What is passive construction?

A passive house does not heat. It conserves.

The idea is radical in its simplicity: instead of offsetting heat losses with a large heating system, you start by eliminating them. A very well insulated envelope, free of defects, captures solar heat and heat from the occupants — and retains it.

The result: a building that can do without conventional heating, or almost. The heat given off by occupants, electrical appliances and the sun is enough to maintain a comfortable temperature.

First passive house in France, 2006. Large south-facing windows, timber frame structure, louvre solar shading.

Five non-negotiable rules

The Passivhaus standard rests on five precise technical criteria. All five are required — one without the others is not enough. It is this overall coherence that guarantees performance.

Heat recovery ventilation (HRV) deserves particular attention: often misunderstood, it is inseparable from the passive standard. It continuously renews the air while recovering the heat from the extracted air — which avoids any loss due to ventilation.

First and foremost, a building that is pleasant to live in

The paradox of the passive house: in seeking to reduce energy consumption, what you get above all is remarkable comfort. No cold draughts near windows. No cold surfaces. Constant air quality.

The interior surface of the glazing stays above 17°C in the depths of winter — eliminating the cold-surface sensation typical of ordinary buildings.

20–22°C

Stable temperature in winter, no draughts

< 1 000 ppm

Indoor CO₂ — constant air quality

≥ 17°C

Interior glazing surface temperature in winter

40–60 %

Relative humidity — optimal comfort

How much does it consume?

Heating demand is measured in kWh per square metre per year. The comparison speaks for itself.

Space heating demand (PHPP indicator). The passive standard consumes roughly 10× less than an average existing building. Since reference floor areas (SRE) are calculated differently between Passivhaus (PHPP) and Minergie® (SIA 416), the values are indicative.

Two labels, one shared logic

In Switzerland, the passive standard is available under two labels. One is international — the Passivhaus Institut in Darmstadt — the other is Swiss: Minergie®-P. Their requirements are similar, with some differences in method.

* Reference energy floor areas (SRE) are calculated using different conventions between Passivhaus (PHPP, PHI Darmstadt) and Minergie® (SIA 416 standard). A direct comparison of the numerical thresholds is therefore approximate and does not necessarily reflect a real difference in requirements between the two labels. Minergie® values according to regulation 2026.1 (absolute minimum of 15 kWh/m²·an; airtightness q_E50 measured according to EN ISO 9972:2015 + SIA 180:2014).

EnerPHit: the passive standard for existing buildings

Retrofitting to the passive standard is possible, but the constraints of existing buildings — geometry, structure, unavoidable thermal bridges — call for adaptations. The EnerPHit standard (Passivhaus Institut) and Minergie®-P Rénovation define specific targets.

EnerPHit target : ≤ 25 kWh/m²·an, two to three times less than a conventional retrofit, with incomparable comfort.

Valid for any new build or high-performance energy retrofit: the logic of the five pillars remains the guiding thread.

Retrofit in progress: insulation and careful attention to envelope details determine the final performance.

What we often hear. And the reality.