What Is MVHR and Do You Need It for Your Eco‑Home?

If you’re designing or renovating a home with energy efficiency in mind, you’ll likely be thinking about insulation, airtightness and how to reduce heat loss. But there’s one question that often gets overlooked: How do you keep the air fresh without opening windows and losing all that lovely warmth?

That’s where MVHR comes in. Short for Mechanical Ventilation with Heat Recovery, it’s a whole-house system designed to provide continuous balanced ventilation without wasting energy. For homes built to be airtight and super-insulated, MVHR is often the missing piece of the puzzle.

So, what is MVHR?

An MVHR system removes stale humid air from rooms like your kitchen, bathroom and utility and replaces it with fresh filtered air. But unlike traditional ventilation, it doesn’t just chuck the warm air outside. Instead, it captures the heat from that outgoing air and uses it to warm up the incoming air. The result? Cleaner indoor air with very little energy waste.

Everything happens quietly in the background through a network of concealed ducting. It’s a centralised system meaning you don’t have noisy fans in every room and the indoor temperature stays consistent all year round. If you’ve ever lived in a new or well-insulated home that felt a bit stuffy or suffered from condensation and black mould, MVHR solves that problem at the source.

How does it work in practice?

Inside an MVHR unit is a clever bit of kit called a heat exchanger. As the stale air is extracted from your wet rooms, the system captures the heat from it and uses that to warm the fresh air being brought in from outside. The two airflows never mix but the heat is transferred efficiently between them.

This warmed filtered air is then gently supplied to your living spaces - bedrooms, lounges, home offices - creating a constant cycle of fresh air without letting the heat escape. The system runs 24/7 and it does so surprisingly quietly. Many homeowners say they only notice it when it’s turned off.

Why is MVHR a good fit for eco-homes?

MVHR systems work best in homes that are well-sealed and highly insulated where natural air leakage is minimal and opening a window can undo all your hard-earned energy savings. If you’re building a new home to Part L or Passive House standards or if you’re retrofitting with high-spec insulation and triple glazing, then MVHR is often recommended.

Beyond the efficiency, the comfort factor is a big selling point. There’s no more need to open windows on cold winter mornings just to stop your home from feeling stuffy. You get fresh air in every room without any draughts or heat loss. The filters also remove dust, pollen and pollutants making it a great option for allergy sufferers, pet owners or anyone sensitive to air quality.

Another bonus?

It helps control moisture. Because the system constantly removes humid air, it significantly reduces the risk of condensation, mould and damp - particularly in modern homes where moisture has nowhere to escape.

Can MVHR be retrofitted into older homes?Yes, but it’s not as simple as plugging in a fan. Retrofitting MVHR into an existing home takes planning and it’s usually most cost-effective when combined with a renovation. That’s because you’ll need space to run the ductwork (often in ceilings, floors or loft voids) and the home needs to be reasonably airtight for the system to work efficiently.

If your home has lots of draughts or poor insulation, MVHR won’t be as effective - it’ll be like trying to keep a bath full with the plug out. In those cases, it’s better to focus on improving the fabric of the building first. But if you’re already doing that or building from scratch, it’s well worth considering MVHR at the design stage. It’s one of those upgrades that’s hard to live without once you’ve had it.

What does it cost and is it worth it?

For a typical home, a full MVHR system (including design, supply and installation) can range from around £8,000 to £20,000 depending on the size of the property and complexity of the ducting. While that’s a significant investment, the long-term benefits - energy savings, air quality, moisture control and comfort - often make it worthwhile for homes aiming for high performance.

It’s also worth remembering that MVHR doesn’t replace your heating system - it works alongside it to reduce the amount of heat you need in the first place. That means your heat pump or boiler won’t have to work as hard, your home stays fresher and your indoor environment becomes more consistent and comfortable year-round.

So, is MVHR right for your home?

If you’re in the process of building, renovating or upgrading your home in Kent or Sussex and you want it to be future-proofed for energy efficiency, MVHR is well worth considering. It works best in homes that are well-insulated and airtight but if you’re not sure where your home stands, we’re happy to offer honest advice.

We’ll look at your building plans, your current setup and your energy goals to help you decide if MVHR is a smart fit. No pressure. No pushy sales. Just clear practical guidance based on what’s best for you and your home.

Looking to improve your indoor air quality without losing energy?Get in touch for a free consultation and find out if MVHR could work in your home.