Is Adding Attic Insulation Really Worth It? | Results from a Real House

I just got quoted $15k to insulate my attic with cellulose. Told the sales guy to take a hike. Small 1300sq ft house.

Brilliant, thank you. R-22-28’ish to R-48ish resulted in an almost 10% improvement in efficiency (reduced heat transfer). And youecexcel skills are impressive.

wow, you rock for putting in so much work into this video! thanks!

Thanks. Good video. Preparing to add insulation this weekend

Very cool! Thanks for doing this. You are a great example of why YouTube is great.

I think your water heater gas consumption is absolutely relevant. Presumably, making your house leak less heat would also cause your water heater need to heat less due to lower losses. And by all means, do a similar comparison for your cooling bill in the summer and then combine the two. I track my water use and energy use month by month, which is how I saw how dramatically we cut our water use ~2005 when we got rid of our top loading washer and got a front loader $400 off at a "scratch and dent" sale. Now I'm comparing our larger house in Kansas to the smaller house we had in California, and what my updates and improvements are doing to our energy use over time.

Great video! As you mentioned air sealing helps a lot in my experience. For crawlspaces too. Top plates and around vents.

I love this video because it shows realistic expectation from a realistic scenario. Most people aren't going to spend the time removing old insulation and air sealing. Thank you. I will say I'm hoping to have a little better efficiency as I did take the extra step to remove the old fiberglass batts, and air sealed a few big areas like light fixtures and bathroom vents and added approximately 15 inches of Greenfiber cellulose back. But again, this took a whole lot more time and effort which many people won't do, and I still feel I had several things I could have done better.

Great comparison, thank you!

Wow great data

I was looking for information like what you provided in your video. I have a 106 years old house in the badlands of Alberta, Canada. I think we would benefit with adding to our existing r30 cellulose capped insulation. Thank you for doing this video.

Did this project myself. Took along time to air seal. Cost about $2000, I built an insulated cat walk thru the attic. Saves us about 100gallons of heating the first year.

Awesome work ! thanks for sharing.. How much of an improvement in your comfort while in your home during the winters / summers ?

Very helpful, thanks.

Thank you for sharing you findings to the world. I’ve done the same added cellulose and added a perforated radiant barrier over the insulation. Curious to see if theres going to be a difference.

Hi Glenn, I’m in Fl and our home is about 18 yrs old. In our attic, I noticed that there is blown-in insulation mostly around the outer walls/perimeter of the attic with almost nothing on the inner floors of the attic (except around ductwork, there are piles around them.) Do you think I should add insulation? I’m looking to maximize energy efficiency for keeping our home cool! Thank you for the great video!

I have a bungalow just under 1300 sq feet, had 8" R-20 blown fiberglass in the attic. I added 10"-11" of cellulose to get the attic around R-50. I also dense packed cellulose around a couple knee walls inside a frame I built around them. What I did over a period of two years was compared all of my gas consumption. Looking at the previous winter, then compared to the winter after. This showed a 23% drop in natural gas consumption based on gigajoules of natural gas used for each billing period. Cellulose is definitely better than blown fiberglass, or batts. I've done all three in different homes, and the cellulose made the most noticeable difference.

I added 5" of celluose with vents to my 1060 sq ft house two years ago by a local contractor (Minnesota) for a total of $1,200.

Which one is better? Cellulose or fibre glass? I live in Canada. I was suggested to use fiberglass as my existing insulation is fiber glass. I am seeing in summer my seconf floor is getting hotter and AC is not able to cool second floor. But my main floor and basement is super cool. Not sure if attick cam help this

Can’t wait to see what I save…my insulation is 60 years old and flat with gaps all over the place…can’t decide if I wanna blow it in myself or just do rolls