Interior of the RPA LivingHome 1, a new Passive House LivingHome designed by Richard Pedranti Architect (RPA).

Passive House is the leading building standard in many countries, and U.S. consumers are beginning to catch on. In light of Plant's own Passive House LivingHome launch, we wanted to share some background on what it means to build a Passive House and how it benefits you, the homebuyer.

The Passive House Standard

Passive House is both a building standard as well as a design methodology used to attain that standard. Though generally relayed in terms of energy efficiency, the intent of Passive House is occupant comfort—creating an ideal indoor environment that’s healthy and pleasant all year-round. No temperature swings, drafts, or hot spots; no condensation, mold, or mildew; no constant fiddling with a thermostat. The Passive House standard ensures outstanding thermal comfort, air quality, and sound insulation, with minimal effort from occupants.

The careful design and construction techniques required to meet these standards also achieves the building industry’s most advanced energy performance—Passive Houses generally use 80% less energy for heating and cooling than conventional buildings. It’s a true win-win.

More information can be found in this brief introduction to Passive House created by Plant Design Partner Richard Pedranti, one of the nation’s leading experts in Passive House design and construction.

Passive House versus other common building standards, courtesy of Richard Pedranti Architect (RPA).

Passive House Design

Here are Pedranti's time-tested principles and how he applied them to the RPA LivingHomes:

Optimal Solar Orientation
Passive House siting and design are informed by detailed solar and climate data to take advantage of the sun’s heat during the winter and avoid overheating in the summer. If you build a Passive House LivingHome with Plant, your design will be optimized to your specific lot.

High Insulation
Passive Houses are super insulated, using up to three times the insulation of a standard home to create a stable, comfortable environment with minimal use of heating or air conditioning. The insulation value required for your RPA LivingHome will be determined by your unique climate zone.

High-Performance Windows & Doors
To achieve required air tightness, insulation, and solar heat gain values, Passive Houses utilize high-performance windows and exterior doors. RPA LivingHomes are designed for Zola products, with the exact specification (e.g., double or triple pane) informed by your building location and design.

Airtight Enclosure
Passive Houses are designed, constructed, and tested to ensure a virtually airtight enclosure, which is essential for high building performance. Blower door testing is required for Passive House certification.

Balanced Ventilation
Penetration of the building envelope is limited to a specialized air exchange unit that provides a constant supply of filtered, fresh air, greatly reducing dust, pollen, and pollutants. RPA LivingHomes are designed to use a Minotair energy recovery ventilator (ERV) or heat recovery ventilator (HRV), as needed for your climate zone.

Renewable-Ready
Because Passive Homes are so efficient, they can easily achieve net zero energy (NZE) with the addition of a small photovoltaic system. All RPA LivingHomes are solar-ready for those who wish to pursue this option.

The RPA LivingHome 2 with roof-mounted solar.

Passive House Construction

RPA LivingHomes were designed for prefabrication with the Plant Building System, which employs meticulous factory processes and quality control measures to meet the Passive House standards:

Work is conducted in a monitored manufacturing setting using precise fabrication tools such as CAD/CAM.

Mechanical, electrical, and plumbing systems are tested for function before shipping.

Highly accurate manufacturing processes, continuous sealant around doors and windows, and interior and exterior vapor tape produce a tight building envelope, ensuring that the home achieves modeled thermal and energy performance.

Building components are produced and stored in an enclosed facility, reducing exposure to humidity and other environmental factors that cause moisture-related damage and mold growth.

Inspections are conducted by certified, third-party agents to verify compliance with state and specialty agencies (e.g., Passive House Institute US), as required.

Why Isn’t Everyone Building to Passive House Standards?

In some countries, like Belgium, everyone is. Unfortunately the U.S. has been slower to adopt the standard, possibly because it requires a bit more work upfront (e.g., studying site conditions, conducting energy modeling), and formal certification through Passive House Institute US or Passive House International requires several tests and inspections by a certified agent.

Passive House proponents agree that the performance and quality assurances provided by these procedures far outweigh the incremental time and expense. In fact, as of 2016 the German Passivhaus Institut reported some 60,000 certified Passive Homes (mostly in Europe). The standard has only recently begun to gain momentum in the U.S., where forward-thinking consumers look to the success of Passive House programs in Germany, Belgium, Scandinavian countries, Japan, and other early adopters.

If you’d like to build a Passive House, check out the RPA LivingHome 1, RPA LivingHome 2, and RPA LivingHome 3 for inspiration. We’d love to help you build your dream passive home!