High Performance

Smarter, Better

What is a High Performance Building?

Any home exceeding the minimum building code requirements might be considered a high performance home. However, we feel a true high performance home should provide superior comfort to the occupants, save on energy costs, minimize carbon footprint and be essentially maintenance free. All of this at little to no additional cost to the occupants. To accomplish this the building industry needs to modernize almost every aspect of the conventionally constructed building. We at Simple Integrity think we are on the right track.


Residential construction methods have evolved slowly over the last century, but little substantial change has occurred. Residential building standards are dictated by a minimum building code enforced by local officials. These code built houses have been "good enough" despite being poorly designed, drafty and high energy consumers. High performance buildings elevate your grandfather's house to modern, high performance standards. The automobile industry has come a long way over the last century and we think residential construction should too.


Both private and non-profit organizations have developed various standards for high performance buildings. The most common of these are listed below:


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Certified Passive House - Arguably the world's highest performance building standard. These homes are up to 90% more efficient than a code built house. Each house requires computer energy modeling of the building using local climate data and must pass a rigorous certification process. PHIUS has strict requirements for insulation, thermal bridge free framing and air infiltration rates. No details are overlooked. Included in the guidelines are criteria for windows, HVAC, lighting, appliances and exterior water management. A Passive House is the pinnacle of  modern high performance building.

Certified Passive Houses are automatically certified as DOE Zero Energy Ready and Energy Star.



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DOE Zero Energy Ready - A mid-level high performance home meeting the criteria established by the Department of Energy. Includes many of the same criteria as a Certified Passive House, but is less rigorous with lower standards.



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Energy Star- A scaled down version of the Passive House standard and DOE Zero Energy Ready. 15-30% more efficient than a code built house. Includes requirements for insulation, air infiltration, windows, exterior water management, HVAC, etc.



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LEED- A more common standard for commercial buildings. This standard has a heavy focus on the materials used in the project and community planning, but has minimal impact on energy efficiency.




Facets of High Performance Buildings

High performance houses are constructed in a variety of ways to provide a thermal bridge free envelope, continuous insulation, airtight enclosure, balanced ventilation and durability. 


Thermal Bridge Free Envelope. 

Thermal bridging occurs when a poorly insulating material, like wood framing members, touches both interior conditioned and exterior unconditioned spaces. The thermal bridges common to conventional construction methods can lower the effective insulation by 30% but ,can be eliminated in high performance buildings. 


Commonly, high performance walls are constructed in one of two ways; as a double row of studs, 12 inches apart, providing an insulation cavity between or a conventional type stud wall wrapped in a continuous exterior layer of insulation over the wall framing. 


Continuous Adequate Insulation. 

A thermal bridge free envelope is a result of the wall construction and implies a continuous layer of insulation. Both double stud walls and exterior insulation create a thick wall that is aesthetically pleasing and provides ample room for thick, high R-value, insulation.


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Airtight Building Enclosure. 

Air infiltration creates uncomfortable drafty buildings that are expensive and difficult to heat and cool. In addition, unwanted air movement through walls carries moisture into the building that can lead to mold, rot and eventually  building failure. Mold issues caused by air infiltration can cause serious health concerns for the occupants. High performance homes strive to minimize air infiltration to provide the most comfortable, safe environment and save on energy costs.

Air infiltration is measured in air changes per hour (ACH50). A conventional house built in 1990 may test at 7 ACH50.  In 2016, New York State adopted a new energy code requiring new construction to have 3 ACH50 or lower. Remember, this is a minimum standard. We feel a high performance home should target 0.6 ACH50. 

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High Performance Windows. 

Windows are an essential, but are a particularly inefficient part of any building assembly. Traditional double hung, double pane windows have been the standard. However, they tend to leak, rot and need lots of maintenance. Most high-performance buildings use European style, tilt and turn, triple pane windows. These windows offer superior energy savings by using various insulating gases between panes and low-e coatings on the glass. A conventional window might have an insulating U-value of 0.30 while a window in a high-performance home might have an exponentially better insulating U-value of 0.13 or lower. 


Of course, the windows in a high performance home are meticulously air-sealed, over insulated  on the exterior with ridged foam and flashed to ensure no water damage around the vulnerable sills. 


Management of Solar Gains. 

High performance buildings are oriented to optimize the effects of the sun. The windows in a high performance building are often placed where windows are needed in the interior space rather than trying to optimize solar gains. This is because during the winter, solar gains can be helpful by reducing the heating demand. In the summer, they can cause discomfort through over heating of the interior space. Shading devices over windows and lo-e glass coatings are both helpful in blocking high angle summer sun while allowing low angle winter sun to enter. 


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Heat Recovery Ventilation (HRV). 

With the high degree of air-sealing achieved in high performance building,  mechanical ventilation is necessary to provide clean and safe air for the occupants. The cost of mechanical ventilation with heat recovery is very small compared to the cost of energy lost through the walls in a conventional leaky house. Heat recovery ventilation works by mechanically exchanging the stale indoor air with fresh outdoor air. An HRV uses an exchanger core to capture the energy in the exhaust air and return the heat to the home. Efficiency rates for heat recovery can exceed 90%. The indoor air quality is dramatically improved by the filtered incoming air and which benefits the occupants, especially those with allergies. 


Source Conditioning. 

Source conditioning is the act of heating or cooling the interior conditioned space. High performance houses are designed to have thermal bridge free envelopes with continuous thick insulation, high degree of air-sealing and triple pane windows. All of these improvements in the envelope lead to an interior space that is very comfortable and takes very little energy to maintain the interior temperature.  The cost savings in high performance homes is realized by reducing the size and cost of the source conditioning equipment. To put it simply, the required system will be small, energy-efficient and cost-effective to operate.

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Durability.  

Dry buildings last longer and are healthier. Poor water management is the largest cause of building failure. Water infiltrates in two forms: bulk water and vapor. Bulk water is mostly managed by the siding and roofing. Vapor most commonly attacks by way of a concept called vapor drive. Water vapor is able to move through many air tight materials. When the vapor laden air hits a cooler surface and condenses and the surface is unable to dry, it may lead to mold and rot. High performance homes approach this problem with an integrated rain screen. A rain screen is an added space behind the siding and roofing to allow water vapor and bulk water to dry via natural airflow. 


Resilience. 

Resilience refers to the ability of the building to resist extreme weather conditions. High performance houses tend to maintain preferred interior conditions through extended power outages due to increased insulation, better air sealing and better windows. 

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