In this guide we’ll cover everything you need to know before upgrading your insulation. To find out how much you can save by upgrading your insulation or see an estimate of how much it will cost based on where you live, check out our guide to saving money and energy by insulating your home.

How does home insulation work?

Insulating your home helps regulate the temperature: it prevents heat loss (during the winter) and heat gain (during the summer). 

Most of the heat loss in your home is from conduction, the flow of heat through solid materials. Think about the last time you touched the inside part of a window during winter: it was cold even though you were heating the air around it. That’s an example of conduction. 

Conduction makes the heat flow from the inside part of the window to the outside extremely fast, cooling the window and the area around it. 

Insulation limits this flow of heat. It traps the heat in the walls, floors, attic, or wherever you have insulation installed, slowing the rate at which it goes outside—and allowing you to save energy.

Insulation in your roof or attic also uses convection (the flow of heat through the movement of air) by stopping or limiting the chimney effect. 

The chimney effect is a phenomenon where, in cold weather, hot air rises and escapes out of your under-insulated or unsealed roof. As hot air leaks from the top, it leads to lower pressure within the home compared to outside. The pressure change means cold air is sucked in from the ground floor. So you’re constantly having to heat new air and losing the air you already heated. By insulating your roof and attic you can decrease or even eliminate this source of heat loss.

Types of insulation

The most common type of insulation is the type which protects against conduction. It basically works by trapping heat inside it so it can’t escape.

Here are the most common types of insulation, each of which performs a different role:

Roll insulation

• Insulation material: Glass fibers in wide, puffy sheets, with or without a paper or aluminum face
• Location: Best for long, unobstructed spaces like over attic joists
• Use: Stops heat loss into your attic and walls via conduction

Batt insulation

• Insulation material: Glass fibers in puffy strips, with or without a paper or aluminum face
• Location: Attics, walls, and between crawl space joists
• Use: Stops heat loss into your attic and walls via conduction

Blown-in insulation

• Insulation material: Loose cellulose or fiberglass that’s blown into attics
• Location: Attics and some walls where there’s no existing insulation
• Use: Loose insulation fills in around odd shapes and cavities to help with conduction and convection

Spray foam insulation

• Insulation material: Expanding foam enlarges as it cures; other types cure in the shape they’re sprayed
• Location: Where pipe or wires enter a house and around windows where batting can’t reach
• Use: Plugs hard-to-fill gaps, preventing conduction and convection heat loss

Rigid foam insulation

• Insulation material: Sheets of extruded or expanded polystyrene
• Location: Tucked between joists above the basement or crawlspace
• Use: Foam boards insulate while providing a partial vapor barrier

Specialty insulation

• Insulation material: Pipe insulation, duct insulation and water heater jackets
• Location: Around objects that store or distribute hot water and indoor air
• Use: Keeps water hot; insulates ducts that pass through cold attics

How to tell if you have insulation

It’s possible you don’t even know if you have insulation. The only way to know for sure—and to figure out what kind of insulation you have—is to look for it. Use the table below (courtesy of the Oak Ridge National Laboratory) to know what you’re looking at.

How to check for roof or attic insulation

Your home almost certainly has some existing insulation in the attic. It’s easy to check because it’s normally just out in the open. Go (or peek) into your attic and take a look. 

If you have access to the ducts in your roof or attic, you should also check those for insulation. Ducts move air around your home, and if they’re not insulated, you’ll never be able to get the full power from your AC or heater. An insulated duct will have a squishy reflective wrapping around it. 

How to check for wall insulation

It’s not obvious how to look inside a wall. Generally, it’s recommended that you take the cover plate off an outlet and peek in there with a flashlight—just be sure to turn off the power to the associated outlets first.

If you see any fibers or foams inside, you have insulation for that part of the wall. Keep in mind that some walls might have insulation while others don’t, so you’ll want to check all external walls and the wall connecting your home to the garage (or other areas where you don’t control the temperature). 

How to check for floor or crawl space insulation

If you’re able to check under your floors for insulation (by pulling up a floorboard, for example), you’ll be looking for the same fibers or foams. If you have a crawl space with ducts under your home, check those too.

How much insulation do I need?

Depending on what part of your home you’re insulating and what climate you live in, you’ll need different amounts and types of insulation. For starters, you’ll need to calculate the total R-value of your insulation: that’s a measurement of how easily heat will move through the material.

