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Creating an energy efficient home involves a lot of variables which include:
- Appliances and electronics
- Doors and windows
- Utility systems like your air conditioner or water heater
But what about the home itself? Most homeowners tend to focus on low hanging fruit improvements to reduce their utility bills, and rightfully so. But there is another, much more impactful way to make a home energy efficient. Unfortunately, we often overlook it, because we can’t see it.
Insulation is a critical component in ensuring you have a truly energy efficient house. Though not as neat to look at as that shiny new flat screen or as fun to dig through as that fashionably sweet fridge it does a lot more to save you money those two combine.
How Insulation Works
Simply put, it reduces the transfer of heat through the walls of your home. By creating a barrier within walls, ceilings, and sometimes floors, insulation helps keeps your home warmer in winter and cooler in summer.
The energy savings become clear. If your home retains more heat in the colder part of the calendar, your heater works less. Conversely, if cold air is sticking around longer inside your home, your a/c won’t struggle to maintain a comfortable summertime temp.
If you want to test the full measure of the effectiveness of insulation, spend an hour sitting in your house with the a/c turned off in the middle of summer. It will get warm, but it will do so slowly. You could tolerate a very well insulated home for several hours before having to kick the air back on.
Now spend that same hour in your attic, outside of the protective shell of insulation and see how long you last (we honestly do not recommend you do this but trust us, it gets really hot, really fast). See, insulation is awesome.
You could also do the same test in winter, but really, we made the point, and nobody wants to catch a cold.
Insulation as an Upgrade
Before we get into the specifics of insulation, now’s is a good time to understand when your home may be in need of an insulation upgrade.
Generally speaking, new homes will have adequate amounts of insulation where necessary, in the walls and attic spaces. The quality of the materials used will depend on the builder, so it’s important to ask those questions, more so if the builder touts the new home as energy efficient. As we said earlier, it’s not just about appliances.
Now if you’ve owned your home for several years and your energy bills are creeping upwards, now might be the time to consider an insulation redo. That also holds true if your home is older than 25 years, and trying to reduce a commonly high bill is often a monthly struggle.
In addition to checking the common culprits of the HVAC system and windows and doors, insulation should be near the top of your regular inspection list.
In optimal conditions, insulation, particularly if constructed with fiberglass, cellulose or foamboard will last a generation. However, no home has ever spent its lifespan in optimal conditions.
Water penetration from the roof or walls will deteriorate insulation faster than most other external forces. If your home has had past leaks, it’s important to know if the insulation suffered any damage.
Homes in warm, coastal areas are at particular risk due to the more extreme climate and moisture and should receive more regular checks to stay on top of potential issues. Also, if it is left untreated, mold formation can break down insulation.
Since the goal is to minimize airflow, if your insulation has moved (by repairs in the attic or walls) or been punctured, you are reducing the barrier from its optimal levels. In attic spaces, loose-fill insulation is common and easily disturbed if the area doubles as storage or again, you have home systems that have seen some attention in the past.
Sometimes the fix is as straightforward as just filling in a few bare spots. For much older homes, 40 to 50 or more years, it could be more involved. The focus wasn’t on energy efficiency when these homes were built and most received inadequate amounts of insulation when compared with homes today.
Regardless of your home type, or its age, it’s never a bad idea to have your insulation looked at to determine any problem areas.
Where to Insulate
As mentioned, you most commonly find insulation in your homes walls and the floor of your attic. A few other spots make sense too. In homes with a crawl space, an insulated floor is necessary. The same holds true if you have a portion of your home atop an unheated garage.
Interior floors that protrude beyond a perimeter wall, such as a bedroom that sits over an exposed patio area, will also need to be insulated. In a heated basement, the walls will need insulation much the same as those above ground.
And window and doors will require some form of insulation including strong seals and weatherproofing. Basically, you are looking at areas of your home where air can escape allowing that heat transfer to occur.
Understanding the effectiveness of different insulation types isn’t exactly something you daydream about when thinking about home improvements. All the same, knowing what your house needs for effective insulation is just as critical as making sure the kitchen flooring matches the backsplash tiles.
Thankfully, to make determining your needs easier, insulation is rated based on its heat resistance by using what is called an R-Value. The bigger the R-Value, the better the insulation is at managing the flow of warm air.
The R-Value comes from numerous factors both related to the insulation itself and outside elements. On its own, the value originates from the density and thickness, as well as insulation type. As the insulation ages, its R-value decreases. The value will also decline in cases where it is damaged.
When figuring out what you’ll need in your home, it never hurts to consult an expert first, even if you choose to do the install yourself. Additionally, the US Department of Energy produces a handy guide that recommends the R-Value you should be using based on your location.
For example, if your home is in Houston, Texas, you’ll need attic insulation with an R-value between R30 and R60. In Chicago, Illinois, that initial value starts at R49.
Types of Insulation and Installation Methods
Insulation comes in numerous forms, with each designed for a different purpose or space. Here are the four most commonly used insulations in home construction today and how to install each.
Blanket Batts and Rolls
This form of home insulation is by far the most common. Large batts or rolls that typically consist of fiberglass fibers, this insulation is what you’ll find between wall studs, floor joists, or the rafters of your roof.
Available in other materials such as plastic or natural fibers, or sheep or mineral wool, this insulation is easy to install with a wide range of R-values. Depending on thickness, the fiberglass batts can be purchased in R-values from R11 up to R38.
How to Install
Unroll, cut to size, if necessary, and pack in between studs, joists, or trusses. If unsure of certain fit, consult an expert to determine the best method based on your home’s construction. 2×4 inch walls will handle a different thickness versus 2×6 inch walls.
Foamboard or Rigid Foam
Highly versatile, you can install foamboards almost anywhere your home needs insulation. Most commonly used on an exterior wall’s sheathing, you can also find it applied to the sheathing in interior basement walls.
Two times more effective at blocking heat than other types of insulation with similar thicknesses, foamboard is most often constructed with polyiso, polystyrene, or polyurethane.
How to Install
Much like paneling, foamboard can be installed directly to the sheathing or even brick or concrete, usually with a construction adhesive.
If you are looking to insulate the spaces in-between, loose-fill is your best bet. Typically available as a foam or fiber, loose-fill is formed from recycled materials like cellulose, fiberglass, or mineral wool.
This insulation stands apart from other forms due to its flexibility thanks in part to its “blown-in” method of application. It’s perfect for older homes or dwellings where additional insulation is necessary but pulling down walls is not.
How to Install
While loose-fill is excellent in ensuring minimal disruption to a confined space or area, a professional installer may be worth the extra cost to accomplish the proper thickness and R-values.
Spray Foam (also liquid foam or foam-in-place) is an attractive option to use when seeking to minimize the seepage of air, particularly in tight edges or crevices where traditional insulation may be ineffective.
Depending on the installation, some types can have very high R-values. The materials usually consist of cementitious, phenolic, polyiso or polyurethane.
How to Install
Spray foam, is, as the name suggests, a spray, which hardens after its applied. This insulation is available as either open-cell or closed-cell. Open-cell has less density than the closed-cell variety and sets with a sponge-like consistency. Closed-cell is denser and hardens with a thicker final texture.
Much like loose-fill, it may be a better option to use a professional installer to make sure of an accurate application.
There are a lot of ways to make your home energy efficient and put a dent in your monthly utility bill. Most are readily apparent. But it’s the ones you can’t see that may make the most difference.
If, even after you’ve tried all the common energy saving methods, you still feel money is slipping away in a less than efficient home, try to look inside the walls instead of between them. You may very well find a few extra dollars stuffed in there with your new or updated insulation.