Insulate to save money


As a construction professional who did lots of research into energy efficient home design, I learned that insulation is the name of the game. On the first 30 homes we built, we installed separate electric meters on 5 or 10 different circuits to find out how much energy is consumed by different systems or appliances. We also designed active, passive, and hybrid solar homes, and experimented with all kinds of things in an effort to find out what’s worth doing and what’s not. The main thing we discovered is that insulation is the biggest factor in constructing an energy efficient home. Yes, you can gain 10% savings if the windows face south and the overhangs are correctly sized (and more if you live in an area of the country that has 300 days of sunshine and can get a solar water heater installed economically), but the most important factor is to limit conductive losses and air infiltration. This means insulating voids that are often overlooked during framing (corners, tees, headers, etc), and sealing the envelope and openings with tape, caulk, and foam.

For existing homes, super-insulating a water heater has the fastest payback of almost any DIY project (six months or less), but be sure to learn the technical details about this before doing so. Older water heaters are poorly insulated, so simply wrapping another layer of R-13 batt insulation around the unit is easy, fast, and pays off fast. With electric heaters, be sure not to restrict the pop off valve and leave access to the elements. With gas water heaters be sure not to restrict the air intake (research this on the internet).

Adding attic insulation can also have a rapid payback (because it settles over time), and some electric utilities offer special credits for doing so.

Attic access stairways or hatches are often a dead conductive heat loss area, so installing an insulating blanket over those areas can significantly improve the energy performance of a home. Leaving those areas uninsulated (which is common on most homes) is like leaving a window open into an otherwise tight structure.

Most people know about LED lighting and fluorescent lights, but many people don’t know that many older refrigerators can consume $30 in electricity per month.

If your utility company offers a free energy survey, request one, because it can be an eye opener, and some of the upgrades in insulation that they may recommend can dramatically lower your annual energy costs.


This is something that is often overlooked by home owners. It is good you brought it up. I own a home built 1978 - it leaks air like a crazy. It is also all electric! Our electric bills over the last few winters have been INSANE (some near $700).

We recently installed new triple pane windows in 90% of the house and put in a 96% efficient gas furnace and SEER 18 AC unit. Our highest heating bill this winter was around $80 bucks, highest electric bill was about $150 (which includes charging a Chevy Volt everyday). A bonus is we were able to keep the temperature at 68F instead of 64F. A huge savings, but I think it will take a many years to see the ROI due to the high cost of windows and HVAC systems.

Having the warmer house made it very obvious where we are losing a lot of efficiency. I can feel cold air pouring in around our door to the garage and our front door. We also have a cheap sliding door on the rear of the house that leaks tons of air. I’ve used some foam around the door seals, which helps, but I think really they just need to be replaced.

That’s a good point you bring up about attic access. I’ve been meaning to make some form of insulator over the stair entrance, but haven’t had much time to investigate it. Do you have something you’d recommend?

I also want to put more insulation in my attic. It’s original to the house (blown in) and has settled a lot. I’m not sure if I want to do more blown in or just buy the bats and roll them out. Much easier, but I don’t think it would be as effective.


Some building material supply companies sell insulated blankets to pull over access holes, but many homeowners create their own way of sealing them. Pull-down stairs usually protrude into the attic area. Our solution was to box around the protrusion with 2x10’s sheathed in foam insulation and use a hinged piece of 2" thick DOW foam sheathing to cover the entire box. The foam sheathing is lightweight and is rotated out of the way as one comes up the stairs into the attic (much like opening a horizontal door).

Yes, the blow-in insulation is more efficient than the batts (assuming that the R-value is the same) because the loose-fill products (fiberglass, rock wool, cellulose, etc) eliminate voids and seal more tightly around vertical framing components. It’s also usually cheaper if the work is hired out because less labor is involved in blowing insulation rather than hand placing and fitting batts. The amount of insulation will depend upon what area of the country you live in, but even in southern states builders now install attic insulation R-values between 30 and 38, or about 12 inches of fiberglass insulation.

On older homes with recessed lights (which can be another area of direct conductive loss), people may find that the cans cannot be insulated (due to potential heat buildup), so the solution is to stack batts around and over the cans while leaving enough air space between the cans and the insulation so that intense heat buildup cannot occur.


Yeah I was thinking about just building a box with the 2" foam that is only open on one side. When I need in the attic, I’d just lift it out of the way. Should be cheap and easy.


We had the luxury to build our own home and we sprayed 6" average in our attic. It made a world of difference for 2-story house and it is about as warm in the summer as the main level. Before, it was a 10 or 15 degree difference when you reached the top of the stairs.

We also did flash & bat on our walls & pleased with that as well.


Great points! I just added a ton of foam board and spray foam to the crawl space of my rental (the attic already has 14" of blown-in installed).

I’m also going to blow in another 8-10" on top of the insulation in my own attic, and I’ve already sealed and insulated the attic access (which was very drafty). Also in the plans are a new front door (also drafty) to keep more of our precious wood heat in!


So important!! Especially in the cold winters and hot summers of Chicago. I live in a 1912 building, to say it’s drafty (even with newer double pane windows) is an understatement. I’ve done what I can to insulate (sealed all cracks and use the plastic film) and switched out the fridge as soon as I moved in. Also, make sure to have a programmable thermostat to automatically set the temp while you are away from home. Another way to save on costs is through electricity. Do you know how much running your cable box/internet modems costs you each day? Me neither, but I do know it costs! :wink: I started unplugging both while away from home as well as when I sleep. I’ve seen a difference and perhaps you will too!!

I’m going to tag @gwen as she is a new investment property owner!! :slight_smile:


Thanks for the tag @MissMazuma! One of the things I’m going to do before it gets too hot is insulate the attic. It’s completely unfinished (to the point where I can see flashing through the slats), so I’m going to finish it off completely. Bonus is more living space! When are you coming over to help!?! :stuck_out_tongue:

#9 - here is the topic I was wanting to tag you on. Hope you find it useful!!

Side note - Welcome to the forum. Don’t forget to add your blog to your profile page (top right- click on profile) and introduce yourself with a new topic on the link below… :slight_smile:


Great tips - thanks. And you got me. We have an older fridge in the basement that I measured with one of those Kill-A-Watt thingies and it clocked in a $40 a month.

I need to man up and take it offline…


I’m also a construction professional. Do you own your own business or do you work for an organization?

I’m a Civil Engineer by degree, but I’ve been a construction project manager for most of my career in both residential and commercial buildings. Before I left the corporate world, about 4 years ago, I was a Sustainability Program Manager and Assistant Energy Engineer for a large High Performance Buildings Program. I also managed millions of dollars of building retrofits for Energy Savings Performance Contracts. It is funny how everyone wanted to jump right into installing renewable energy systems or high efficiency mechanical systems, because they were ‘sexy’ and it was easy to ‘show’, but I always had to stress that the small things like fixing the thermal leaks is the first step. We used to say "if it isn’t boring, it isn’t green’. :slight_smile:


I owned my own business for 35 years (general contractor), but now I’m semi-retired from that one. Still operate a rental management business, and still build a few commercial rental buildings. You’re so right–the boring stuff is where most of the savings are.


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