EPA estimates that homeowners can save an average of 15% on heating and cooling costs (or an average of 11% on total energy costs) by air sealing their homes and adding insulation in attics, floors over crawl spaces and basements.
According to the EPA, it's estimated that homeowners can save an average of 15% on their utility bills after adding insulation to their homes. In California, one person uses an average of 572 kilowatt-hours (kWh) per month and pays an average price of $0.2245 per kWh.
Benefits of upgrading insulation in an older home
The most significant advantage is improved energy efficiency, which can lead to substantial cost savings on heating and cooling bills. Properly installed and effective insulation can reduce energy usage by up to 20%, making it a worthwhile investment for any homeowner.
While both types provide insulation, R30 is the better option for maximizing energy savings in areas where heat loss or gain is a major concern. For example, R19 may suffice for interior walls, but R30 is more appropriate for exterior-facing attics or floors.
However, insulation can start falling from fiberglass batts after 15 to 20 years, so if your insulation was installed in batts well over a decade ago, it might be time for an inspection or a home energy audit.
The Big Question: Do I Need to Remove Old Insulation Before Installing New? In the majority of cases, removal of old insulation is NOT necessary before adding new.
EPA estimates that homeowners can save an average of 15% on heating and cooling costs (or an average of 11% on total energy costs) by air sealing their homes and adding insulation in attics, floors over crawl spaces and basements.
You will want to bring up your attic up to R-38:
If your attic has 5-6″ of existing insulation, you'll want to install an R-19 to achieve a total of R-38.
The dip from R10 to R4 seems odd, as one would expect more R as you travel further north through the zones. Thicker is not better! Doubling the amount of insulation will double the R-Value, but so what? Doubling the insulation from R-19 to R-38 does NOT cut the heat loss in half (50%) it cuts it by around 3%!
The DOE Insulation Fact Sheet (DOE/CE-0180) can be ordered from the Energy Efficiency and Renewable Energy Clearinghouse or accessed from the Internet at www.ornl.gov/ roofs+walls. Fiberglass and rock wool batts—2x4 walls can hold R-13 or R-15 batts; 2x6 walls can have R-19 or R-21 products.
While over-insulated attics aren't as common as under-insulated attics, it is possible to put so much insulation in your attic that it has a negative impact.
Many older homes have less insulation than homes built today, but even adding insulation to a newer home can pay for itself within a few years. To determine whether you should add insulation, you first need to find out how much insulation you already have in your home and where it is.
National average costs for attic insulation range from $1 to $6 per square foot if you're planning to have it installed professionally.
Irritation to skin and respiratory system
Wall insulation solutions like Rockwool are made of ultra-fine fibres. While thermally efficient, they can cause skin and respiratory irritation.
If you live in the Southern part of the U.S., the recommended insulation level is a minimum of R-38 or about 13-14 inches of insulation. If you live in the Northern part of the U.S., the recommended insulation level is a minimum of R-49 or about 16-18 inches of insulation.
How many degrees of difference insulation makes on its own depends on the type of home you have, what the weather is like and what kind of insulation you have. Depending on what you choose, you could see a five- to 20-degree temperature difference just based on the insulation alone.
R19 Insulation offers superior thermal insulation compared to R13. With a typical thickness of 6.25 inches, R19 fiberglass is designed for use in 2x6 wall cavities, making them suitable for colder climates where higher thermal resistance is necessary.
The optimal R-value for most homes is 30, but you can go as high as 38 if you live in a tropical climate. Anything higher than 38 indicates an over-insulated space.
Because its structure is more complex than single-layer insulation, the cost is relatively high. Additionally, in some cases, double-insulated cables may fail due to spalling between the inner and outer insulation layers.
Also, when laying down additional insulation, work from the perimeter toward the attic opening. Never lay insulation over recessed light fixtures or soffit vents. Keep all insulation at least 3 inches away from recessed "can" lights, unless they are rated IC (Insulated Ceiling).
The U.S. Department of Energy recommends attic insulation levels of R-49 to R-60 for most homes in colder climates, and R-30 to R-49 for homes in warmer climates.
R-21 insulation achieves its superior performance with minimal difference in thickness compared to R-19, to make it ideal for applications where space is limited.
While loft insulation is an effective way to improve energy efficiency and reduce heating costs, over-insulating can lead to several potential issues. Firstly, over-insulation can lead to poor ventilation in the attic, which can cause moisture buildup and increase the risk of mould growth.
The Types of Insulation That Have the Highest Resale Value
However, according to a study by the National Association of Realtors, insulating attics and walls with cellulose or fiberglass can have the highest return on investment at 107% and 95%, respectively.
In fact, cellulose has the highest rate of settling rates, ranging from 13 to 20% after installation. This settling continues for weeks, months, and years after installation, and if not addressed properly during the insulation, it can cause serious energy efficiency issues.