Not long ago I spoke with an insulation expert on my Saturday show. We spoke of the many different ways you can insulate your home to help save money on your home energy bills.

See, it’s not good enough to have the latest, greatest most efficient HVAC system in your house. It’s important, but in my opinion it’s not the most important.

The idea of home comfort is to heat and cool your inside air in the most efficient way, then hang onto that air for as long as possible before you need to start the process all over again, and to do that your insulation needs to be up to date. It does no good to spend money to heat and cool the air only to have it escape from your home due to air leaks and poor insulation in your walls and attic.

That’s why I believe insulation is the place to start saving money on your home’s energy bill.

Where do you start with the insulation? Let’s go to the attic.

Stick your head up into your attic and see if you can see the joists on the attic floor. You can? Then you don’t have enough attic insulation. You need 20” of blown-in insulation (fiberglass or cellulose) to be in the running for having enough attic insulation. Fiberglass insulation runs about 2.5R per inch so 20” will get you about 50R which is a great number.

“Excuse me Dave, I have a question”.

Go ahead caller.

“If 20” is a good number is 30” a better number?”

30” is certainly a bigger number and to some effect it is a better number. It is also a more expensive number. But insulation will reach a point of diminishing returns and once you reach 20” you are at a good spot.

“Follow-up question if you don’t mind?”

Please, go ahead.

“I had 20” in my attic when I had my house built 15 years ago and I haven’t taken any out, so I’m still ok, right?”

Probably not. Insulation will settle over time and compressed insulation is not a good insulation, so measure. 20” is the number you are looking for.

So, if you need more/new insulation you basically have 3 choices. I will give them to you from least expensive to most expensive, which also happens to be least effective to most effective.

• Blown-in Fiberglass or Cellulose.  Either works well.  Both are blown into your attic. DYI is ambitious but can be done, but not by one person.
• Part spray in foam, part blown-in insulation. This is solid. Company will do a fairly simple test on your house to find out where the air leaks are and close them with open-cell foam. Then will blow blown-in insulation into the attic. Your air leaks are sealed and you have the comfort of insulation.
• Spray in open-cell foam. Sprays into the rafters in your attic. This is top of the line and a great investment. Doesn’t settle so remains full strength as soon as it is sprayed in. Keeps cool in in the summer, and hot in in the winter. Not sure how it knows, but it does. Have this in my attic 15 years and can document lower energy bills.

Oh – speaking of lower energy bills, when you are shopping for new insulation don’t believe everything you read. Insulation companies love to tell you that “You will save up to 70% on your bills” or “Your attic will remain a constant 75 degrees year ‘round”.

Take that with a huge grain of salt. They have no real idea how much you will save as a lot goes into figuring that out – stuff like how low/high do you like to keep your thermostat set, what will the weather be outside, will it be a summer of 15 straight days of 100° weather, will there be a deep freeze this winter.

They don’t know so temper your expectations a little bit.

But I will tell you that proper insulation in your home will save you money from the moment it is installed.