Passive House Design
Specific Climate, Siting and Sizing
Superinsulated Envelope


Passive House Standards


Specific Space Heat Demand

Pressurization test results (Infiltration)

Specific Primary Energy

Specific Cooling Energy


4.75  kBTU/sq. ft./year

0.6    ACH (@ 50 Pa)

38.0  kBTU/sq. ft./year

4.75  kBTU/sq. ft./year

To achieve certification and energy savings:

Strategic Design and Planning:

The Passive House Planning Package (PHPP) is the software that monitors the heart of how the intended design will perform.  It is an extremely detailed 30 page spreadsheet developed over the past 20 years via Passive House (PH) projects in Germany.  Once the design is entered, it is a wonderful tool for studying a variety of “what ifs” to value engineer the systems and components of your new project to meet the Passive House Certification.

Triple Pane Windows, German Windows,

Specific Climate, Siting and Sizing:

Critical to performance is the ability to understand the specific climatic data of your site and understand how this influences the design of the structures systems.  PHPP uses detailed annual weather data in modeling your structures performance.  Orientation of the windows can maximize or minimize solar gain and shading.  PH theory leans towards minimizing the surface area to interior volume ratio, favoring an efficient shape to minimize energy losses.

Air Tight Envelope

Super-Insulated Envelope:

“If you can keep the heating/cooling you produce in your home, you won’t have to keep replenishing it.”  This is the mantra of PH.  To keep the heating/cooling in, wall assemblies require greater insulation values to “stop the conditioned air” from leaving.  Walls are typically twice as thick as todays standard construction, for good reason.

Energy Recovery Ventilator

Advanced Windows and Doors:

The weak link of a home’s envelope are the doors and windows.  PH places significant emphasis on specifying high performance windows and doors to address this weak point in home design.  Most windows meeting the PH criteria contain triple insulated glazing, with non-conductive insulated fiberglass frames.  Multi-Lockable casements and well sealed french doors are the design preference.

“Thermal Bridge” Free Detailing:

Another huge weak point in standard US building envelope construction are “thermal bridges”.  These are gaps in our insulation layer usually caused by structural elements and utility penetrations to our exterior wall, allowing unconditioned air temperatures to “un-do”expensive interior conditioned air.  PH design attempts to eliminate thermal bridges via progressive mindful architectural detailing.

Air-Tight Envelope (But Diffusion Open):

Any one who has been in an older “drafty” home understands how stopping unconditioned air from squeezing to the inside, effects comfort and the efficiency of the mechanical system.  PH takes great care in designing, constructing and testing the envelope for a very minimal and controlled amount of air leakage to the interior.  Blower door testing is a main technique in assuring high performance.  Walls are virtually air tight, yet water vapors are allowed to dry out providing an excellent strategy in the prevention of mold.

Energy Recovery Ventilation:

The “lungs” of a Passive House come from a box called a heat (or energy) recovery ventilator (HRV/ERV).  It provides a constant supply of tempered, filtered fresh air 24/7 and saves money by “recycling” indoor energy.  The heat from outgoing stale air is “transfered” to the unconditioned incoming fresh air, while it is being filtered.  It provides excellent indoor air quality and consistent comfort, especially for people sensitive to material off-gassing, allergies and other air-borne irritants.


One of the best benefits to implementing PH design is the high performance shell.  This allows owners to save construction costs by eliminating expensive mechanical systems, including geo-thermal and radiant heat.  Passive solar gains, plus heat from occupants and appliances supply most of the needed heat. Supplemental heat is typically supplied by a 1000w electric heater (aka a “hair dryer”).  PH technique puts a project easier within reach for achieving true “Net Zero” performance (the building generates as much energy as it consumes over the course of a year), making use of solar energy system(s).

Thermal Bridge Free Design