Passive House represents a revolutionary approach to energy-efficient building, offering an innovative method for residential construction that prioritises thermal comfort and affordability. Delve into the history, principles, and applications of this pioneering concept, and learn how Zehnder's contributions are leading the way in the UK's Passive House movement
Passive House is a construction concept, not a brand name. It stands for a building standard that is energy efficient, comfortable and affordable. It provides paramount thermal comfort with very low heating demand.
The Passive House standard was conceived when Professor Bo Adamson of Lund University, Sweden, and Dr. Wolfgang Feist of the Institute for Housing and the Environment, Germany, collaborated in 1988. The very first pilot project (the Kranichstein Passive House in Darmstadt, Germany in 1990) was Europe’s first inhabited multi-family home to achieve a recorded heating energy consumption of below 12kWh/(m2a) – just 10% that of the standard house at the time. This consumption level was confirmed via years of detailed monitoring.
In short, the heating system. A Passive House doesn’t need to be actively heated because it uses passive heat gains to heat itself. Consequently, only a minimal amount of additional heating needs to be supplied. The concept is based on excellent thermal insulation and a highly efficient heat recovery system. The heat stays indoors and, therefore, doesn’t need to be provided by an active system.
The ‘passive’ principle is well known in engineering. Passive security, passive filters, passive cooling and Passive House are examples of successful implementations of this principle. Of course, minor intervention is inevitable which means that these applications are not strictly ‘passive’ in the true sense of the term. Rather than simply allowing it to happen, processes are controlled in such a way that the required goals are met with minimum effort, as if it were happening all by itself.
In a passive house, where energy efficiency is a top priority, the principle of "Built tight – ventilate right" is fundamental. These homes are constructed to be exceptionally airtight, drastically reducing heat loss. However, this airtightness also limits natural airflow, making a mechanical ventilation system essential—not optional.
A well-designed ventilation system ensures a continuous supply of fresh, filtered air, which is vital for maintaining high indoor air quality. This is especially important because we spend up to 90% of our time indoors, where air can be up to five times more polluted than outside.
By ensuring a steady exchange of air without energy loss, ventilation systems in passive houses create a healthier, more comfortable living environment—quiet, draft-free, and always fresh.
