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Passive House: Your Essential Guide

Drew Barker
Marketing
Posted April 25, 2023

Over the coming weeks, we’re going to delve a little deeper into some of the concepts behind Passivhaus (or Passive House in English). In this series, we’ll explain what Passivhaus is, how it works and why it’s important. To kick things off, let’s start by defining what Passivhaus actually means and take a quick look at some of the benefits.

What is Passivhaus?

Simply put, Passivhaus is the gold standard of energy efficient design for buildings. Unlike traditional buildings, which require a conventional heating system, a Passive House, as the name suggests, is primarily heated (and cooled) by passive sources.

“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, the Passivhaus Institut

Passivhaus has become synonymous with remarkably low, or even zero heating bills, and rightly so. But energy efficiency is far from the only benefit, as we’ll find out later. Most people don’t realise it’s also a rigorous comfort and quality standard.

Passive Houses and energy efficiency

A Passive House needs as little as 10% of the energy consumed by a typical Central European building, making them exceptionally efficient. As the saying goes, the cheapest energy is the energy you don’t use, so you’ll be pleased to hear you could save up to 90% on your heating bills! Given recent events and the sky-high price of energy, this seems like a no-brainer. We’re always surprised to hear that people still choose to build any other way. All they’re doing is leaving themselves at the mercy of the energy companies, worsening the climate crisis, and adding to the huge surfeit of homes that will need to be retrofitted, at considerable cost, further down the line.

What is the Passivhaus approach?

Passivhaus is all about physics, but don’t worry, it’s not rocket science. The concept itself is very simple. This short video explains how it all works in well under two minutes.

What are the 5 Principles of a Passive House?

In a nutshell, the 5 principles of Passivhaus are: super-insulation, superior windows, no thermal bridging, airtight construction and mechanical ventilation. For a building to be considered a Passive House, it must meet strict criteria in terms of how much energy it uses for heating (and other purposes). In addition, the airtightness of a Passive House must be below a certain threshold (<0.6ACH@50pa, if you’re interested) and the building must maintain a consistent level of thermal comfort throughout the year.

Passivhaus is often described as a ‘fabric first’ approach because much of its success depends on the quality and performance of the building’s structural thermal envelope (or its ‘fabric’).

What are the benefits of a Passive House?

The benefits of Passivhaus include enhanced energy efficiency and reduced environmental impact, with higher standards of comfort, health and wellbeing. However, research conducted by the Passivhaus Trust has identified almost 50 benefits in 6 different categories, as shown below.

The many benefits of Passive House include energy efficiency, comfort and carbon-saving.

Is Passive House the same as Net Zero?

Not necessarily.

The distinction between these two terms is important and they should not be used interchangeably. Passivhaus is concerned with reducing a building’s energy consumption, while the term ‘Net Zero’ describes a building that generates as much energy as it consumes over a year.

Logic dictates that Net Zero is easier to achieve when a building is already highly energy efficient. This means a home built to Passivhaus standard is optimised for Net Zero. Our homes could be considered ‘Net Zero-ready’ because it only takes a little energy to balance out the remaining energy demand.

What is Passivhaus Plus?

‘Passivhaus Plus’ is a relatively new certification category that recognises the production of onsite renewable energy by passive buildings. It basically takes all the benefits of Passivhaus and then layers on renewable energy to achieve zero carbon. Our Net Zero modular housing project in Cardiff is a good example of this approach in practice. Photovoltaic panels are fitted on all the roof spaces to capture thermal energy from the sun, which is then converted into electricity.

Closing thoughts

Passivhaus is not just a buzzword or a passing trend, it’s a tried and tested energy efficient design standard that has already helped many buildings and homes achieve exceptional levels of energy efficiency. By focusing on the building’s thermal envelope, super insulation, airtightness, superior windows, and mechanical ventilation, Passivhaus not only reduces energy consumption, but also improves indoor comfort and air quality. It offers a clear path to zero carbon buildings, which will be a key part of hitting the UK’s Net Zero target by 2050.

Passivhaus also has the power to end fuel poverty, raise living standards and combat climate change. With rising energy costs and climate change concerns intensifying, it’s time for more people to embrace the Passivhaus standard and build homes that are truly sustainable and energy efficient. At Beattie Passive, our aim is to make Passivhaus more accessible, to more people, so nobody has to pay over the odds to heat their home.

Keen to learn more about Passivhaus and Net Zero housing? Give our team a call on 01953 687332 or email enquiries@beattiepassive.com.

We’re the experts in all things Passivhaus!