Passive Houses

17 Feb. 2021

Passive house design principles

Credit: Passive House Institute

When the rate of climate change needed to slow down, human ingenuity stepped in. Environmentalists banded together to raise awareness, while engineers and scientists created amazing technologies like the electric car, truck, and bicycle. Indeed, the world was busy – and it still is – putting solar panels on the roofs of buildings, swapping out plastic water bottles for reusable ones, buying better bulbs for light fixtures, and reducing the amount of water that’s used on a daily basis. 

In 1988, Professor Bo Adamson of Lund University, Sweden and Dr. Wolfgang Feist of the Institute for Housing and the Environment decided to create a house that changed “the face of low energy developments and architecture and deliver[ed] enormous benefits to both people and the environment.” Three years later, they introduced the first Passive House building to the world in Darmstadt-Kranichstein, Germany. With its heating energy consumption 90% more efficient than a standard home at the time, Passive House buildings caught the attention of architects specializing in eco-friendly building designs.

What sets Passive House buildings apart from standard homes? Their ability to lower energy consumption significantly while providing a comfortable space for people to live in. Five principles guide the design of these buildings to ensure they are tightly sealed for no heat to pass through and out of them. The first way to accomplish this is through insulation. Passive House buildings must be extremely well insulated in order for them to retain heat. Eco-friendly materials like sheep’s wool and cellulose are used to provide at least double the insulation required for standard homes. The second principle is air-tight construction, where every possible place that heat can leak out of the building is taken care of. This is extremely important since Passive House buildings depend heavily on the heat generated by the people who live within the building and the appliances they use, rather than air conditioning and heating units.

The third principle involves eliminating any thermal bridges that can cause heat from the inside of the house to move outside. This often happens in the corners and studs of a building. The fourth is windows, orientation, and shading. Windows must be triple paned to keep heat in, and the house needs to face a direction that can take advantage of the sun’s light. Deciduous trees that are advantageously planted can provide the house shade in the summer so the house doesn’t overheat, and they can allow light (and thus heat) to enter when their leaves fall off during the fall and winter. The fifth principle addresses the air quality within the building. To ensure the air is healthy and not stagnant due to the building being airtight, a device known as a Heat Recovery Ventilator or an Energy Recovery Ventilator is used. Most times, a backup mechanical heating and cooling system is incorporated if temperatures become too hot or too cold, but these units are typically smaller and cost less than those for standard buildings.

 With at least 60,000 Passive House buildings in existence all over the world since 2016, their success stories have spurred all types of buildings to be constructed using Passive House design principles. The first Passive House building in the US was completed in 2003 by Katrin Klingenberg in Urbana, Illinois. Since then, numerous others have been built across the nation, with the Park Avenue Green being the largest residential building as of 2019. From supermarkets like the Tesco Eco-store in Ireland to public pools like the Bambados in Germany, the world is definitely mobilizing to slow the rate of climate change down. It is truly inspiring to see what amazing ideas come from human ingenuity.