A passive house is defined as a house that is able to use approximately 86% less energy for heating and 46% less energy for cooling than neighboring homes. Passive house design eliminates the need for extra heating and cooling by building airtight homes that do not let in outdoor air. Using extra exterior insulation and multi-pane windows, the initial cost of building a passive house is greater, but the energy savings over time are expected to return the investment.
Passive houses grew in popularity in the 1970’s, when energy costs peaked due to petroleum shortages around the world. Today, there are only 250 certified passive buildings in the United States, but interest has resurged. Homeowners are revisiting passive design to cope with rising energy costs, and to give themselves the option to live “off the grid,” outside of crowded metropolitan areas. Passive houses not only reduce energy costs, they reduce pollution generated by each home. Adding solar panels reduces traditional energy dependence even more and makes the homes more efficient.
In the past, passive houses were concentrated in the eco-conscious Pacific Northwest, but now passive houses are being built as far as Boise, ID. Brutally cold winters and unseasonably hot summers, led the Vonde family in Idaho to build a passive house in 2015. Since their move, the Vondes have seen monthly energy bills as much as $500 lower than neighboring traditionally heated and cooled homes. The homeowner explained, “we were attracted to the energy conservation, both for environmental reasons and to ensure lower energy bills in the future.”
Passive houses maintain their airtight construction by excluding fireplaces, stove vents, vented dryers, and other openings between the interior of the home and the outside. Many passive houses are also constructed with nontoxic, sustainably-sourced materials and take other eco-friendly measures. Passive house design also reduces the transmission of allergens like mold, mildew, and other irritants.
Housing starts and new home sales are expected to pick up in 2018, as sustained buyer demand continues to drive the need for newly constructed homes. Buyers needing to build anyway, may prefer passive design for potential environmental and economic benefits.