The Green Home

Insulation options range from good, better, best

Posted December 23, 2011

‘Tis the season once again, readers – both for festive occasions and for rising heating bills in North Carolina. As temperatures drop across the area, homeowners across the area are battling with drafty rooms, cold upper floors, and gas bills that rise into the hundreds of dollars each month.

The average home in our area has over 2,000 ft of gaps, crack and voids that allow heated air to escape into the outside. When it comes to improving the value and comfort of your home, there is no safer bet than improving your home’s insulation.

Whether keeping your home cool in the summer or keeping it warm in the winter, proper insulation can help reduce utility costs by over 50% while eliminating drafts and cold spots that might be making various rooms uncomfortable. It’s the #1 most recommended item that arises from an Energy Audit, and homeowners commonly report a terrific return on a very modest investment.

With so many types of insulation now available, including fiberglass, cellulose, cotton batt, spray foam, and the recently introduced radiant barrier insulation, how does the average homeowner know which product and install method is right for them? Let me give you a quick breakdown of Good, Better, and Best options:


Replacing old, compressed or poor R-value insulation in your home is the baseline option you should take to improve your home. Current building code requires an R-value of 38 in ceilings, but the Department of Energy recommends R49. Walls vary from R-13 to R-19 according to the standards set in your geographical area. Your floors should be insulated to at least R19. Overall, these are all far higher than most older homes offer, particularly historic homes where insulation has shifted or compressed over the years.

Homeowners are most familiar with fiberglass insulation, which used to be the standard for new homes 20 years ago. However, time has shown fiberglass is prone to leakage and moisture issues, and is incredibly energy intensive to manufacture. Cellulose and cotton batt insulation is not only a sustainable option (made of 100% recycled materials), but also offers superior thermal performance compared to older materials.

For areas which are easily accessible (i.e. unfinished attics and rooms) you may opt to dense pack your walls between the studs, or for low-pitched roofs, you may opt to blow in insulation to build a thick blanket around the air spaces of your home. Blown insulation, in particular, is a quick, cost effective and easily installed option for unfinished attics which generally requires no extensive renovation or remodeling.


While cellulose and cotton batt insulation is definitely better than the older, decaying insulation (or worse yet, no insulation at all) the better option is spray foam insulation. Spray foam insulation is a truly exceptional product for homeowners, as it not only offers all the benefits of creating a thermal resistant barrier around your home, it also serves the added purpose of air sealing in the nooks and crannies where drafts develop. Additionally, it expands to fill hidden corners and hard-to-reach angles where cotton batt and cellulose insulation may not be an option.

Homeowners in semi-detached houses or near busy roads should note that spray foam insulation also provides excellent soundproofing, making for a warmer, more comfortable, and quieter home.


So far, the insulation options we’ve talked about are passive – they slow down thermal transfer to outside spaces by providing a cushion of temperature resistance – but there IS a more active option; radiant barriers.

Radiant barrier insulation is exactly what it sounds like; a barrier that radiates heat back into a home in the winter and radiates hot air out of the home in the winter. Think of it like a thermos for your house, protecting your home from unwanted elements.

Radiant barrier insulation is best used in conjunction with spray foam or cellulose and cotton batt insulation, giving your high utility bills a double whammy. Radiant barriers are the perfect upgrade to new or existing insulations and can be easily installed in a variety of locations, including the underside of roofs in attics, or over ceiling insulation.

A Final Word

While winter is the most common time for homeowners to show an interest in improving the home’s insulation, it’s important to remember that better insulation has year-round benefits, keeping warm air inside in the winter and keeping cool air inside during the summer. If either your heating or your cooling bills seem high, or if you’re generally tired of being uncomfortable in certain rooms of your home, improved insulation is a terrific first step to getting the comfortable home you love.


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About this Blog:

Bobby Ferrel, founder of Green Horizon oversees The Green Home blog. Ferrel is co-founder of Green Horizon, with offices in the Triangle and Charlotte, offering home owners and builders a one-stop shop for energy efficiency and green building. Services include home performance assessments, weatherization, closed crawl spaces, all types of insulation, HVAC and geothermal installation and maintenance. Reach Bobby directly at or visit him online at