Construction has remained largely the same for the last hundred years or so, with the exception of design and the occasional new technology or introduction of safer materials. In 1996, that changed with The Passive House Certification, which originally began in Germany under the name PassivHaus. It focuses on using the natural elements surrounding the house as well as thoughtful design and construction to make the building incredibly low-energy. As this certification is a concept of construction and not a brand name, the principles remain the same across the world while the implementation may vary. Passive Houses can have space heating and cooling energy savings of up to 90% of current typical buildings and over 75% compared to new buildings (Passive House Institute). That is close to zero-net energy use, especially considering heating and cooling a building is highly energy intensive.

Zero-Net Energy is a goal for many sustainable developers as it focuses on averaging the amount of energy a building uses over the course of a year to zero. What that usually looks like is an energy surplus in the sunny warmer months and an energy deficit in the cloudy colder months. Of course, that varies depending on location. PassiveHouse strives to reach net-zero energy through “superinsulating” the building to trap heat and energy inside as much as possible, while also orienting the building towards the sun to generate passive heat. They also focus on quality ventilation to ensure that the indoor air quality of the building is healthy and fresh.

Once the home is heated, it is important to keep the heat inside. To achieve this, houses are made super airtight, with mechanical ventilation to maintain fresh and healthy air quality. To keep the heat trapped, the house is superinsulated meaning it is insulated as much as possible, often exceeding normal insulation code. It is also often outfitted with Triple Pane windows to help prevent drafts and lessen heat loss around the windows.

In order to power mechanical energy and the high-tech ventilation system, solar panels are installed on the roof. These substantially lower the amount of energy received from the grid and generate surplus energy during the sunnier months to help the house achieve net-zero energy use. LED lights installed throughout the building help to lower the energy cost of lighting.

All of these measures contribute to the low to zero-energy costs of heating and cooling.

A great example of a Passive House in our local area is the Garfield House at Williams College. Built in 1850, you would never know this residential hall was any different. The Garfield House was renovated completely to include a variety of innovative construction details that help superinsulate the building. The Center for EcoTechnology helped with the process, acting as the PHIUS (Passive House Institute United States) Verifier, and inspected the building as well as advised the construction and design teams along the way.

Garfield House at Williams College

If you’re thinking of building your own PassiveHouse, or you’re looking to make an addition to your house as energy efficient as possible, we can help! CET can help you determine if Passive House certification is a realistic target for your project and then help you navigate the certification process from start to finish. CET offers a full menu of services to improve building performance, which you can find here. Contact us today to get started!