Passive House: The proactive choice

When it comes to incorporating sustainable design features into mainstream building design, the word "passive" would never be a word in my vocabulary. However, when to comes to Passive House, the word takes on a whole new meaning and is one of the most proactive steps one can take to design an environmentally responsible building. The Passive House, or Passivhaus in Europe, concept originated in Germany in the mid-1990's and the Passivhaus Standard was developed shortly thereafter. Although this is perhaps the most stringent design standard globally, the Passive House design allows a building to use significantly less energy, 75-90% less, for space heating and cooling. Through specific design and construction standards, a building can be transformed to require minimal energy consumption. Contrary to its name, this concept can be applied to residential buildings, office buildings, schools, markets, etc. To meet the Passive House standards, a building must comply with the following targets, found in the Passive House Planning Package: 1. Maximum 4.75 kBTU/(sf/yr) (15kWh/m2/yr) heating requirement. 2. Enclosure air tightness of 0.6 air changes per hour at 50 pascals pressure. 3. Maximum of 38 kBTU/(sf/yr) (120kWh/m2/yr) primary energy requirement. To achieve these goals, careful attention to the design and construction are of the utmost importance as all the building elements must work together to maximize gains and minimize losses. The key components include: building orientation to optimize solar and heat gains, superinsulation, elimination of thermal bridges, air-tight envelope, advanced window and door technology, energy recovery ventilation, and advances software modeling. Each one of these components will work together to achieve a staggering reduction in energy consumption. Although it seems like the energy reduction benefits would be enough to jump start a trend in the building market, and has been proven successful in Europe, Passive House has been slow to gain traction in the U.S. In part, the increase in the upfront costs is a deterring factor; however, when factoring in the lifetime energy savings the ROI is well worth the investment. The N.Y.C. market is alert to the benefits of Passive House design, as a building consulting engineering firm, we have seen an increase in interest from our clients and the local building community. The city's first Passive House was completed in Brooklyn in 2012 and now more projects are set to be developed utilizing the standard. Over the next few years, it should come as no surprise to see the Passive House concept entering the mainstream, joining other popular sustainable building certification like LEED and Net-Zero Energy Buildings. Zoe Reich is an environmental specialist at Edwards & Zuck, P.C., New York, N.Y.