Without the right insulation R-values, hot and cold air alike can flow right through a home’s flooring, walls, ceilings, and attic. But what exactly is R-value, and what does it have to do with ...

That’s partly because 9 out of 10 homes in the U.S. are under-insulated, according to the Environmental Protection Agency (EPA), with older residences especially likely to need the extra care.

Picking the right commercial insulation depends on budget, building type, and climate. From spray foam to fiberglass batts, each choice has benefits for a particular use.