Sealing the Envelope

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One of the areas of consideration when "going green" is evaluating and improving the building envelope.  These are the parts of the building that separate the interior space from the exterior.  This shell includes the foundation, exterior walls, windows, roof, exterior doors, and floors.  When you think about energy efficiency, this just makes sense.  When it is cold outside, we want to be warm.  When it is hot, we seek the cool interior.  Any transfer between the inside and the outside results in greater energy use for us to be comfortable. 

The two main action areas of closing the envelope are sealing and insulating - the main goal being to separate the inside and outside air.  If you are going for a specific certification, you need to be sure to solve these issue up to their code, but to seal a building you can use materials as simple as caulk and as advanced at OwenCornings new Energy Complete sealant. 

The roof and windows are two important considerations.  The options for roofs range from green roofs, which can be as simple (see left) or complex (see below) as you choose, to the installation of solar panels - a great way to create your own energy.  Green roofs also help prevent the heat island effect in urban areas - an extra plus!  Windows also have insulation and coating that helps let light into the building while reducing heat/cold exchange.  These low-e windows are increasingly common in all types of construction and are even part of many building codes.

Doors and the efficiency of the HVAC system  play a huge role in helping to seal the building envelope and keep the occupants comfortable and healthy.  One interesting consideration when sealing a building is managing CO2 content.  Again, there simple and complex solutions.  Opening the windows and allowing for a cross breeze refreshes the inside air.  There are also CO2 sensors that work with the HVAC system to take in outside air when a specified level of CO2 is detected.

When considering "going green" it is important to realize that there are many steps, considerations, and options - sealing the envelope is just one.  Determining your goals at the onset can help you focus your attention and resources in a way to achieve maximum results and help take another step toward sustainability.