MVHR for Self-Build Projects: Meeting UK Standards from the Ground Up

Building Your Own Home? Ventilation Now Comes with Legal Responsibilities

Self-build homes offer the chance to create something perfectly tailored—space, layout, materials, and energy performance. But with freedom comes responsibility. UK regulations for ventilation and energy use are stricter than ever. Getting it wrong can lead to failed building inspections, delays in completion, or long-term issues like condensation, poor indoor air quality, and mould.

Mechanical Ventilation with Heat Recovery (MVHR) systems provide a fully compliant solution for fresh air delivery and heat retention—critical in today’s airtight homes. From a design and legal perspective, MVHR should be treated as essential infrastructure, not a luxury add-on. Especially in new homes built to meet or exceed Building Regulations Parts F and L, installing a professionally designed and commissioned MVHR system is now expected.

This guide outlines what every self-builder in the UK needs to know about integrating MVHR—from regulatory obligations to practical steps, costs, and long-term value.

The Growing Need for MVHR in Self-Build Projects

Most self-builders aim for above-average insulation, airtightness, and energy savings. These objectives are admirable—but they also eliminate the natural airflow older homes relied on. Airtight construction traps humidity and airborne contaminants indoors, which leads to:

• Stale, unpleasant air
• Damp and mould problems
• Higher risk of condensation damage
• Reduced comfort and indoor health

MVHR systems solve all of this by continuously supplying fresh filtered air, extracting stale air, and recovering up to 90% of the heat in the process. For self-builders targeting Passivhaus, low-energy, or net-zero homes, MVHR isn’t just suitable—it’s the only option that truly fits the build quality.

MVHR and Building Regulations: What You Must Comply With

Part F – Ventilation

Approved Document F requires a minimum amount of continuous ventilation in all new dwellings. MVHR is classified under System 4 in this document and must:

• Provide whole-house ventilation
• Use balanced airflow (supply and extract)
• Operate continuously
• Be commissioned to verify performance

Systems must meet specific airflow targets depending on your home’s size and layout. Ductwork must be designed to minimise resistance and noise.

Read Part F requirements here

Part L – Energy Conservation

To pass your SAP 10 or EPC assessment, you'll need to minimise energy losses. MVHR systems help reduce heating demand by recovering waste heat from extracted air.

High-performance units that meet Passivhaus certification standards can boost your SAP scores while delivering consistent airflow.

Part L details here

Case Study: Self-Build MVHR Installation in Andover, Hampshire

A homeowner in Andover contacted ClimateWorks during the early design stages of a five-bedroom detached property. The home was planned with:

• Triple-glazed windows
• Mechanical underfloor heating
• High-level insulation in floors, walls, and roof
• Airtightness target: below 3 m³/(h·m²)

We designed and installed an MVHR system using a central unit mounted in the plant room, with radial semi-rigid ductwork routed through ceiling voids. The system included:

• Summer bypass functionality
• F7 filters for pollen control
• Commissioning and balancing in line with Part F
• User training at handover

The homeowner passed building control, received high SAP scores, and noticed a significant improvement in indoor air freshness compared to previous homes.

Why Self-Builders Should Plan MVHR Early

Planning your MVHR installation at the start of your project makes everything easier and cheaper. Leaving it until after plasterboarding often results in:

• More difficult duct routing
• Limited access to ceiling or floor voids
• Compromised performance
• Higher costs for remedial works

By discussing MVHR during your architectural and M&E design stages, you’ll allow:

• Efficient layout of ductwork
• Space for silencers, filters, and unit placement
• Easier commissioning and long-term maintenance
• Cleaner installation with less disruption

Bullet Summary: What Every Self-Builder Needs for MVHR Compliance

• Design airflow rates per floor area and occupancy
• Specify low-resistance ductwork and quiet fans
• Ensure all components are accessible for maintenance
• Provide full commissioning and handover documentation
• Install user-friendly controls with occupant guidance
• Verify performance with air testing and documentation for Building Control

Costs and Considerations for Self-Build MVHR

MVHR systems typically cost between £2,000 and £5,000 for a full home installation, depending on property size and complexity. You should budget for:

• Unit cost (typically £900–£2,000)
• Ducting and silencers
• Installation labour
• Commissioning and sign-off
• Optional extras like Wi-Fi control or CO₂ sensors

Running costs are low—well-designed MVHR units consume around 25W–60W during operation, similar to a light bulb, and annual filter replacement costs are minimal.

Where We Install: ClimateWorks MVHR for Self-Builders

We install fully compliant MVHR systems in self-build projects across:

• Basingstoke
• Woking
• Newbury
• Wokingham
• West London
• Surrounding towns and villages in Hampshire, Berkshire and Surrey

Our in-house design team ensures your system is right from the start. Our engineers complete full installations and final commissioning to meet all Building Control requirements.

👉 Request your MVHR self-build quote here

References

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

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

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

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

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.

‍