MVHR in New Builds – A Necessity for Modern Homes

Author:
Dr. Julian Carter

New homes in the UK are more airtight than ever. As building standards push for higher energy efficiency, the days of draughty walls and heat-leaking windows are gone. But with better insulation and low permeability comes a challenge: how to ventilate a home that no longer breathes.

Why MVHR Is Built Into the Future of UK Housing

New homes in the UK are more airtight than ever. As building standards push for higher energy efficiency, the days of draughty walls and heat-leaking windows are gone. But with better insulation and low permeability comes a challenge: how to ventilate a home that no longer breathes.

Mechanical Ventilation with Heat Recovery (MVHR) is now a key feature in modern home design. Not only does it meet new ventilation requirements under Part F and Part L of the Building Regulations, it also helps achieve SAP targets, supports EPC ratings, and improves indoor air quality.

At ClimateWorks, we design and install MVHR systems for new developments across Basingstoke, Woking, Reading, West London, and other growing urban hubs. In a market where energy ratings matter to both developers and homeowners, MVHR is not just a nice-to-have—it’s a necessity.

The Growing Need for MVHR in Modern Construction

Building Regulations in the UK are changing how homes are built. Tightened standards under Approved Document F (ventilation) and Approved Document L (energy conservation) mean that uncontrolled ventilation, such as window trickle vents or passive ducts, no longer satisfy compliance in most new builds.

When a home achieves air permeability under 5 m³/(h·m²) @ 50 Pa—which is common in new construction—it must use continuous mechanical ventilation, and ideally with heat recovery, to meet legal ventilation targets.

In other words, if you're building new homes that are well-insulated and airtight (as nearly all are), you need MVHR to comply with the law and provide proper indoor air quality.

UK Regulations That Support MVHR in New Builds

Part F: Ventilation

Part F of the Building Regulations sets out the minimum fresh air requirements for new dwellings. MVHR is listed under System 4, which requires:

  • Continuous supply and extract
  • Minimum whole-house airflow based on floor area and occupancy
  • Boost airflow in kitchens, bathrooms, and utility rooms
  • Commissioning to confirm flow rates match design

Systems must also meet noise performance, have accessible filters, and include controls that are user-friendly.

Read more about Part F here

Part L: Conservation of Fuel and Power

Part L requires buildings to conserve energy. MVHR supports this by recovering 85–90% of the heat from outgoing air, helping reduce the space heating demand and improving the Dwelling Emission Rate (DER).

New SAP 10 methodology includes the benefits of MVHR in its calculations, meaning it contributes to:

  • Lower energy bills
  • Better EPC ratings
  • Greater resale value for developers

Explore Part L details here

Case Study: MVHR Installation in a New-Build Development in Wokingham

A developer constructing 12 energy-efficient homes in Wokingham wanted to futureproof the properties for Part F compliance and sustainable performance. The build featured:

  • Air permeability below 3 m³/h·m²
  • Triple-glazed windows
  • No trickle vents
  • High fabric insulation (U-values below 0.14 W/m²·K)

ClimateWorks was brought in at the design stage to integrate MVHR into each unit. Our approach included:

  • Centralised heat recovery units in each loft
  • Semi-rigid radial ducting to ensure low resistance and minimal air leakage
  • Commissioning and flow testing in line with Approved Document F
  • Homeowner guides and handover packs

The result was full compliance, improved SAP scores, and greater long-term appeal for buyers focused on energy performance and air quality.

Why MVHR Is the Preferred Option in New Builds

While extract-only fans may be suitable for older homes, they fall short in new builds with high levels of airtightness. MVHR systems are now the go-to option for high-performance new homes due to their:

  • Consistent indoor air quality
  • Energy-saving heat recovery
  • Reduction in condensation and mould risk
  • Compliance with current and future regulations

Benefits of Installing MVHR in New Builds

Performance Benefits:

  • Supplies filtered, fresh air to living areas and bedrooms
  • Extracts stale, moist air from kitchens and bathrooms
  • Recovers heat from exhaust air
  • Balances pressure across the house
  • Operates continuously and quietly

Compliance Benefits:

  • Fully satisfies Part F mechanical ventilation standards
  • Supports Part L energy efficiency targets
  • Helps developers meet SAP and EPC requirements

How ClimateWorks Supports Developers and Builders

Installing MVHR is not a plug-and-play job. We offer end-to-end services that ensure every unit is installed and commissioned in line with Building Regulations and site-specific goals.

Our services include:

  • Ventilation design at RIBA Stage 3 or earlier
  • System sizing based on SAP targets
  • Full installation by F-Gas and BPEC certified engineers
  • Commissioning and flow testing with documentation for Building Control
  • Homeowner support and servicing plans

We currently install MVHR systems in new homes across:

  • Basingstoke
  • Woking and Wokingham
  • Reading and Newbury
  • West London

Our familiarity with local Building Control teams ensures your project moves forward without costly delays or compliance failures.

MVHR Installation Checklist for New Builds

✔ Has airtightness been measured or modelled?
✔ Are there trickle vents or passive vents?
✔ Will the property meet SAP 10 energy standards?
✔ Are duct routes planned into floor or ceiling voids?
✔ Is the system specified and sized for the property?
✔ Has commissioning been scheduled as part of the build programme?

If the answer to any of these questions is unclear, MVHR should be addressed at the earliest design stage—not left to the final fitout.

Looking for MVHR Installers for New Builds?

We install and commission MVHR systems across the South East. If you're developing homes in Hampshire, Berkshire, Surrey or Greater London, we can help you:

  • Meet all regulatory targets
  • Improve SAP and EPC ratings
  • Deliver a better product to your customers

👉 Contact ClimateWorks to discuss your new build project

Explore the benefits of working with certified MVHR specialists from design to handover.

References

[1] GOV.UK – Approved Document F: Ventilation
https://www.gov.uk/government/publications/ventilation-approved-document-f

[2] GOV.UK – Approved Document L: Conservation of Fuel and Power
https://www.gov.uk/government/publications/conservation-of-fuel-and-power-approved-document-l

[3] NHBC – Mechanical Ventilation with Heat Recovery in New Homes
https://www.nhbcfoundation.org/publication/mechanical-ventilation-with-heat-recovery-in-new-homes/

[4] Energy Saving Trust – Whole House Ventilation
https://energysavingtrust.org.uk/advice/ventilation/

Author Bio

Dr. Julian Carter is a highly experienced thermal systems expert with over 15 years in the field, holding a PhD in thermal systems. His career spans academic research, consulting, and teaching, focusing on air conditioning and refrigeration systems. Dr. Carter bridges the gap between theoretical advancements and practical applications, providing expert insights to organisations like ClimateWorks, where his guidance informs decision-making and industry best practices. Notably, he has worked on international projects with organisations such as Daikin Industries, the International Institute of Refrigeration (IIR), and the United Nations Environment Programme (UNEP). Currently a lecturer at Edinburgh University, Dr. Carter combines his expertise with a passion for educating the next generation of engineers and advancing climate control technologies.

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