What is Passivhaus?

In 1988, German physicist Dr Wolfgang Feist and his colleague, construction engineer Bo Adamson, started to research the idea of a ‘house without heating’. Fast forward to today and this concept, now named Passivhaus, has grown to become the de facto standard for low energy buildings. Passivhaus is an entirely voluntary standard. At Beattie, we build to the requirements of the Passivhaus standard every time, but it is up to you to decide if you would like your project to be officially recognised as a Passivhaus by an accredited certifier.

Founded by Dr Wolfgang Feist in 1996, the Passivhaus Institut (or PHI), is an independent research institute that has played a key role in the development of the Passivhaus concept. Our build system has been assessed and certified by the Passivhaus Institut. We should also mention the Passivhaus Trust, an independent non-profit organisation that promotes the adoption of Passivhaus in the UK.

The benefits of Passivhaus can be broadly defined as enhanced energy efficiency, reduced environmental impact and improved comfort, health and wellbeing. Research conducted by The Passivhaus Trust has identified almost 50 benefits in 6 different categories, as shown below.

Did you know a Passivhaus needs as little as 10% of the energy used by a typical central European building for space heating and cooling each year? As you can imagine, this has a profound impact on energy bills and carbon emissions.

• You could save a small fortune on your heating bills
• You’ll be doing your part to combat climate change

Passivhaus heating bills can be astonishingly low. So low, in fact, that it can even be deployed as a preventative measure against fuel poverty. Tenants in social housing, for example, are far less likely to default or get into arrears with their rent if they live in Passivhaus standard accommodation (Energy Saving Trust, July 2022).

It’s no exaggeration to suggest that Passivhaus can put an end to fuel poverty. And although Passivhaus is not an environmental standard per se, it can significantly reduce carbon emissions – more on that later.

Passivhaus is based on 5 key principles.

1. The Beattie Passive Build System create a continuously insulated structural thermal envelope.
2. We specify triple-glazed windows
3. We specify Mechanical Ventilation with Heat Recovery (MVHR)
4. We achieve Passivhaus standards of airtightness
5. Our build system is free of thermal bridges

To comply with the Passivhaus standard, the maximum demand for annual heating energy must not exceed 15 kWh/(m²a).

Passivhaus properties are naturally eco-friendly because they emit less carbon than traditional buildings and have a greatly reduced environmental impact. At Beattie, we take our environmental responsibilities very seriously and we build in a sustainable way, using timber, to reduce embodied carbon.

Energy efficiency and sustainability are not the only advantages of Passivhaus. In our experience, when people actually live in a Passivhaus, they learn to appreciate the comfort, health and wellbeing benefits just as much as the energy efficiency.

As a nation, we spend almost 90% of our time indoors, yet many of our interior spaces, at home and at work, are neither comfortable nor healthy. Passivhaus helps to maintain a comfortable environment throughout the year, with stable ambient temperatures, warm surfaces and no draughts, moisture, humidity, damp or mould. A highly efficient and inexpensive Mechanical Ventilation and Heat Recovery (MVHR) system provides a constant flow of fresh, warm air, while removing stale air, odours, airborne particles, pollutants and allergens.

There are actually four different classes of Passivhaus for new builds. In addition to the ‘Classic’ version of Passivhaus, there are two additional standards, Passivhaus Plus and Premium, that incorporate renewable energy. Buildings which do not fully conform to Passivhaus criteria may still satisfy the requirements for the PHI Low Energy Building Standard.

The other certification, EnerPHit, is the Passivhaus standard for your retrofit, refurbishment and remodelling projects. Like Passivhaus, it also has three classes depending on how you incorporate renewable energy. And despite the slightly higher energy demand, it offers virtually all the benefits of the Passivhaus standard.

We can’t talk about Passivhaus and Net Zero without talking about retrofit. Given that 80% of the buildings that we will use in 2050 have already been built, constructing new homes is simply not enough. We must decarbonise our existing housing stock, and we must do it now.

We can make your home more energy efficient, more comfortable and more environmentally-friendly. Give our team a call today.