What is a Passive Certified Home?

The History of Passive Homes

The Passivhaus house concept originated in 1988 with a conversation between Professors Bo Adamson of Lund University, Sweden and Wolfgang Feist of the Institute for Housing and the Environment, Germany.

The first passive homes were constructed in 1990, a set of 4 row houses in Darmstadt, Germany. In September 1996 the Passivhaus-Institute was founded in Darmstadt to promote and control the standards. Since then, thousands of Passivhaus structures have been built. In the US, the number of passive-certified homes is growing, with certifications more than doubling in 2017 over the previous year.

Reduction of Energy Use

Passive homes are very well-insulated and virtually air-tight, which greatly minimizes the loss of heat. This means no furnace (you read that right) and extreme energy efficiency. This is primarily due to an incredibly tight and highly-insulated building envelope, solar-conscious design and a Heat Recovery Ventilation system.

All of the heating in a typical passive home can be met by a single 1000-watt heater. Heat from people, lights, appliances and the sun does the rest. And in the hotter months, the home stays delightfully cool without the need for air conditioning. Shading and well-planned window orientation helps to keep the house at a comfortable temperature.

Because passive homes are so airtight, they require an HRV system. Heat Recovery Ventilation systems cycle air throughout the home, pulling in fresh air, filtering and tempering it with the native air, and moving it throughout the house.

A Heat Recovery Ventilator provides a constant, balanced fresh air supply and helps maintain even air temperatures throughout the house. The resulting system not only saves up to 90% of space heating costs, but also provides healthy indoor air quality. Additionally, passive homes are extremely quiet. The passive home is a tranquil sanctuary with its nearly silent ventilation system (no blasts from vents), super-sealed joints, and maximized insulation.

Function Following Form

The design considerations and building science required to achieve passive-home standards can be integrated into any style of architecture and any type of aesthetic. The passive house standard is an opportunity rather than a limitation. It opens a multitude of doors to reshape our approach to construction in order to create homes that are friendlier for their occupants and the environment.

The Science of Passive

Unlike “point accumulation” green building standards, Passive home certification is based on actual performance results that requires homes to use less than 15kWh annually for space heating demand per square metre of usable living space. In addition, the building shell must be airtight with less than 0.6 air changes per hour at 50 pascals. To become a certified Passive Home, a home must meet very specific standards set by the non-profit organization, Passive House Institute United States (PHIUS).

At Clarum, we use the PHIUS+2015 model for our climate-specific and cost-optimized guideline for constructing passive homes in California. While it is not mandatory to work with a trained consultant when building a passive house, but in the long run, it’ll be quicker, easier, and less expensive than doing it on your own.

Find out more about Clarum’s passive home process, then give us a call at 650.322.7069 to get started with planning your custom dream home.