That depends…. Today everyone is all about green building but not everyone has the budget to go that route.
If I were building my 3,300+ square foot custom built dream home I would be more interested in saving money over the long haul in energy costs and would spend the money up front. For that scenario I recommend 1.5 to 2 inches of sprayed rigid foam insulation followed by blown in rock wool. There are two main reasons that I would go this route. First, the benefit of rigid foam is that it provides a higher R- value per inch than fiberglass or cellulose and it has the added benefit of sealing all air leaks. Of course all this comes with a higher price. The 1.5 inches of the foam seals the openings and then you can fill with the lower cost rock wool blown insulation blanket for a comprehensive energy saving solution. (more…)