Living in a High-Performance Home: How to Actually Run It

Because you have been trained by leaky houses. In a poorly sealed, poorly insulated home, heat escapes about as fast as you can produce it, so the sensible strategy is short intense bursts in the room you are occupying, and airing the place out when it gets stuffy. Every one of those habits is a rational response to a building that cannot hold anything.

A high-performance home behaves in the opposite way: it holds heat, it manages its own air, and it responds slowly and evenly. Run it with the old habits and you get odd results, an overheated lounge, a ventilation system switched off to save nothing, windows opened at the hottest moment of the day. Run it as designed and it looks after you almost entirely. Nothing here is complicated, it is just different.

This is the single most important habit and the one most often broken. Mechanical ventilation with heat recovery is designed to run continuously, quietly, in the background. It uses a small amount of electricity to move air, and it recovers most of the heat from the air it removes, so running it is close to free in energy terms and is what keeps the house fresh and the humidity where it should be (PHINZ).

People switch it off for two reasons: to save power, which saves almost nothing, or because they assume ventilation is only needed when the house feels stale. By the time a house feels stale the moisture and carbon dioxide have already built up. Set it and leave it. The one job it does ask of you is filters, which we come to below. The mechanics are in how MVHR works.

In a sealed, well-insulated home you are maintaining a temperature rather than recovering one, and that changes the technique entirely. A low, steady input keeps the whole house even, and because the fabric holds heat, it stays that way. Blasting a heat pump for two hours in the evening overshoots the room you are in, leaves the rest of the house behind, and is less efficient than simply not letting the temperature fall in the first place.

You will still have a heat source, and you will be surprised how rarely it runs. The most common report from owners after a first winter is not that the house is warm, it is that they stopped thinking about heating at all. The even temperature from room to room is what people notice most, since it removes the familiar business of shutting doors and heating one space.

The instinct on a hot day is to throw everything open. In a high-performance home that is usually wrong, because you are inviting hot air into a building that is holding a comfortable temperature. The better routine is to shade the glass before the sun reaches it, keep the house closed through the heat of the day, then open up in the cool of the evening and overnight to purge whatever heat has accumulated.

External shading matters far more than internal blinds, because it stops the heat before it gets through the glass rather than after. If summer comfort is a concern, that is a design conversation, and it is the one genuine risk in the standard, as covered in the Passive House myths.

Filters are essentially the whole maintenance story for the ventilation, on a schedule measured in months rather than weeks. A clogged filter makes the unit work harder while moving less air, which quietly undoes the thing you paid for. Put it in the calendar with the smoke alarm batteries and it will never be a problem.

As for the surprises, they are consistent. The quiet, because the same sealing that stops draughts stops noise. The absence of condensation on winter mornings, which people notice within days. The evenness, room to room and hour to hour. And the strange experience of a house that does not have a cold end. If something does feel off, a room warmer or cooler than the rest, raise it early rather than adapting to it; it is usually a commissioning or shading adjustment rather than a fact of life.

Four habits cover almost everything. Leave the ventilation running continuously. Heat gently and steadily rather than in evening bursts. In summer, shade early, stay closed through the heat and purge overnight. Change the filters on schedule. Open the windows whenever you feel like it, because you can, you simply no longer need to.

Give it a season and the house stops being something you operate and becomes something you just live in. If you are building with us in Nelson Tasman we walk owners through all of this at handover, because a well-built home run on old habits is the one way to be disappointed by it.