What does Passivhaus actually mean? And what are the benefits?

Over the coming weeks, we're going to delve a little deeper into some of the concepts behind Passivhaus. To kick things off, let's start by defining what Passivhaus actually means and then we'll take a quick look at some of the major benefits.

What is Passivhaus?

Beattie Passive was the first company in the UK to be awarded Passivhaus certification for a complete build system (walls, roof and ground floor) by the Passivhaus Institute in Germany, who define it as:

Passivhaus [NOUN] pronunciation / pas?v?ha?s:

“… a building, for which thermal comfort can be achieved solely by post-heating or post-cooling of the fresh air mass, which is required to achieve sufficient indoor air quality conditions – without the need for additional recirculation of air”

The Passivhaus Institute, Germany

Simply put, it is the gold standard of energy-efficient design.

Passivhaus is a fabric-first method of construction, which delivers phenomenal thermal performance by maximising airtightness and reducing thermal bridging. Constructed around a sustainable timber frame, our build system makes a building draught-free - essentially eliminating heat loss - to create a structure with very low energy requirements. Heating comes from ‘passive’ sources, such as sunlight, emitted heat from electrical appliances and even body heat. As you can imagine, this approach has a profound impact on energy bills. In fact, Passivhaus buildings typically use up to 90% less energy.

A Mechanical Ventilation and Heat Recovery (MVHR) system is incorporated into the design to provide a continuous stream of fresh, filtered warm air. As a result, Passivhaus is healthier than traditional construction methods and free from humidity, mould, airborne pollutants, dust and allergens.

“With Passivhaus, building heat losses are reduced so much that hardly any heating is needed at all. The sun, the occupants, household appliances, and even the heat recovered from used air cover a large part of the heating demand. The remainder can often be provided by the ventilation system”

Dr Wolfgang Feist, Founder & Director of the Passivhaus Institute

This short video does an excellent job of explaining Passivhaus in quick and simple terms.

The 5 Principles of Passivhaus

The criteria for achieving Passivhaus design is stringent and the testing is rigorous. Our system can be used for new builds or retrofitted to existing buildings.

The 5 Fundamental Principles of Passivhaus

1. Thermal insulation
2. Passivhaus windows (ours are triple glazed)
3. Ventilation with heat recovery
4. Airtightness
5. Thermal bridge-free design

The Key Benefits of Passivhaus

The benefits of Passivhaus are compelling for new builds but also as a retrofitting solution (which is governed by the EnerPHit standard) to enable local authorities and housing associations to achieve their decarbonisation goals.

• Extremely low heating and cooling costs that are immune to rising energy prices – Passivhaus buildings typically use up to 90% less energy than traditional buildings.
• Fuel poverty – could become a thing of the past with Passivhaus, especially in the retrofit market.
• Carbon emissions – since almost no heat escapes and very little, if any, extra energy is expended on heating, carbon emissions are minimal.
• Superior indoor air quality – MVHR provides a continuous flow of fresh, warm air, while simultaneously removing airborne particles and allergens.
• Thermal comfort – Passivhaus buildings are characterised by consistent indoor temperatures throughout the year.

Passivhaus demands meticulous attention to detail, intelligent design and precise construction. A strict certification process ensures that what is designed is built, and what is built performs as designed.

For all questions and enquiries, call Beattie Passive on 01953 687332 or email [email protected]