To get the R-value, you’ll have to measure the depth of the existing insulation in inches and use the formulas in the insulation R-value chart below. 

Once you have that information, use this map and table from the Department of Energy that shows the suggested R-value for insulation based on your climate.

How to insulate: hire or DIY?

You can install insulation on your own, but it’s not simple—or particularly safe. Many types of insulation are irritants to human skin (such as fiberglass), and others can cause dangerous vapors to form when they’re installed (such as polyurethane foam). You might run into asbestos, and incorrectly installed insulation can be a fire hazard and actually decrease air quality in your home. 

If you’re somehow still excited to try it yourself, make sure you have personal protective equipment (PPE), including gloves, masks, and even respirators. For more guidance, here’s a guide from EnergyStar and another from the Insulation Institute.

If you plan to hire a contractor, check with your local utility or government—they might have existing programs to help homeowners find quality contractors, and they may even cover part of the cost of installing insulation.

Learn how else you can save energy

We’re on a mission to help homeowners dramatically reduce the amount of energy they use. If your interested in saving money and doing something good for the planet in the process, check out one of our other guides:

• How to save money and energy by switching to a heat pump
• How much can you save by switching to LED lighting?
• How to save energy by replacing your water heater

The post Everything You Need to Know Before Upgrading Your Home Insulation appeared first on Carbon Switch.

In addition to wasting money, poorly insulated homes are just less comfortable. They’re drafty and difficult to keep at the right temperature, which results in a home that’s too cold in the winter and too hot in the summer. 

Improving your home’s insulation is a great way to save money, improve your comfort, and cut your carbon footprint. Depending on where you live you could save between $200-500 on your utility bill and cut your carbon footprint by 500-1,000 kilograms (0.5-1 metric ton) per year.

In this guide, we’ll help you understand how much you can save based on where you live and how to get started without breaking the bank. If you’re ready to work on an insulation project, check out our insulation buyer’s guide.

How much does insulation cost?

The cost and savings from insulating your home depend on a few different factors: your climate, the age of your home, and existing insulation. 

Climate

What insulation you need—and therefore what it’s going to cost—is almost entirely based on your local climate. Hotter climates will be able to get by with minimal insulation by stopping air leakage, while houses in colder climates will require more insulation (in addition to modifying the home to stop air leakage). 

This map by the Energy Department is a good place to start to understand how much insulation you need. If R-values don’t mean anything to you, check out our insulation buyer’s guide. 

Age of the house

As with most things home ownership, the older your home, the harder—and more expensive—it will be to install insulation. There are a few reasons:

• Older homes were often built without any insulation, so in order to install what is currently recommended for your climate, you may need to substantially retrofit your home to make room for it. If that’s the case, you’ll need to consider the costs of that project on top of the cost of insulating.
• If you have an older house, you’ll also want to have an electrician involved: adding insulation to a home with aging electric wiring may be a fire hazard. (Never a dull moment with old homes.)
• Houses built before 1978 might have asbestos in them, and if you’re digging into the walls for insulation, that will require specialized removal and will increase the cost. 

Size of the house

The bigger the house, the more it’ll cost to insulate. Simple as that. You’ll need more insulation, and it’ll take longer to install, so it’ll be more expensive. 

The main reason for this is that insulation is priced per square foot and takes quite a bit of manual labor to install. 

Existing insulation

What insulation you currently have will impact the cost of upgrading. Modern insulation (in the form of fiberglass) was only invented in 1932—homes older than that used anything from horse hair to newspaper for insulation. Hopefully some previous owners took care of that and you don’t have horse hair in your walls, but stranger things have happened in old homes.

Upfront insulation costs

Improving your insulation isn’t as expensive as switching to a heat pump HVAC system, but it’s more definitely a bigger investment than small energy efficiency improvements like installing LED lighting.

Your upfront costs will depend on all the factors listed above: an old home in a cold climate with minimal existing insulation will cost the most; a newer home in a warm climate with decent existing installation will cost the least.

But it’s helpful to at least have a baseline estimate. So we analyzed data from the Energy Department to estimate how much the average insulation project costs in each state.

