Editor's note: This column will be published in the upcoming issue of Oklahoma Builder Magazine
By Steve Sullivan
Chair, State Associates Council
I was excited when I learned the focus of the current issue of Oklahoma Builder magazine was on green building, because we all know the greatest component of green building is energy efficiency and that is right up my alley with the work I do for Oklahoma Gas & Electric.
Let me share some of the things I think you should know when it comes to building energy efficient homes.
Why Build Energy Efficient Homes?
Steve Sullivan
When building an energy-efficient house, the whole house is treated as a system. It will perform better, be healthier, safer and it will use less energy.
Does this sound like a home you would want for you and your family?
Before starting any new construction, you should ask yourself if the home I'm building will be energy efficient. Making the right decisions up front is crucial.
State and local building codes set minimum requirements, energy-efficient programs offer a higher standard in energy efficiency, and they save energy, money and more.
These homes employ advanced materials and innovative designs. They increase energy efficiency, reduce utility costs while delivering a higher level of comfort in every season and provide a higher standard of construction value and overall quality.
Energy-efficient home energy benefits
There is a great inconsistency in the marketplace of what is considered an energy-efficient home. An energy-efficient home is built to more demanding specifications and is equipped with energy-saving features that deliver better performance, greater comfort, lower utility bills all while helping to protect the environment.
By design, these homes are more energy efficient than the standard new home.
There are no second chances to do it right the first time. It must be built right during construction. Energy- efficient homes are inspected by third-party home energy raters (HERS) during and after construction.
Thermal envelope
Energy-efficient building practices include tighter construction, including framing techniques and continuous air barriers that help to reduce leaks and drafts.
Four primary forces that affect the durability are building materials, air, heat and moisture.
The air barrier, thermal barrier and moisture barrier work together as a system to manage air flow, heat flow and moisture flow. It is important to control moisture, vent cooking and bathrooms with Energy-Star rated fans that vent to the outside of the house.
With energy-efficient homes, there are intensive caulking and foaming of all penetrations to stop air infiltration.
Improved thermal systems pay special attention to gaps, voids and insulation compressions so as not to reduce the effectiveness or insulating power of the insulation.
Typical homes have 70 percent natural air changes per hour while energy-efficient home have 35 percemt or less natural air changes per hour. They have insulation that is properly installed and increased insulation levels.
All of this is like closing a hole in your wall the size of an open window. You feel more comfortable, your house has less drafts and your utility bills are lower.
Heating Venting and Air Condition Systems (HVAC)
Energy efficient HVAC systems are more efficient, and their ducts are better sealed and are tested for leakage. HVAC systems are "right-sized," when it comes to tightly constructed energy efficient homes. Bigger is not better.
Duct connections must be sealed properly. Doing it right helps keep dust and other air quality hazards out of your house, improving indoor air quality. Energy efficient duct work has less than 5 percent duct leakage to the outside compared to 28-32 percent leakage in standard homes.
Windows
High-performance energy efficient windows will greatly impact a home's comfort as well as energy usage. Your windows must be sealed properly when installed or they will not perform as rated. Make sure your builder understands the science behind the window ratings.
Performance Testing
This is the most important step. Energy -fficient homes require performance testing including thermal bypass inspection, blower door testing for air infiltration and duct blaster testing for duct leakage. These test are performed by a licensed HERs rater who will assign the HERS index.
The HERS index was created by Residential Energy Services Network to give homeowners and buyers a standard by which they could measure the energy efficiency of houses they currently own or are planning to buy. It's kind of like the home industry's version of the miles-per-gallon rating you find in the auto industry.
A home's HERS Index Score is increasingly being used by builders to market their properties - the lower the number, the more energy efficient the home.
The U.S. Department of Energy has determined that a typical resale home scores 130 on the HERS Index while a standard new code-built home is awarded a rating of 100. As an energy expert, I consider HERS index of 70 or below to be energy efficient.
When you look at all the facts, the answer to the question of why build an energy efficient home is simple, it's because it's the smart thing to do!
