Passive House vs. LEED

Over the years our team have explored various types of building certifications.   We have decided to focus on Passive House because we feel it is the standard for sustainable development.

LEED buildings are found to use 25-30% less energy than non-LEED buildings where Passive House reduces overall energy consumption by 60 to 70%.  In some cases where the majority of energy consumption is used for climate control the energy consumption can be reduced close to 90%.  LEED is a standard that focuses on five key areas: water efficiency, sustainable sites, materials and resources, indoor environmental quality, and energy and atmosphere where Passive House primarily focuses on energy consumption.  The variety of areas LEED focuses on has led to more lobbying from suppliers to become LEED certified and it is very limiting in s the types of materials that can be used regardless of effectiveness.  In addition, the cost sometimes is not worth the gain and although LEED has good intentions, the complex bureaucracy detracts from truly sustainable development when taking in account economic viability or value engineering.  Whereas, Passive House does require as many special certifications other than the windows and doors; much of the material and building characteristics are left up to the designer.

In our designs, even if we do not achieve the Passive House standard we use the tools and considerations in every design.  By properly positioning the building and using the Passive House thermal modelling software an intelligent design can be created that will seemingly last forever.  I will never forget visiting Chichen Itza, the large pre-Columbian city built by the Maya people of the Terminal Classic period (800 to 900 AD).  Even though these buildings were designed over 1000 years ago, humans had the technology to position the structures with consideration of the sun’s position.  This is apparent during solstice when a snake like shadow appears on the side of the main pyramid to indicate spring is coming.  For the past 1000 years this event has occurred because our planetary orbit doesn’t change.  In Saint John’s Newfoundland, where the weather is typically cold the majority of the year, buildings are commonly townhouses with common walls and small south facing windows.  When this city was first built, it was obvious that sunlight, and common walls that do not contribute to heat loss were essential to maintain a warm home.  As technology increased, designers could ignore these simple rules and overcome heat loss with the use of technology.  Unfortunately, this has led to inefficient building placements and infrastructure.

Our goal is to use intelligent planning for our structures that will perform regardless of technology.  By doing simple things like positioning high solar gain windows south, having overhangs to block the sun during the hot summer, and creating a well ventilated living space we can create building’s far more efficient than the majority that are built today without the need for expensive environmental control systems with limited life spans.  A building placed in a position where it has to continually battle mother nature will always be inefficient.  Our company is doing it’s best to bring “intelligence” back into design to create buildings that will perform effectively for generations to come.

David Peddle, P.Eng.

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