What is Passive House?
Passive House, Unsurpassed Comfort and Energy Efficiency
Passive House or Passivhaus is a results based method for planning and constructing buildings that provides an extremely comfortable and healthy indoor environment, while at the same time reducing the buildings’ primary and space heating energy needs by as much as 90% over stock homes. Most importantly, a Passive House doesn’t require the occupants to change the way they live. No restrictions on opening windows, no shutters to close or open and no complicated computer controls or mechanical systems. The Passive House method can be applied to almost any type of building, from homes and apartment buildings to schools and offices or even industrial buildings. The Passive House method can be applied to almost all construction techniques from standard stick frame (2×4 etc.) to concrete or rammed earth and even straw bale.
The key principles in Passive House are:
- Minimizing uncontrolled ventilation (air leakage), through walls, windows and doors, carefully controlling air exchange with a heat recovery ventilator and balancing relative humidity to maintain excellent indoor air quality and eliminate the possibility of condensation and mould growth
- Greatly reducing heat loss by providing good insulation, high performance windows and doors and minimising thermal bridges (areas of the structure that typically have poor R values)
- Careful consideration of the building orientation and window size and locations to taking advantage of free solar energy to let the sun help warm the home, but prevent overheating in the summer.
The name Passive House or Passivhaus can be misleading. It’s not the same as the passive solar houses that were popular in the 60’s and 70’s though passive solar gains do play a role in the design. Passive House is a German word and refers to a rigorous, voluntary standard for energy efficiency in a building. These buildings are considered ultra-low energy, using 80%-90% less energy than a conventional house for space heating and cooling. Passive House is the only internationally recognised, scientifically proven, performance-based energy standard in construction.
Passive House is a methodology, developed in Germany over more than 30 years by physicist Dr. Wolfgang Feist and Bo Adamson. It has been very well documented, verified with real world examples and scientifically proven with over 50,000 buildings constructed around the world so far with more added every year.
Passive House is a performance-based methodology, which is why it can be so effective yet flexible. Great care and attention is given to all aspects of the design and construction so we know it will perform as expected before it’s even built. Proprietary software is used to accurately verify the performance before any construction begins, which allows us to design each building for the specific site, orientation and client. There is no guess work or speculation and no performance gap.
Did you know that the Saskatchewan Conservation House built in 1977, is considered the precursor to Passive House, with a primary energy consumption of only 15% of what it would have used as a conventional house. Have a look at the Passivhaus fundamentals.
Passive House has really taken off over the last decade with over 50,000 units worldwide. Of the 2000 plus units in North America, Vancouver has some 600, the most in any city in North America!
A great short film on the Austria House at Whistler.
Here is a link to the Passivhaus Institute website with dozens of videos and literature.
Benefits of Passive House
The many benefits of Passivhaus construction over regular Canadian Building Code construction include:
- Superior indoor air quality and comfortable humidity levels, very low airborne particulates and low CO² levels because of properly calculated and controlled ventilation.
- The highest level of interior comfort of any building, with all surfaces at the same temperature (including the windows), never any drafts and no temperature swings.
- Extremely quiet – Triple-pane glass and thick insulation in the walls also provide superior sound insulation.
- Super energy efficiency – Performs 80-90% better than standard construction, with simply no need for a conventional heating systems.
- More durable – detailed and advanced design, better building components, proven building science.
- Very low maintenance and very simple mechanical systems.
- Resilient – the most resilient construction standard anywhere, which maintains livable conditions even during power outages, relies very little on any mechanical systems.
- Sustainable because of very low energy consumption and durable construction.
- Passive Houses can be built in any climate zone and applied to almost any construction type, utilizing a wide variety of readily available building materials and methods, from stick-frame to masonry or even straw-bale.
- Already over 50,000 units in more than 35 different countries.
While Passive House is certainly the world’s most ambitious and verified energy-efficient building standard, most people invest in this type of construction for the higher quality of living.
Net Zero, LEED and Passive House
Passive House is an obvious platform when planning for net zero construction. Net zero construction means that the building produces the same or more net energy than it consumes. It stands to reason that before we worry about producing excess energy, we need to first reduce the energy we consume. With only about 10% of the space heating requirements of conventional homes you can see that it makes sense to start with an energy efficient envelope before we take it to the next level and aim for Net Zero.
LEED stands for Leadership in Energy and Environmental Design, and in principle is a great idea. In my opinion though the principles are not cohesive. It is based on a point system whereby points are earned by utilising low embodied energy materials, or locally sourced components or low VOC adhesives and paints to name a few. This is all well and good, but it is possible to achieve LEED certification without addressing energy use or occupant comfort. Now imagine employing LEED principles to a Passive House. Low embodied energy, excellent occupant comfort, recyclable materials like metal roofing etc. and the best space heating energy performance standard in the world.
The 2012 British Columbia Building Code has a new provision that took affect in December of 2014. These changes require all new residential construction to meet minimum energy performance. The new standard really does little to address health or comfort, with only marginal thermal performance improvements. With a little more planning and care, you could bring your new home to Passive House standard with all the health, comfort and energy benefits.
By building to the Passive House standard, we can reduce our carbon footprint, reduce our dependancy on non-renewable energy sources and enjoy some of the most comfortable and healthy homes possible.
Please feel free to contact me to find out more about Passive House and how you can benefit from this method with your new home.