Adding insulation (Edit: or radiant barrier)

[mlkgls]

This question may be more appropriate for the home and garden board, but has anyone added additional attic insulation and seen actual energy cost savings?

I’ve been trying to find a legitimate company to perform an energy audit, but no luck so far. My house is 30 years old and summer temps routinely top 100°-110° and the last few winters have seen temps in the single digits. HVAC system is fairly new and well maintained, but I’m sure our ginormous windows everywhere are not helping. I fell in love with the natural light when househunting, but brand new windows are not in the current budget. Additional insulation is more budget friendly, but I wonder how effective it would be.

[quesyrah]

Yes!

Our house was built in 1952 and had no insulation. We also have all original windows.

Window replacement is way outside of what we can afford for myriad reasons.

We decided to add insulation and it really has helped. It cost about $2,000. Because our walls are lath and plaster we opted to just do the attic.

[tacokick]

My parents did and it made a huge difference. Two different houses.

[mlkgls]

quesyrah, tacokick, Do you happen to remember what type of insulation was added? Fiberglass, spray foam, other?

[tacokick]

May 4, 2024 18:04:15 GMT -5 mlkgls said:

quesyrah, tacokick, Do you happen to remember what type of insulation was added? Fiberglass, spray foam, other?

I’m 99% sure fiberglass. I know it wasn’t foam.

[Poppy]

My H did it and it has helped. He DIYed by renting the blower thingy. Fiberglass. You do want to try to do any attic work before you do it (eg we installed recessed lighting), because you really don't want to try to walk around on the insulation. I think the ROI is pretty high generally on attic insulation.

[quesyrah]

May 4, 2024 18:04:15 GMT -5 mlkgls said:

quesyrah, tacokick, Do you happen to remember what type of insulation was added? Fiberglass, spray foam, other?

Fiberglass

[sadlebred]

I used cellulose in a previous house shortly after I moved in. A friend blew it in while I fed bales to the machine. It was pretty easy and took us about 4/hours per house (his and mine). We didn't have 3500 sq ft homes, so those may take longer.

[ellipses84]

I haven’t done it but I have a good understanding of thermal conductivity in buildings due to my career. If the attic insulation is affordable I think it’s worth doing. Heat rises and conversely if your house gets hot in the summer it will help block the heat from the sun.

Are your windows double paned? Are they vinyl? If not, there will still be a lot of hot /cold coming through them. Metal frame single pane are the worst for thermal conductivity. There are some cheaper things you could do in the meantime, like seal all cracks, put thermal film out on the glass and get thermal curtains.

[quesyrah]

May 5, 2024 12:00:35 GMT -5 ellipses84 said:

I haven’t done it but I have a good understanding of thermal conductivity in buildings due to my career. If the attic insulation is affordable I think it’s worth doing. Heat rises and conversely if your house gets hot in the summer it will help block the heat from the sun.

Are your windows double paned? Are they vinyl? If not, there will still be a lot of hot /cold coming through them. Metal frame single pane are the worst for thermal conductivity. There are some cheaper things you could do in the meantime, like seal all cracks, put thermal film out on the glass and get thermal curtains.

We have single pane metal frame windows. We have done all of this in addition to adding insulation to our attic.

It really does make a difference! We have no central heat/AC and our house was so cold in winter and so hot in summer.

[mlkgls]

May 5, 2024 12:00:35 GMT -5 ellipses84 said:

I haven’t done it but I have a good understanding of thermal conductivity in buildings due to my career. If the attic insulation is affordable I think it’s worth doing. Heat rises and conversely if your house gets hot in the summer it will help block the heat from the sun.

Are your windows double paned? Are they vinyl? If not, there will still be a lot of hot /cold coming through them. Metal frame single pane are the worst for thermal conductivity. There are some cheaper things you could do in the meantime, like seal all cracks, put thermal film out on the glass and get thermal curtains.

Thanks for the additional suggestions! I had assumed double-paned because one in my son’s room has a foggy section, but I honestly have no idea. The previous owners installed what I think are solar screens on the non street-facing windows, but our living room windows are huge and mostly south-facing; it can get warm in the summer. 

I have blackout curtains in the bedrooms, but maybe thermal curtains would help. MH runs hot and winter is the only time we’re not fighting over the thermostat. 

