and may be subject to legislative change. SAP score estimates are indicative and depend on the specific dwelling specification. The Boiler Upgrade Scheme (BUS) grant of £7,500 is subject to eligibility criteria set by Ofgem — not all properties qualify. Electromatic M&E Ltd operates under MCS certification via our accredited umbrella partner. All installations comply with Building Regulations Part L and MCS standards. E&OE.

Written by Electromatic M&E Ltd — ASHP & Solar installer, London & Surrey (electromatic.uk)

Last updated: April 2026 | Electromatic M&E Ltd, Company No. 13837345