Heat pumps and the Future Homes Standard — what new build heating looks like from 2027 — UK new build solar PV installation
Future Homes Standard

Heat pumps and the Future Homes Standard — what new build heating looks like from 2027

Air source heat pumps are the default heating for FHS-compliant new dwellings. We explain ASHP sizing, the integration with solar PV, hot water cylinder requirements and the SAP/HEM impact.

FHS Heat Pump Requirements for New Builds — Future Homes Standard guidance for new builds

Heat pumps are not strictly mandated under Part L 2026, but they are the only realistic compliance route given the carbon targets. From 24 March 2027 the great majority of new dwellings in England will use air source heat pumps.

Why ASHPs dominate FHS-compliant heating

Air source heat pumps deliver ~3 kWh of heat per kWh of electricity (Seasonal Coefficient of Performance of 3.0 typical). Combined with the low-carbon grid this delivers ~0.03 kgCO₂/kWh of heat — versus 0.21 kgCO₂/kWh for natural gas. ASHPs are the only widely-deployable technology that hits the FHS targets.

Sizing rules

Heat pump output is sized to peak heat loss at the -2°C (or local design temperature) external condition. Typical sizing for an FHS-compliant 3-bed semi: 5–6 kW ASHP. 4-bed detached: 6–8 kW. The hot water cylinder needs to be sized to ~180–250L depending on bedroom count.

Integration with solar PV

Solar-paired ASHPs run efficiently when the sun shines — and HEM models this self-consumption explicitly. A 5 kWp solar array paired with a 6 kW ASHP and a 5 kWh battery is the FHS notional building for a typical 3-bed semi.

Cylinder requirements

Hot water cylinders for ASHP must be larger and lower-pressure than gas-fired equivalents. Typical specification: 180L unvented cylinder for a 3-bed, 200L for a 4-bed. Pre-plumb for solar thermal is not required (PV diverter to immersion is more cost-effective).

Cost and supplier ecosystem

ASHP units from Daikin, Mitsubishi Ecodan, Vaillant aroTHERM, Samsung EHS and Grant Aerona are widely available at volume. Bulk procurement pricing for developers runs £2,200–£2,800 per system installed.

40% of ground floor area
PV / ground floor area
Mar 2027
FHS in force
75%
CO₂ vs 2013 baseline
£4,350 per dwelling
Per-plot premium
For developers and housebuilders

Fhs heat pump requirements for new builds for volume new-build programmes

Per-plot pricing locked at procurement. Factory pre-fit on panelised roof cassettes. SAP/HEM modelling for every house type included. NHBC, LABC, Premier and Buildmark warranty-accepted workmanship. 20-year insurance-backed system warranty. We work with developers from 50 plots to 5,000+ across multi-site frameworks — agreed pricing, agreed programme, agreed warranty stack.

For self-builders and architects

Fhs heat pump requirements for new builds for one-off custom builds

Engagement from RIBA Stage 2. PV sizing collaborative with the architect. SAP/HEM modelling that gives the architect freedom on glazing ratios and roof geometry. Building Control submission pack ready for the Approved Inspector. 0% VAT on new-build dwellings. Staged invoicing aligned to your self-build mortgage drawdowns. We work with custom-build buyers across England, Wales and Scotland.

How this fits into the FHS compliance pathway

Every FHS-compliant new build must pass three regulatory gates. Fhs heat pump requirements for new builds fits primarily into the second gate — design-stage Part L compliance — but has knock-on implications for Building Control sign-off and post-completion warranty:

  1. 1
    Planning permission Most solar PV on new dwellings is consented within the dwelling\'s primary planning consent. Conservation Areas, Article 4 directions and listed-curtilage plots require additional planning consideration — we handle the planning evidence required for these.
  2. 2
    Building Control — Part L compliance SAP 10.3 or HEM compliance modelling demonstrating Dwelling Emission Rate ≤ Target Emission Rate. PV specification, ASHP capacity, fabric U-values and air permeability all entered into the modelling. We provide the full compliance file ready for the Approved Inspector.
  3. 3
    Post-completion — warranty & EPC MCS certificate, EPC, monitoring app onboarding and 20-year insurance-backed workmanship warranty. NHBC, LABC, Premier and Buildmark all accept our installation specification without query — important if you\'re relying on a structural warranty for buyer mortgageability.

For a fuller walkthrough of the compliance process, see our Part L 2026 page and the FHS PV calculator which sizes a compliant system from your ground floor area in 30 seconds.

Frequently asked

Common questions

Answers to the questions we get most often when discussing fhs heat pump requirements for new builds with new clients.

When does the Future Homes Standard come into force?
24 March 2027 in England, with a 12-month transitional period running to 24 March 2028 for projects already under construction. The Approved Documents L and F were published on 24 March 2026 (Government statement HCWS1445), giving the industry exactly 12 months of certainty before regulatory commencement. Scotland, Wales and Northern Ireland are following with broadly equivalent regulations on roughly aligned timetables, although devolved nuances apply — Welsh regulations are typically 6 months ahead.
What does FHS-compliant solar PV actually cost per plot?
The Government Impact Assessment puts the total FHS premium at ~£4,350 per dwelling per dwelling (2025 prices, weighted average across heat pump, solar PV, MVHR and enhanced fabric). Of that, solar PV is roughly £4,200 — covering ~3.4 kWp for a typical 3-bed semi (panels, in-roof mounting, inverter, monitoring, MCS certification and 20-year insurance-backed warranty). Larger dwellings cost proportionately more; volume procurement reduces per-plot cost by 20–25%.
Will the 40% PV rule actually be enforced?
Yes — the rule is a functional requirement in the Approved Document, not guidance. Building Control sign-off requires SAP/HEM modelling demonstrating compliance. The previous Part L 2021 token "2-panel" systems no longer pass, since they fall ~85% below the 40% benchmark. The deemed-to-satisfy route requires the full 40%; alternative compliance through enhanced fabric is possible but rarely cost-effective.
Can I exceed FHS minimum specifications?
Yes — and many self-builders and premium developers do. Marginal capital cost of a larger array (e.g. 5 kWp instead of 3.4 kWp on a 3-bed) is only £1,000–£1,200, while the additional generation pays back in 3–4 years at 2026 electricity tariffs. Upgrades that fit easily on top of an FHS-compliant base include battery storage (£3,500–£5,000), larger array size, EV charge point pre-fit (£600) and air permeability below 2 (achievable with deliberate detail).
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