Frequently Asked Questions

Are Passive Homes new?

The Passive House is relatively new in the United States. However, with the goal of a carbon-neutral future, Europe residents have built more than 15,000 passive buildings in the last 10 years. Many have been extensively monitored by the Passiv Haus Institut in Darmstadt, to verify their performance. European government agencies have been adopting Passive House standards in their policy-making. (Read about the EU Commission’s move to implement the Passive House Standard.)


Can the passive house’s air-tight construction lead to moisture problems?

The Passive Home has a balanced ventilation system with heat recovery. This assures superior air-quality and comfort by continually exchanging the indoor air. Moisture is safely removed on an ongoing basis, along with other potentially unhealthy pollutants (for example off-gassing from carpets or furniture). People with allergies can easily control the indoor air-quality by specifying filters according to their particular medical needs.


Can you open the windows of a Passive Home?

Yes. You can open windows and doors in a Passive Home just like in any other house. Even if you are someone who insists on sleeping with open windows no matter how cold it is outside, studies have shown that cracking a window at night during winter has no significant effect on the performance of a passive house – it still works!


Does a Passive Home look weird?

No! Clarum can design and build a Passive Homes to your preferences and lifestyle. Passive Homes standards are an opportunity to be more energy efficient and limit our carbon footprint, but they are NOT a  limitation in regards to design and aesthetics.


Do I have to compromise on architectural design and the amount of windows?

With careful and early planning and design, Passive House standards can be integrated into a myriad of different architectural styles.  Selecting the correct windows plays a key role in achieving a bright, sunny passive home where you’ll never need to turn on a light during the daytime.


How is a passive home heated and cooled?

An underlying objective of a Passive House is to do away with conventional, inefficient heating and cooling systems. Due to the super insulation and air tightness, passive homes can be heated with less energy than your hair dryer uses. Then consider that your HRV (Heat Recovery Ventilator) is providing constant fresh air and recovering above 90% of your heat from your exhaust air into your incoming fresh air.  Cooling can also be achieved extremely efficiently.


What is thermal bridging?

No matter how well you insulate your home with traditional insulation measures, you’ll still be losing energy and comfort through your structural elements –this could be your framing, masonry or concrete. These structural materials have a very low resistance to heat transfer. While you consider insulating your wall cavities to an impressive R-26, your framing members have a resistance of roughly R-1 per inch meaning a typical 2×4 stud in the wall has a total value of R3.5. Accumulatively, there is a significant area of your structure that has  low thermal resistance. By adding additional exterior insulation you can effectively break these thermal bridges.


How does air tightness relate to comfort?

By designing and building a super air tight building envelope you can eliminate unwanted cold air from creeping into your house, causing drafts and hot and cold areas. Without air infiltration you have a consistent, cozy temperature throughout.


What is a passive home?

A Passive Home is an extremely comfortable, healthy, economical and sustainable home, designed and constructed to use up to 90% less energy than a traditional home.  This is achieved by enhanced insulation, greatly reduced thermal bridging, a virtually air tight building envelop, high performance windows and a heat recovery ventilation system.

Unlike “point accumulation” green building standards, Passive Home certification is based on actual performance results that require that the home uses less than 1.4kWh per square foot for annual heating demand and total annual source energy cannot exceed 11kWh per square foot. In addition the building shell must be airtight with less than 0.6 air changes per hour at 50 Pascal’s.

The result is a responsible and sustainable approach to home building.


Is passive house design the same as passive solar design?

No. Passive solar design is a climate and orientation specific design that is intended to collect, store and distribute heat in the winter and reject heat gains in the Summer. Passive House design, (while taking those elements into consideration), is a much more comprehensive design approach that focuses on every aspect of comfort, airtightness, and energy consumption.


Does the Clarum passive home use solar passive heating?

Considering that passive solar heating is the most cost effective means of heating your home, Clarum’s Passive Home designs incorporate passive solar design principles by carefully studying each home site and detailing orientation, fenestration and shading.


Interested in building your custom-designed passive house?
Get in touch with us:

Sean Misskelley, Director of Business Development
Tel 650.322.7069 x30