Once your home is built, it is a challenge, a significant expense and inconvenience to change out its insulation. So, while you’re in the planning and construction process, it’s vital to get your insulation just right to keep your home energy efficient and comfortable. These days, people rightfully expect great energy efficiency from their homes, to make keeping it cool in the summer simpler and to keep their utility bills low. We believe that a high-end home should surpass your expectations and should have a high-end function as well as beauty. To that end, we spend time with our clients, walking them through their insulation options. Here’s a guide to the best insulation options for new home construction.
California’s Requirements
As always, we start with the building code requirements for your home, as they are the minimum standards we have to meet or exceed. The U.S. Department of Energy has divided California up into several climate zones, each of which requires a different R-value for ceiling and wall insulation. R-value is a measurement of how much heat resistance insulation has. That is, how much heat it keeps out of the home or inside of the home (depending on the season). The higher an R-value, the better the insulation.
In San Jose, we are in Zone 4. If you are slightly outside of San Jose, you may be in Zone 3 or Zone 12. Zone 3 is closer to the coast, and Zone 12 is to the North and West. According to California’s Title 24, in Zone 4, ceiling insulation must have an R-value of 38, and wood frame walls must have insulation with an R-value of 25. It may also be helpful for you to know that the building codes require a glazing U-value of 0.38. In Zone 3, requirements are almost the same except that the glazing U-value is slightly higher, at 0.42.
What about if you are in Zone 12? Ceiling insulation needs a higher R-value, of 49, and wall insulation also needs a higher R-value of 29. The glazing U-value, however, is the same as is required in San Jose.
Most Common Insulation Choices
Now that you understand the most basic R-value your insulation needs to achieve, you can better understand your choices.
Loose-fill: This type of insulation is simply poured into the wall cavities. It may be cellulose or fibreglass, and we discuss the main differences between those two materials below.
Blown-in: Blown-in insulation can be more tightly packed than loose-fill, but it does come with a downside, in that the ceiling and wall cavities must be connected in order for the blow-in to reach both spaces.
Spray foam: Spray foam insulation is sprayed into place, where it expands to fill any small nooks or crannies. This makes it useful insulation for custom homes with unusual shapes.
Batts and rolls: This insulation is like sheets of fiberglass that we can roll out into the wall as if they are sleeping bags. Batts and rolls are time-consuming to install, and their seams can cause problems. However, they can be affordable and can offer great performance.
Rigid foam board:This insulation is more common in commercial applications, but still highly useful for specific residential applications. If you want cathedral ceilings or other features that reduce the space in your ceiling or wall, rigid foam board is a thin material that will still fit in the space without sacrificing R-value.
Cellulose versus Fiberglass
These materials may be either loose fill or blown in. Cellulose is the least expensive, but it settles and provides worse coverage and performance than many other insulation types. Fiberglass, an upgrade from cellulose, is the most common insulation material in the United States. It balances affordability with performance. It provides sound insulation too, which is useful for musicians, those who work from home, or those with children.
Custom Options for Your Insulation
At Fernandez Designs and Builders, we are always looking for a niche, truly unique option to bring to our clients. Your custom home should be just that, custom. You shouldn’t be limited to just selecting between two or three insulation options. We can help you explore more unusual insulation options that might help achieve your specific goals for your home, such as using local, recycled, or environmentally friendly materials. Here are just a few options you may want to consider:
Denim: This insulation is recycled cotton or jeans with added plastic fibres for strength. It reduces the risk of mildew and mold, and can achieve a great fire-rating, depending on the specific product you choose, of course. Moisture resistance means that it does not require a moisture vapor, which can help reduce costs. Plus, you can feel great about the health of this product, because it does not off-gas formaldehyde, unlike some other insulation options.
Lycnene: This material is made from castor oil into spray-foam type insulation. It is an expensive option, but only because it is so effective as insulation and at reducing noise transfer in your home. If you’re building near a big source of noise, like a highway, this might be a great option for you.
ThermaCork: Those who are personally invested in reducing their carbon footprint will be thrilled to discover this insulation. It is made from the bark of oak trees, so it is completely renewable. It is carbon negative and so efficient at insulating that it can be used for passive houses, which don’t use air conditioning or furnaces to moderate their temperature.
Aerogel: If you need a high-performance insulation that can fit into smaller places than ThermCork can, Aerogel is a great option. This material is made by super drying liquid from a gel. The result is just the structure of the gel, so it looks translucent but resists heat incredibly.Aerogelisn’t often used in residential applications, but it can be useful for new builds and to retrofit older homes to be energy efficient.
Curious about what other insulation options you might have? Fernandez Designs and Builders will walk you through your options, and search out unique materials if you need them. Learn more about our custom homes or call today to get started.