Eartha Steward: New building code will help lower energy bills
November 14, 2012
Can you tell me about the building code upgrade that the towns and county are considering, from an energy perspective?
– Doug, Silverthorne
Let me tell you about the IECC (International Energy Conservation Code) 2012. The building departments are currently considering the 2012 Building Code set, of which the IECC 2012 is a part. All Summit County and town building departments are currently using the 2006 code sets. The building code applies to new construction and to remodels as well. If you build an addition to your house, the addition will need to be built to current code.
What does it mean for homeowners and renters? Generally speaking it means lower energy bills, tighter and safer homes. The Department of Energy recently released a study on the cost and energy savings of upgrading from the 2006 to the 2012 IECC. They found that homeowners will save $13,166 over the life of the home using a 30-year estimate that includes initial investment financed through increased mortgage costs and tax impacts. Energy bills will be approximately $620 lower than houses built to 2006 code. There is also an additional cost to building. A 2,400-square-foot house built on a slab will cost approximately $3,322 more to build.
What are the key differences? The air sealing and insulation checklist is more stringent. This is a welcome upgrade, as appropriate air sealing is the most cost effective way to save energy in a home. Every builder will need to come up with a strategy to reduce thermal bridging through studs. A test of the building envelope with a blower door is included. We like this too, as it is a great way to show clearly and numerically how well the house is sealed, with a very small cost associated with the test. Whole house mechanical ventilation is required, not in the energy code actually, but in the general building code. As houses are tighter, it makes sense to control the air that goes in and out. No longer will we be pulling air from nasty crawl spaces and moldy areas. Contractors can include a simple exhaust fan to accommodate this requirement and ensure adequate air quality, instead of more expensive systems like Heat Recovery Ventilation. The new Energy Star-certified Peak One homes in Frisco have chosen this affordable option.
As it is written, there are several ways builders can meet the code. They can chose a ‘simulated performance path,’ which is basically a Home Energy Rating that takes into account many aspects of construction, including insulation, air sealing, appliances and HVAC in one overall rating. Builders can follow a prescriptive path, where they fulfill individual requirements, but do not add up a total score. When approaching the building thermal envelope (insulation), builders can follow an alternative path for insulation, using an overall number to show adequate insulation.
There have been some concerns from builders that the new energy code will increase the cost of construction. This is true, but by about 1 percent, give or take, and the benefits to the homeowner are substantial. When reviewing the 2012 code set, we argue that the energy code is the only portion that actually saves homeowners money in the long run. We should keep this in mind when reviewing the specifics. And remember also, homes that can show lower energy costs sell for more money, especially if they are third-party certified to do so. Energy Star certification, for example, shows that homes are above code, or more efficient, by approximately 20 percent. These third party-certified homes sell for as much as 9 percent more, says a meta-study of over 1.6 million home sales in California.
Of the 23 counties surveyed by the Colorado Chapter of the IECC, 17 plan to adopt the 2012 building codes by the end of 2013. Summit County and town building departments will start to look at it this month. Often, contractors’ voices concerned with increasing costs can drown out the voices of community members who want homes built with current best practices and technologies. We look to our contractors to be experts in energy efficiency, but the reality is that a little push from the code helps the education process to happen. If you want to voice your support, send an email to your building department.