How to Keep Heating & Cooling Costs Down and Home Value Up
It’s no surprise that today’s homebuyers (especially those living in extreme environments like Fargo and Lakes Country) are looking for ways to increase both energy efficiency and the long-term value of their home, according to the National Association of Home Builders (NAHB). Whether you’re building new or renovating a home, there’s no better way than insulation technology to improve the comfort, efficiency and the health of your home
The best place to start is R-value, according to homebuilder Benjamin Custom Homes. Over the last several years, improvements in building sciences have allowed homes to be sealed tighter than ever before. As the industry learns more about energy transfer through materials, builders are using this knowledge to design better and more efficient wall systems that reduce heating and cooling costs. Generally, the higher the R value, the better.
BASIC: Standard Wall Assembly
In places like Fargo, most exterior walls are framed with 2×6 dimensional lumber and shelled with ½” OSB (oriented strand board) wall sheeting. Between the studs, R-21 batt fiberglass insulation and a layer of plastic sheeting are placed under the drywall.
Pros & Cons: Even though the insulation is R-21, energy leaks through the wood-on-wood connections, reducing the wall performance to R12-R14.
GOOD: Foam Insulation Wall Method
A standard upgrade for many homes is closed cell foam, which performs much better than fiberglass and adds tremendous strength, creating a continuous assembly leaving only the wood/wood connections uninsulated.
Pros & Cons: Superior between the studs, foam still performs substantially lower than the insulations R-value would indicate.
BETTER: Thermal Break Wall Method
A “thermal break” wall can use either use foam or fiberglass insulation and includes a layer of rigid exterior foam board that creates continuous insulation (CI) on the outside of the wall assembly, which largely eliminates heat loss through the studs.
Pros & Cons: CI can substantially increase the overall performance of the wall assembly regardless of the insulation used. The largest disadvantage of CI is the thickness of the wall changes as a result of the layering, so it creates dditional planning requirements for door jambs and windows.
BEST: In-Wall Thermal Break Method
This construction uses two different sizes of lumber. The plates are 2×6 and the studs are 2×4. The 2” difference in lumber thickness is filled with rigid foam board that gets pinched between the exterior sheeting and the 2×4 studs.
Pros & Cons: When coupled with spray foam it becomes an incredibly high-performing wall without increasing the thickness, However check with your local building codes since this method may require local approval.