Zehnder: Lubberland’s Edge Test Home


When Norbert and Robin were designing their retirement dream home in southeastern New Hampshire, they were inspired by the concept of dynamic energy efficiency. Living in a net-zero home that generates as much energy as it consumes would make planning for rising energy costs on a fixed income much simpler. This 1,900-square-foot test house for innovative Zehnder America was completed last winter. Norbert and Robin have since enjoyed exceptional comfort and indoor air quality in their modern, light-filled home, named Lubberland’s Edge.

“It’s a really special home that integrates numerous innovative technologies,” explains Norbert.  “There isn’t another project with an equal combination of features in our area.”

Four energy-efficient Zehnder systems are used to ensure comfort throughout the year while promoting indoor air quality:

  • The ComfoFond L eco geothermal system uses ground temperatures to preheat the incoming air throughout the winter and pre-cool it during the summer.
  • When summer temperatures become too high, the control unit turns on the Zehnder ComfoCool, a heat pump cooling system.
  • Bathrooms feature electric Zehnder towel-warmer radiators.
  • A Zehnder ComfoAir 550 Energy Recovery Ventilator (ERV) provides exceptional home ventilation, bringing in a constant supply of fresh, filtered air while removing indoor air pollutants, excess moisture, and odors.  

The ERV recycles heat in the winter and helps minimize the need for air-conditioning in the summer. The whole-house ventilation system supplies air to the bedrooms, living room, pantry, and office. Stale air is removed from the bathrooms, kitchen, and mudroom. The Zehnder geothermal heat exchanger was specifically designed to work with the ComfoAir 550 system for a seamless integration. Although there is a wood-burning stove in the living room, the couple has only used it a handful of times—for ambiance—throughout their first winter in the home.

“The level of indoor comfort and air quality is mind-boggling,” says Norbert. “It doesn’t matter what is going on outside, the indoor climate is always ideal.”

The kitchen exhaust hood works with the ERV system to ensure that cooking fumes are quickly removed at the source to promote indoor air quality. Particles from cooking are a common source of indoor air pollution and can be problematic in virtually airtight houses without adequate home ventilation.

Also, there are numerous, additional energy-efficient features in their home, including a heat pump water heater, LED lights, a ventless clothes dryer with a heat pump, and an induction range. A polished concrete floor on the first level provides thermal mass, helping to maintain even indoor temperatures. Triple-pane windows and doors and generous amounts of insulation reduce the heating and cooling load.

Lubberland’s Edge has a solar orientation to take advantage of winter sunlight, which gradually provides heat throughout the day. Even on overcast winter days, light fills the home. A vaulted ceiling in the living room, 11-foot ceilings on the first and second floor, and exceptional wilderness views give the space an expansive, open feel.

The home was designed by Kaplan Thompson Architects and built by FUTURO Construction to the Passive House standard, a rigorous certification for homes that use 90% less energy for heating and cooling than a code-built home. Drawing on both innovative new technologies and a passive solar design, the home generates as much energy as it consumes the home covers all of its energy needs with the 7.5-kW roof-mounted solar system. This is impressive considering this includes space heating and cooling, cooking, laundry, and hot water heating.

Norbert and Robin have found the house extremely comfortable while using very little energy.  Their new house fits with their financial goals and also protects the environment.

Morning at Lubberland’s Edge often involves live entertainment. The south-facing deck overlooks a pond fed by Lubberland Creek. Ospreys, blue herons, Canada geese, beaver, and turkey vultures put on a show as Norbert and Robin sip their morning coffee.