9 Steps to A Greener Code

Recent spikes in energy costs have increased the attention on regulatory measures that limit energy waste. Those same energy price increases have also gained the attention of President Obama, who made energy efficiency central to his stimulus package, specifying the need to improve energy efficiency in 2 million homes.

Last week we looked at air sealing, this week we look at insulating. In cold zones the level of insulation has increased, and so has the size of allowable cathedral ceilings.

STEP 2: MORE INSULATION, LESS CATHEDRAL CEILING (TABLE N1102.1 IRC AND IECC)

The code: In numerous areas of Chapter 11, insulation requirements have been increased or trade-offs that allowed for insulation reductions have been removed. This effectively improves the thermal envelope to retard heat flow. For example, floor insulation increased in two climate zones; basement insulation increased in several climate zones.

What it means to you:
In colder zones (5-8) there is a small but effective increase in insulation in walls, floors, and basements.

In addition to these modest increases, there was one significant change. Cathedral ceilings tend to have limited insulation and can account for large energy losses. The IRC has now limited the area of certain types of cathedral ceilings — those with reduced insulation levels — to either 20% of the entire ceiling area or 500 sq. ft., whichever is less. (There is no limitation on cathedral ceilings that are fully insulated.)

Basement insulation was also added to portions of Climate Zone 3 where, previously, you were not required to install it.

While some of these code changes occur only in the IECC and not in the IRC, it is important to note that either energy code can be used for those building single-family homes. Generally, the added costs of increased insulation material will be minor and the labor costs should not change, compared to the energy savings realized.

The 2009 building codes reflect practices that not only increase energy efficiency—air-sealing measures and increased insulation, for example—but also address sustainable building practices, such as moisture control.

Other segments of this series:

Part 1: Air Sealing
Part 2: Insulation
Part 3: Lighting
Part 4: Programmable Thermostats
Part 5: Insulating Mass Walls
Part 6: Efficient Windows
Part 7: Insulating Mechanical Pipes
Part 8: Exceeding the Energy Code
Part 9: Vapor Retarders