Bundle Up with Insulation
You wouldn’t let your child outside on a chilly day without a jacket. Think of your house like a kid that needs to be bundled up.
Insulation is about more than cutting down on that drafty feeling. It can easily reduce energy bills by 15%-20%. Proper insulation also raises your property value.
At the level of the big picture, proper home insulation is one of the most important things you can do for a massive and immediate reduction in greenhouse gas emissions. In the US alone, building insulation accounts for a whopping reduction of 780 million tons of CO2 emissions.
Like anything else, insulation comes in all shapes, sizes, composition… you name it. Making the right choice can be confusing. Focus on the material’s R-value. This tells you how effective it is at preventing heat loss.
Let’s say that the overall R value you want for your ceiling insulation, for instance, is 30 or more. This means that if the insulation you buy has an R-value rating of 6 per inch, you’ll need 5 inches of it to get to your overall goal of 30. Energy Star has created a zone map of the United States to let you know the R value you should be aiming for based on where you live.
The location where you focus your insulation upgrades (say, attic versus underneath your floor) is also important -- insulation is not one-size fits all. So, let your provider know what you’re going to do with the insulation you get and they can be of help.
Let’s pause here to note that even with insulation that has a high R-value, and even if you have plenty of insulating layers, you still won’t achieve what you’re hoping for if it’s not properly installed. The fit of the insulation between ceiling rafters, for instance, has to be just right.
If your insulation panels are too short, for instance, all your concerns about R-value goes out the window -- or through the ceiling. Fit has to be close to exact. (You have close to the same problem, by the way, if you just cram it in.)
So, even though it’s “just insulation,” be thoughtful about it and take some time to be reasonably exact when laying it in so that you actually get the R-value you’re wanting -- and, assumed, you were paying for.
Insulation material
Now comes the fun part, if you love making choices among confusing options. You probably had no idea how much variety there is in insulation material -- from fiberglass to reused bluejeans to sheep’s wool and more.
There’s also enormous variation in cost. Not surprisingly, the least eco-friendly can often be the least expensive. Environmental costs of making hazardous stuff do not typically get factored into the price you pay; so, be prepared to do the right thing.
Fiberglass
Fiberglass has traditionally been used as the go-to material for insulation. However, fiberglass uses very little recycled material and requires a lot of energy to make.
It’s also hazardous. Its fibers can cause any number of health issues if handled or installed improperly.
Listed below are some more of the more eco-friendly alternatives.
Cellulose
Made of almost 85% recycled newspaper, cellulose is the definition of eco-friendly and conscientiousness. The newspaper is processed and coated with borate-based fire retardants which provide reinforcement (to be harmed by the chemical fire retardants, you would need to actually ingest them). These ensure safety and -- here’s your bonus feature -- simultaneously work as a natural insect repellent.
The R-value of cellulose insulation is around R 3.5 per inch, roughly the same as fiberglass.
Cellulose insulation costs roughly 25% less than fiberglass, but installation will likely be more expensive as it requires a specialized machine to blow it into place. You don’t lay in panels. But, on the flip side, loose-fill cellulose insulation seals more tightly than traditional fiberglass batts. This means that the actual achieved R-value might surpass that of fiberglass.
(Fun fact: many pre-packaged or prepared foods in the U.S. have cellulose in them as an additive. For instance, “parmesan” cheese sold in the US may actually contain up to 5% cellulose if you’re not watching. So, if you feel you have more natural insulation around your middle than you’d wish, you might consider cutting out the pre-packaged stuff!)
Cotton (denim -- yep, bluejeans)
Recycled material (usually denim) compromises upwards of 85% of this insulation. Boron-based flame retardants represent the remaining 15%.
Cotton insulation has an R-value of around R-3.4 per inch, but it can be pricey -- up to twice as much as fiberglass. Because cotton is non-toxic, however, it’s perfect for DIY installation with relatively few concerns for health or safety.