So what are you paying for when you invest in upgrading your home’s insulation? Generally the costs can be broken down into three categories:

• The insulation itself
• The labor cost to install it (if you’re hiring someone to do it)
• Any additional parts needed to install or optimize the insulation

Unit costs of insulation

Insulation is usually quoted per square foot. Depending on what insulation you want, the cost per square foot can range anywhere from $0.20 to $2.00, so if you have a big house, the type of insulation will drastically change your cost.

Take a look at the table below from the Energy Department for estimated costs of various types of insulation. If you don’t know what type of insulation you need, read our insulation buyer’s guide.

Labor

You’ll be paying whoever installs your insulation. It’s a highly specialized skill and not without risks, so this can be expensive. You’ll want to call around for several quotes before picking a contractor.

Additional parts

If you’re installing it yourself, you won’t have to pay for labor, but it’ll come with other costs. You’ll need personal protective equipment (PPE) such as gloves, masks, and sometimes even respirators. Why? Because many types of insulation, like fiberglass, are irritants to human skin, and others, polyurethane foam, can cause dangerous vapors to form when they’re installed.

You might also need to pay for things like radiant barriers, moisture barriers, pipe blankets, ducting insulation, and foil tape. These help either protect the insulation or help the insulation work better by limiting heat loss/gain. 

Savings from insulating your home

So how much can you expect to save after you improve your home’s insulation? Once again, that will depend on where you live, the size and age of your home, and the existing insulation. 

But averages can be a good place to start. So we crunched some data from the Energy Department to create this table that shows the average annual savings you can expect in each state, based on the type of insulation project.

In addition to saving money every month on your utility bill, you’ll also save money whenever you replace your home heating and cooling system (ideally with an energy efficient option like a heat pump). That’s because the better your insulation, the smaller your heating and cooling system needs to be. And the smaller the system, the lower the upfront cost.

Carbon footprint reduction from insulating your home

In addition to saving money, you can also reduce your carbon footprint a lot by insulating your home. That’s because less energy (whether it’s electricity, gas, or fuel oil) means less carbon emissions. 

We analyzed data from the Energy Department to estimate how much the average insulation project can reduce a homeowner’s carbon footprint in each state based on the type of project. (The table shows the kilograms of CO2 emissions per household per year).

If you’re looking for other ways to cut your carbon footprint check out these other guides we produced:

• How to save money and energy by switching to a heat pump
• How much can you save by switching to LED lighting?
• How to save energy by replacing your water heater

Energy audit for insulation 

Before you go out and buy insulation or hire a contractor, it’s worth getting an official energy audit from someone using the Manual J standard from the Air Conditioning Contracts of America (ACCA, the official trade group for space heating and cooling in the United States). 

This energy audit will find your exact heating and cooling needs using the industry standard method and will be able to find the exact type of insulation you currently have and what you need for your specific area—and how much of it.

Sometimes the audits will be provided for free by your local utility or government, or even as a complimentary service from the contractor you plan to work with. Other times, you’ll have to pay for it. 

Here’s the program for my local utility as an example. It provides the audit (which includes recommendations for sizing) for free, and it provides rebates if you work with one of their vetted contractors.

Utility and government programs for insulation rebates

Your local utility has as much of an incentive to cut your home energy use as you do. Yes, it means they’re able to sell you less energy, but to the provider, it’s worth more today to avoid the potential costs of producing more energy. Energy efficiency allows the utility to continue to run the power grid with the existing power plants and lines even with population growth, and not have to make costly investments in new power plants or power lines that may not pay for themselves for decades.

In part because of this, all utilities run some sort of residential energy efficiency program to help offset some of the costs of retrofitting or upgrading your insulation. These programs can either be tax credits from your state or local government, rebate programs where you can mail in proof-of-purchase to get money back, or programs where the utility vets local contractors and helps cover the cost of installation.
You can use this link to see what program, if any, your utility is running for insulation. You can also search online to see if a local organization is running weatherization or building envelope programs—those are different terms for installing or upgrading insulation.

Read our other guides

We’re on a mission to help homeowners dramatically reduce the amount of energy they use. If your interested in saving money and doing something good for the planet in the process, check out one of our other guides:

• How to save money and energy by switching to a heat pump
• How much can you save by switching to LED lighting?
• How to save energy by replacing your water heater

The post How to Save Money and Energy Insulating Your Home appeared first on Carbon Switch.