We often wax lyrical about the health and comfort benefits of Passivhaus, but the original motivator for this construction method also stemmed from worldwide environmental concerns and affordability.
‘Passive house (German: Passivhaus) is a rigorous, voluntary standard for energy efficiency in a building, reducing its ecological footprint. It results in ultra-low energy buildings that require little energy for space heating or cooling’.
Dr Wolfgang Feist, along with Bo Adamson, are the originators of the Passivhaus Concept. Dr Feist is also the founder of the Passive House Institute which, as well as leading research into energy efficient design and components, created the energy modelling programme PHPP. This programme allows designers to view how their building design will perform in its unique location, and enables adjustments to the design to ensure it performs as intended, and is able to meet the Passivhaus standards.
The Passivhaus approach addresses financial and environmental issues
In the 1970s, Dr Feist was working on how to meet the growing demand for energy in the world. He found there was huge potential to use energy more efficiently instead of producing more energy.
The cost of energy had increased worldwide to the point that a lot of people were, and still are, having problems paying their heating bills.
Also, more than 80% of the energy being used worldwide, comes from fossil fuels. The consequences of emitting this level of carbon dioxide into the earth’s atmosphere means we really need to change the way we use energy and reduce our carbon footprint.
Passivhaus buildings are low energy buildings. Their energy consumption for heating is typically one tenth of that of a conventional building. The energy you need is so low that it could be supplied by regional sources of renewable energy anywhere in the world, reducing the need to import and use fossil fuels. This is one of the reasons why the European Commission supports Passivhaus.
The Passivhaus Institute
The International Passive House Institute is an independent research facility that influences construction by showing industry and government what can be done, helping to bring improved components to the market place, and helping affiliate organisations around the world to gain members, to gain knowledge and to make that knowledge available.
The Passivhaus Institute also produces tools for architects and engineers to make it easier for them to design an energy efficient building of this calibre.
The Passivhaus method doesn’t state the building style or type, and you can use any kind of material. As long as the combination of materials, coupled with the local climate data, produce a result that will meet the energy requirements of the standard then it can be called a Passivhaus
The Passivhaus standard
The Passivhaus standard provides a universal design method for achieving a good indoor environment. Although a Passivhaus in Stockholm may look significantly different from one in Canberra (as local climate will inform the design), the method for designing these buildings is the same.
The Passivhaus standard requires that the building meets the following requirements:
- The building must be designed to have an annual heating and cooling demand as calculated with the Passivhaus Planning Package of not more than 15kWh/m2 per year in heating or cooling energy OR be designed with a peak heat load of 10 W/m2.
- Total primary energy (source energy for electricity, etc.) consumption (primary energy for heating, hot water and electricity) must not be more than 120 kWh/m2
- The building must not leak more air than 0.6 times the house volume per hour (n50≤ 6 / hour) at 50 Pa as tested by a blower door.
As explained in a lot more detail in our earlier blogs, there are certain considerations that influence the energy balance of a Passivhaus building and so need to be factored into the design to reach the Passivhaus standard:
- Good insulation
- Avoidance of thermal bridging
- Window quality
Importantly, the Passivhaus certification provides assurance to buyers or sellers of Passivhaus buildings that they have been constructed properly and genuinely operate to this Passivhaus standard.
The Passivhaus standard isn’t just for new builds
Retrofitting of existing housing stock is harder. The key is to understand when it’s most efficient to make improvements. For example, if you have to do some maintenance to the roof, that’s the time to improve the insulation. You wouldn’t exchange a window just to save energy, you would upgrade an existing window at the end of its life. If you are going to improve a component then choose the best available because it will be 30-50 years until you do it again.
Non-financial incentives encourage adoption of the Passivhaus standard
Governments can help create a tolerant environment where innovation is accepted, including offering incentives.
Dr Feist believes that distributing information on improving efficiency in new construction and in refurbishment of existing buildings is an important role for governments. The issues it tackles are directly related to burning issues facing many countries today.
Here are some examples of countries embracing and encouraging this construction standard:
- As of mid 2016, eleven states in the US were offering incentives for developers of affordable housing to meet passive house standards. A major push here is a result of their carbon reduction goals.
- 2 councils in Ireland have now made passive housing standards the minimum building code, and the UK are building many of their new schools to passive house standard.
- In Italy, energy efficient builders are rewarded by being allowed to build on a bigger part of the land.
- In Vancouver, Canada, their policies are intended to remove barriers to achieving their carbon neutral goals. This includes encouraging Passivhaus construction and education of those involved in the building and permitting process. In mid 2016 there were about 240 passive house dwellings in the city.
The on-going challenge is to change habits within the construction industry
Dr Feist remarks that adoption of the Passivhaus standard continues apace because it’s not hard to do, he states, ”they (the construction industry) can learn how to do it but they have to decide that they want to learn”. In other words, we have to be willing to learn to design and build in a different way. Of course, both the consumer and the government also play a big role in this. The government to drive change to improve the quality of our living environments and the consumer in their demands (to which the industry services). The proof is there, the science is accurate, the issue is perhaps our mindset.
Passivhaus in New Zealand
Here in New Zealand the Passivhaus principles are gathering momentum. The New Zealand Passive House Institute (PHINZ) works to educate the building industry and energy efficiency the Passivhaus way and promote energy efficiency in order to benefit the community by improving public health and well-being and relieving fuel poverty.
eHaus, a New Zealand owned and operated business are currently leading the market offering a national team of specialised designers and trained Passivhaus tradespeople building throughout New Zealand. Chatterton Builders Ltd is the Canterbury Licensee (eHaus Canterbury), trained and experienced in Passivhaus construction, and a passionate advocate for healthy comfortable high performing homes.