Whether you are building a new home or remodeling an existing one, chances are you have considered building a green home. But what is a Green Home? By definition it is a home which uses less energy, water and natural resources, creates less waste and is healthier to live in compared to a standard home. Since each remodel is different, let’s talk about new home construction.
Most homebuyers get excited about selecting new appliances and kitchen cabinets but rarely give a thought about insulation materials which affect the cost of running their new home. The type of insulation material used greatly controls how much you will pay each month on your utility bill. Conventional building uses fiberglass batts in the walls and ceilings to control the conditioned living space. Walls are typically built with an R-13 value (resistance to heat flow) and ceilings with R-30. While it does work fairly well, if a gap is left in the wall space then the R-value of the insulation is greatly compromised. The gap allows air to move between the inside and outside of the home causing your HVAC unit to run and driving up your utility bills. Try holding your hand over a wall plug and see if you can feel any air coming out of it on a cold day. If you do then the R-value in that wall is very close to zero.
Blown in insulation in a new home is installed in walls using netting over the bare studs and blowing fiberglass insulating materials in behind the netting. While this eliminates the gaps left by batt insulation, my opinion on blow fill is that gravity still works. Eventually it will settle and leave a gap at the top of the wall. This type of insulation is best left to remodels of older homes without any insulation where it is not practical to expose the studs.
Spray foam insulation when properly installed is the best to use in controlling the living space. It is also the most expensive but does have great advantages. The spray foam fills the entire wall spaces leaving no gaps for air to penetrate. Smaller HVAC units can be used which helps offset the initial cost of the spray foam insulation. By eliminating air penetration you keep from having cold spots and allow your HVAC to better control the moisture level in the home. This in turn increases the longevity of your home and helps keep molds in check giving you a healthier living environment. The R-value of spray foam insulation can vary from 3.5 to 6.5 per inch of insulation depending on the type of foam used. This means that a 2x6 exterior wall can have a value of R-19 to R-35 while controlling air penetration.
