☀ Solar Panels for New Builds
Mechanical Ventilation with Heat Recovery (MVHR) under the Future Homes Standard — UK new build solar PV installation
Future Homes Standard

Mechanical Ventilation with Heat Recovery (MVHR) under the Future Homes Standard

The new 3 m³/(h·m²) air permeability target means most FHS-compliant dwellings need MVHR to manage indoor air quality. We explain the system, the costs and the integration with PV+ASHP.

MVHR & Ventilation Under FHS Approved Document F — Future Homes Standard guidance for new builds

Approved Document F 2026 — published alongside Part L on 24 March 2026 — governs ventilation in new dwellings. Combined with Part L's tightened air permeability target of 3 m³/(h·m²), MVHR becomes effectively required for the majority of FHS-compliant homes.

Why MVHR becomes effectively required

At 3 m³/(h·m²) air permeability — less than half the legacy maximum of 8 — natural and trickle ventilation strategies struggle to deliver adequate fresh-air rates without overventilating. MVHR (mechanical ventilation with heat recovery) extracts stale air from wet rooms, supplies fresh air to bedrooms and living rooms, and recovers ~85% of the heat from the extract air.

How MVHR integrates with the FHS spec

MVHR runs continuously on low power (~30W). Combined with the larger solar array specified for FHS, the system frequently runs on excess PV — adding to self-consumption and improving the SAP/HEM score. The fresh-air supply also supports the larger glazing areas typical of modern designs without overheating.

Cost

A typical 3-bed MVHR installation (Vent-Axia Sentinel Kinetic, Nuaire MRXBOX or Zehnder ComfoAir) installed costs £2,400–£3,200. Larger 4-bed and 5-bed systems run £2,800–£3,800. The £2,800 line item in the FHS Impact Assessment matches this range.

Commissioning and Part F requirements

Approved Document F requires post-installation commissioning with airflow measurements at every grille. Many MVHR installations fail commissioning at first attempt due to ductwork compromises during the build. We coordinate MVHR installer commissioning with main contractor handover.

Alternative ventilation strategies

Decentralised mechanical extract ventilation (dMEV) systems remain compliant on smaller dwellings where the air permeability can be brought to ~4–5 m³/(h·m²). Passive stack ventilation is now rarely viable. MVHR is the dominant new-build solution from 2027.

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

Mvhr & ventilation under fhs approved document f 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.

Developer hub →
For self-builders and architects

Mvhr & ventilation under fhs approved document f 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.

Self-build hub →

How this fits into the FHS compliance pathway

Every FHS-compliant new build must pass three regulatory gates. Mvhr & ventilation under fhs approved document f 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 mvhr & ventilation under fhs approved document f 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).
Calculate your plot

FHS PV Calculator

Enter your ground floor area — get the 40%-rule minimum kWp, panel count and indicative cost in 30 seconds.

Open calculator →
Get costed

Free fixed-price quote

Plot details, postcode and target start-on-site — we return a fully-costed FHS-compliant package within 48 hours.

Request quote →

More on the Future Homes Standard

The 40% Ground Floor Area PV Rule Explained →

Part L 2026 requires solar PV coverage equal to 40% of the ground floor area. We break down exactly what that is, how to calculate it for any house type, and when the rule can be relaxed.

Future Homes Standard 2026 / 2027 Timeline →

The complete FHS rollout timeline — from the 24 March 2026 publication of the Approved Documents through to the 24 March 2028 end of the transitional period. Includes practical milestones for developers.

Gas Boiler Ban in New Builds: 2027 Rules →

From 24 March 2027 the Future Homes Standard makes gas, oil, LPG and hydrogen-ready boilers non-compliant in new dwellings. We explain why, what replaces them, and the impact on plot pricing.

FHS U-Values for Walls, Floors, Roofs & Windows →

Every U-value change under Part L 2026: external walls down to 0.15, ground floor to 0.11, roof to 0.11, doors to 1.0, air permeability to 3. With practical buildup examples.

FHS Cost Impact: £4,350 Per Dwelling Decoded →

The Government Impact Assessment estimates an average £4,350 per dwelling FHS premium. We break it down by line item (solar PV, ASHP, MVHR, fabric, doors) and show how it varies by house type.

FHS Transitional Period: What Pre-2027 Projects Can Do →

Projects that commence Building Control approval before 24 March 2027 may complete to Part L 2021 standards until 24 March 2028. We explain the rules and the practical implications.
FHS 2027 deadline approaching

Get an FHS-compliant solar quote in 48 hours

Tell us your plot details — ground floor area, location and target start-on-site date. We return a fully-costed system sized to Part L 2026 (40% PV rule), with the SAP/HEM compliance pack included.

Get my free quote Try the FHS calculator 📞 0330 088 5421