Home owners often treat insulation as an afterthought but it is arguably the most important building component for boosting efficiency and savings. Yet owners try to go cheap. After all, how sexy is insulation? Insulation isn’t cool like geo-thermal or solar systems. You’re just stuffing it inside the walls and between the joists where nobody sees it. Who cares? Just put anything in there so at least there’s something between the inside and outside, and save a buck while you’re at it, right?

The reality is that your choice of insulation is critical to the air flow and energy use of the entire house. It’s the difference between spending smart money INSIDE the walls versus wasting cash in utility bills from air leaching OUTSIDE the walls. No matter what air handling and conditioning systems you choose, their efficiency and peak function is directly affected by the type and manner of insulation you select. Go cheap and you’re undermining the benefit of your HVAC (which is the acronym for Heating, Ventilation and Air Conditioning if you wondered).

So what should you choose? Is there a one size fits all? Nope, depends on your climate zone, home characteristics, building code and other variables. So the first question isn’t “what?” but “who?” as in, who can help you make an informed choice?

Start by looking for technicians with designations, of which there are many, but I’ll mention three. The U.S. Department of Energy (DOE) endorses NATE, North American Technician Excellence , an independent certification body for HVAC/R techs that tests candidates in five speciality areas. The Environmental Protection Agency (EPA) offers Energy Star certification and guidelines for contractors and consumers. (That link includes multiple PDFs of best practices.) Finally, EarthCraft House is a green building program that includes Energy Star criteria and addresses all aspects of the building process from an environmental perspective. You’re looking for a certified professional, who could be employed in any of a few housing related disciplines (e.g. contractors, engineers, architects, inspectors), trained in air flow, energy and heating/cooling.

Some of the insulation materials include cellulose (dry and wet-spray), glass wool, rock wool, polystyrene, urethane foam, vermiculite and even earth or soil. Some are flame/moisture retardant and/or made from recycled material. The effectiveness of a certain type of insulation is measured by what you’ve likely heard referred to as its R-value, which is limited in what it indicates due to other factors like construction quality. Start by reading a general overview about home insulation at Wikipedia.

I’ll blog later about specific types and brands. For now, an example of one innovative product we’ve used successfully is Icynene, which is sprayed into walls, ceilings, floors and basements and expands in seconds 100 times its volume filling completely every crease and void. The soft foam hardens to form a continuous thermal barrier that eliminates air leakage, prevents moisture transfer (and therefore mold) and consequently blocks outside noise, dust, pollen and other allergens. It’s like a turtle shell and fosters energy savings up to 50 percent compared to traditional insulation used identically.

Bottom line, building science teaches that your house is a system. Each selection you make affects other things and the “effect” carries a consequence for your wallet. Do not discount your choice of insulation because pinching pennies is a recipe for being penny wise, pound foolish. Save a few bucks with cheap or unsuitable insulation and you’ll likely spend hundreds more a month in utility bills that would otherwise be substantially lower. In other words, don’t heat or air condition outside, the sun and wind do that naturally.