Finally built my ultra-efficient dream home

That's awesome to hear - definitely worth the upfront investment. I've noticed similar results with clients who've gone heavy on insulation and sealing. Curious though, did you also go for a heat recovery ventilation system? Seen mixed opinions on whether they're worth it...

I’d qualify the idea that heat-recovery ventilation is generally worth it:

- In a genuinely airtight home, it can improve indoor air quality and reduce ventilation heat loss.
- In a leaky build, the energy-saving case is much weaker, since uncontrolled air exchange is already doing much of the ventilating.
- Climate matters too. The recovery benefit is more noticeable where heating or cooling loads are substantial.
- Filters, condensate drains, and balanced airflow need regular attention. Poor commissioning or neglected maintenance can mean noise, drafts, and disappointing performance.

So I wouldn’t treat it as an automatic upgrade alongside triple-pane windows and insulation. Airtightness testing and proper system design should come first.

The warning about poor commissioning leading to noise and drafts is the part I’d want to verify before judging the system. What measurements or checks would you use after installation to confirm that each room is getting its intended airflow without excessive pressure, noise, or drafts?

I’m thinking of balanced supply and extract readings, room-by-room airflow against the design figures, and an airtightness test, but I’m less sure which indoor-air-quality readings are most useful. Would CO₂ monitoring be enough for normal occupancy, or would you also check humidity, particulates, and possibly formaldehyde?

For commissioning, I’d compare the measured supply and extract flows room by room against the design figures, then check the overall balance. A smoke pencil or even a tissue strip at door gaps and grilles can also reveal pressure-driven drafts that the airflow numbers might miss.

CO₂ is useful for seeing whether ventilation keeps up with normal occupancy, but it won’t catch everything. Humidity trends can flag moisture problems, while particulate readings can show filtration or outdoor-air issues. Those measurements don’t need to become a costly permanent monitoring setup, either. A short baseline period after commissioning may be enough to spot problems before they turn into comfort or maintenance costs. What matters most is getting the readings under normal occupancy and with the system at its usual settings.