[simpsongal]

You want to check the attic ventilation - if you have soffits that allow air to pass you may need to add baffling. Theyre basically channels that allow air to flow under the roof and through the ridge vent. Blown insulation a can block all that air flow. If you just have an attic fan on the roof or gable this may not be an issue.

[genet313]

What kind of professional did you all hire to help you figure out what kind of insulation or other solutions to do to your home?

[sadlebred]

May 7, 2024 16:35:32 GMT -5 genet313 said:

What kind of professional did you all hire to help you figure out what kind of insulation or other solutions to do to your home?

You can also check with your local power company. Some will do a free energy audit of your home. A home inspector may be able to help, too.

[wildrice]

Our local power company (which is a branch of Excelon, a huge company) did a home energy audit for us for $99 I think, though that was in 2020 so I'm sure it costs more now. It had been kind of unbearably hot upstairs during the days, so they recommended adding insulation and an attic fan. I don't recall the specific costs, but because it was through them there were actually some decent rebates from some program and it ended up costing us less than half what we would have otherwise paid out of pocket. So definitely see if something like that exists in your state/with your company!

I do think it's made a big difference. It still gets hot upstairs, but not to the degree that it did before. I don't know how to compare costs since we only lived here a few months before doing this, but for comfort alone I think it was worth it. They did blow in fiberglass. Our previous insulation was maybe 1/4 of the thickness of what it is now - maybe even less.

Our energy audit actually said our windows were NOT the issue with energy loss! I thought that was interesting since they were in terrible shape and we've since replaced them anyway (some were barely functional). I don't think changing to new windows really changed anything in terms of energy cost or comfort, though.

[quesyrah]

May 7, 2024 16:35:32 GMT -5 genet313 said:

What kind of professional did you all hire to help you figure out what kind of insulation or other solutions to do to your home?

We didn’t hire anyone.

We knew our issues were no insulation and original single pane metal casing windows.

DH researched what kind of insulation to use and did it himself. He also just knew (from research probably?) that putting the window insulation film on the windows would help.

I think your local energy company will do a fee (or low cost) audit though.

[aprilsails]

We have large southwest facing windows across our living room and dining room. We installed Hunter Douglas honeycomb blinds across the back and the difference they make in terms of internal heat gain in the summer is incredible.

That being said, they are quite pricey.

Another long term suggestion is to plant a large canopy deciduous tree in the backyard in front of the large windows. In the winter and spring, when you will want the heat gain, the bare branches will let the solar gain in. In the summer and early fall, it will block some of the direct solar heating to the house. We've planted a sugar maple in the back since they grow like weeds here (Canada) and will provide both sap and sun blocking in the future.

[mlkgls]

We had our first estimate this week and surprisingly they said our insulation is okay, but that we would be better served by installing radiant barrier in the attic. People seem to love it or hate it around here, but I know next to nothing about it. It would also qualify for an energy tax credit.

simpsongal, good call. Our estimate includes replacing a non-functional attic fan and baffling in the soffits due to setting over time.

aprilsails, I don’t think I’ve ever seen those before, but that’s intriguing! Are they hard to clean?

My recent retention bonus is enough to cover the improvements/repairs, although the ROI is a little hard to calculate.

[dove]

We moved into a 1947 home a couple years ago. We did radiant barrier and new solar fans. Our electric bill literally cut in half. Our house feels so much more comfortable too. We live in TX where it gets so fucking hot, too

[aprilsails]

May 11, 2024 9:31:45 GMT -5 mlkgls said:

We had our first estimate this week and surprisingly they said our insulation is okay, but that we would be better served by installing radiant barrier in the attic. People seem to love it or hate it around here, but I know next to nothing about it. It would also qualify for an energy tax credit.

simpsongal, good call. Our estimate includes replacing a non-functional attic fan and baffling in the soffits due to setting over time.

aprilsails, I don’t think I’ve ever seen those before, but that’s intriguing! Are they hard to clean?

My recent retention bonus is enough to cover the improvements/repairs, although the ROI is a little hard to calculate.

We have white blinds and they clean so well it's shocking. I've had my kid splatter tomato sauce on the blinds behind the dining room table a couple of times and even if I don't notice for a week it comes right off with a wet cloth. They are a weird slightly plasticky material that is also reminiscent of fiberglass, but not fiberglass.