Is R30 enough for an attic?

R30 is generally not considered enough for an attic by modern energy codes and efficiency standards, although it was acceptable in older codes for hot southern climates. Currently, the International Energy Conservation Code and Department of Energy recommend R-38 as the absolute minimum for attics in the hottest zones like southern Texas and Florida, and R-49 to R-60 for most of the country, with R-60 recommended for northern zones. An attic with only R30 will allow significantly more heat loss in winter and heat gain in summer than a properly insulated attic, leading to higher energy bills, less comfort, more draftiness, and increased risk of ice dams in cold climates because warm air escapes and melts snow on the roof. If your attic currently has R30 and you live in a mild climate and have already air sealed and sealed ducts, it may be adequate for a short term, but topping up to R-49 typically costs only a few hundred dollars in blown insulation and pays back within 2 to 5 years through energy savings. R30 is better than nothing, but it is below what most utility rebate programs and Energy Star require today.