Building a home requires breaking and altering the laws of science. If we didn’t do this, our homes would be very cold in the winter and hot in the summer. We would not be able to control the humidity levels inside the home. The outside weather would control the inside conditions, verses the home controlling it. The second law of thermodynamics states that heat always moves from higher temperature regions to lower temperature regions, unless reversed by additional energy from an external force. Wall insulation disrupts this law by keeping the heat from leaving the home in the winter and keeping it outside in the summer. The law is also reversed when the air conditioner/furnace pushes cold air through the duct work into warmer rooms. This is just one of many examples of how a home interferes with the laws of science. Building Science is understanding how a property is going to react to the forces of nature.
The building industry has made vast advancements in technology over the past few decades. From the building science perspective, it can be looked at as good and bad. Constructing a home back in the day, before all this technology, forced builders to understand science in order to build a quality home that kept the occupants safe and comfortable. As technology advanced, the science aspect appeared to become less important. The thought was that technology would replace science. Sure, technology helps, but the laws of science always find a way. This can lead to major problems and cost a homeowner and or builder thousands and thousands of dollars. For example, using insulation in conjunction with a vapor retarder is a great way to keep unwanted vapor, as well as heat/cold, from entering a certain part of a home. The problem is that if the vapor retarder is used on the wrong side of the wall assembly (cold side), this can lead to condensation within the wall cavity. Continued condensation can lead to mold and deterioration of the materials. This can cause major damage to the building and health concerns to the occupants. If you use a vapor retarder, make sure it’s on the warm side of the wall assembly, so that the warm/moist air does not meet the cold air inside the wall cavity. (Keep in mind, this is a very basic description of this potential problem. Many factors can be involved. We recommend consulting with a building science expert familiar with proven practices using vapor retarders in your climate) This is just one example of how not understanding building science can lead to major problems. The key is understanding how to utilize this technology to allow science to work naturally, but in a controlled way.
As a builder, it is crucial to have at least a basic understanding of building science. We understand the industry has become extremely complex. There are so many new technologies and building code changes coming at you constantly. Successful builders have been able to surround themselves with the best subcontractors which enable them to concentrate on overseeing their projects and selling more jobs. Make sure you utilize the right company for the building science and energy efficiency side of your business. Energy efficiency has become a key decision factor for home buyers and will continue as energy prices rise. Make sure your firm is committed to building an energy efficient home so that you don’t loose a customer to a builder who is.
So how does a builder do this?
First you need to start utilizing an energy auditing company, such as GreenEdge, to assist you with designing the right systems to incorporate into your homes. Many builders in West Michigan are utilizing the HERS Index Rating (RESNET),to not only obtain the building permit, but to provide their customers with real numbers on the efficiency of their new home compared to other homes. You may also want to consider building ENERGY STAR Certified Homes, which will put you at the highest standard of energy efficiency and quality. If you are not already utilizing the HERS Index Rating, you are behind the curve. This rating is designed to do what the MPG rating does for cars. In regards to energy efficiency, it gives homeowners the ability to compare their home to others. It also allows the builder to show their customers their commitment to a quality home that will save them money.
Keys to the HERS Index Rating (RESNET)
- A detailed look at the thermal envelope, HVAC system, appliances and lighting. This information gets modeled into a program called REM/rate, which generates the HERS Index.
- There are two inspections of the home. One at pre-drywall stage and a final one after the home is completed.
- The HERS Index is used in many rebate programs, as well as labeling ENERGY STAR Certified Homes.
- Most building code inspectors allow this report to verify compliance with the Michigan Uniform Energy Code to obtain your initial permits.
- The reports will be given to you, which can be used as an energy efficiency information packet for your customer. These can also be used to sell future jobs.
***Law requires builders to follow the 2009 Michigan Uniform Energy Code. According to our sources in Lansing, the 2012 Michigan Uniform Energy Code is on the way. A blower door test will be required with this new code. A HERS Index Rating already incorporates this test. Utilizing the HERS Index will get you ready for this new code***