Make-up Air in Airtight Homes: What UK Households Need to Know

As UK homes become more airtight thanks to modern insulation and energy-efficient construction, many households are now hearing the term make-up air. But what does it actually mean—and do you really need it? This quick guide breaks it down in simple, practical terms.

What Is Make-Up Air and Why Does It Matter?

Every extractor fan in your home—especially your kitchen hob or cooker hood—removes air from indoors. In older draughty homes, external air naturally flows back in to balance things out. In newer, airtight homes, this replacement air has no easy path inside. That’s where make-up air comes in.

💡 Quick fact

A modern cooker hood can remove over 600m³ of air per hour.

💡 Quick fact

Without replacement air, extraction efficiency can drop by 30–50%.

Signs Your Home Might Need Make-Up Air

Most issues appear in the kitchen because that’s where powerful extraction systems are used most. Look out for these signs:

Cooker hood seems weak or noisy
Windows whistle or rattle when the hood is on
Smoke or steam lingers longer than expected
Back-draughts from fireplaces or stoves
Bathroom fans struggle to clear humidity

How UK Homes Usually Provide Make-Up Air

Even airtight homes have options. Common and effective solutions include:

Dedicated wall vents supplying fresh air
Trickle vents fitted to modern window frames
Mechanical ventilation with heat recovery (MVHR)
Recirculating hoods that clean air instead of extracting it
Smart vented hobs that manage airflow automatically

Do All UK Homes Need a Make-Up Air System?

No—not automatically. Most homes simply need a controlled way for fresh air to enter. The newer and more airtight the home, and the stronger the cooker hood, the more likely a make-up air solution is beneficial. New builds with MVHR may already be balanced.

A Simple Rule of Thumb

If your home was built after 2006 and you use a high-powered cooker hood or a vented hobA hob with an integrated extractor that pulls air downwards through a central vent., check whether enough replacement air is available—especially during heavy cooking.

Conclusion

Make-up air isn’t complicated—just overlooked. If your hood feels weak, the kitchen fills with steam, or fans struggle to clear moisture, you may simply need a better path for fresh air. A small fix can dramatically improve comfort and ventilation performance.