And, it comes in batts, rather than loose fill -- so, while material costs are higher, you’ll avoid a hefty installation fee.
Wool
Sheep do it. They live in all sorts of extreme climates, even including the inner portion of the Arctic Circle. They can manage because of the extremely effective (and obviously environmentally friendly) “insulation” they’re constantly growing to cover their bodies.
Sheep’s wool has an R-value of R-3 to R-4 per inch and is naturally fire-resistant. Wool’s unique properties also allow it to absorb moisture without becoming damp.
The cool thing is that when wool absorbs moisture, it actually generates heat and prevents condensation. While somewhat more expensive than other options, it has no toxins and is a great fit for DIY insulation.
Polyurethane spray foam
Polyurethane is a plastic derivative. But, because it has such a high R-value (R-6.5 per inch), it’s considered eco-friendly. So, the value lies in the tradeoff: less of it’s needed, and the foam seals well, but the world certainly doesn’t need more petroleum products.
For a greener option, there are some types of polyurethane that utilize soybean oil in conjunction with the petroleum.
Rigid polystyrene
This is also a plastic that the U.S. Department of Energy considers to be a green-er form of insulation due to its high R-values (R-3.8 -4.4 per inch). It’s delivered either as boards or a spray material.
Polystyrene also increases the structural integrity of your home, given its firmness. And, while a plastic is a plastic is a plastic, at least this kind of plastic insulation can be recycled and reused.
Aerogel
Aerogel represents one of the more interesting insulation materials out there. Invented in 1931 by Samuel Stephens Kistler, aerogel consists of 90% air. Scientists produce it by placing silica gel under high pressure and heat to remove all the liquid that’s present.
It’s currently one of the most expensive insulation options. However, Aerogel’s R-value of R-10.3 per inch makes it three times more effective than, say, fiberglass.
While unaffordable for most for now, it has grown exponentially popular since its creation. Some think it could represent the future of insulation technology.
Icynene
Icynene is a 2-in-1 air sealant and insulator. Made from castor oil, this foam insulation increases in volume by one hundred times upon spraying. Shoot a little out and you’ve filled a volume! But, Icynene’s sealing abilities are both its strength and weakness.
On the plus side, Icynene severely reduces draft (it never met a hole it didn’t want to fill) and outdoor noise. It also allows water vapor to escape and prevents mold growth.
What’s the down side? It almost does its job too well. Because it seals so tightly, air flow to your home can really almost stop. So, you will need to install an air-ventilation system to offset the tight seal it provides.
It costs almost three times as much as fiberglass insulation. But, with an R-value of R-3.6 per inch coupled with sealant properties, Icynene can reduce your home heating and cooling bill by 30% - 50%. Savings this big will pay off.
ThermaCork
Here’s where the trees come in. ThermaCork comes from outer bark. As a finished product, it has a negative carbon footprint (that is, it is doing more overall to reduce carbon in the atmosphere than it takes to make it) and it lasts much longer than other insulation choices. It also is completely toxin-free, hypoallergenic and great at reducing outside noise.
ThermaCork has an R-value of R-4 per inch (which is great) and has a property called thermal delay. This means that it delivers consistent temperatures even in climates with drastic fluctuations throughout the day.
Learn more ways to save on power with LADWP.
Learn more about the assumptions behind Magenta House water and power savings calculations.
DETAILS
Upgrade: Insulation for walls and ceiling
Goal: Make sure you have the insulation you need: replace,upgrade, install new.
Potential Savings*: You can save a lot (by doing just a little), depending on what you do.
Skill level: ★★★
SAVINGS*
Insulation has highly variable costs and savings structures as different climates, cities, and types of insulation come into play. But, no matter what, by addressing the matter of insulation at all, you’re going to be making a big difference to your energy savings, energy bill, and carbon footprint (under certain conditions, it could even be the largest contribution to carbon reduction that you can make).
