Insulation Buying Guide
A quick guide to strategic product selection

 
What to look for

1. Efficiency: the efficiency of insulation is measured using R-value. R-value measures a product's thermal resistance effectiveness, or its ability to keep hot air in and cold air out. The higher the R-value, the more effective the product. Recommended R-value depends on your local climate. Contact Eco-innovations for more information or visit ENERGY STAR's Recommended Levels of Insulation webpage.
    
2. Toxicity: certain types of insulation, like fiberglass for example, may contain toxic material (formaldehyde) that can off-gas over time. Other, more innovative yet effective types of insulation, like cellulose, are non-toxic. See below for details.
    
3. Environmental impact: some types of insulation make use of pre- and/or post-consumer recycled material (e.g. cotton fiber insulation made of recycled denim) while others must use virgin materials in their production. Products that utilize material which would otherwise be placed in a landfill help mitigate the consumption of new products, thereby lessening impact on the environment.
    
4. Cost: the cost of the insulation product plus the installation of the product are always important factors to consider. Eco-rate allows you to compare the economic and environmental costs of insulation types ranging from fiberglass to cellulose to spray foam (installation cost is not included in our price analysis since such expenses vary so greatly across the U.S.).
   

► View our Insulation Compare Technology page to see how the various insulation materials compare to one another in terms of efficiency, toxicity, environmental impact and price.

Types

Cellulose

Contents & application

• Cellulose derives from recycled wood fiber, most commonly in the form of recycled newspaper
• Can be blown-in as loose fill into attics and closed wall cavities or damp-sprayed into open wall cavities

Efficiency

• Approximate R-Value = R-3.6 per inch of thickness when densely packed at at least 2.5 lbs. per inch (takes into consideration settling-in effect)
• Because of its method of installation, it seals cavity spaces effectively, greatly reducing air infiltration and providing a superior barrier to sound
• It can absorb water, which could be a problem if a water leakage from the outdoors occurs
• It does settle over time (be sure to mention the settling affect to your installer so that he/she assures you that this will be compensated for with added insulation)

Toxicity

• Non-toxic
• Will not emit harmful gases
• Does not contain formaldehyde
• Treated with non-toxic borate for fire, mold and insect resistance
• Takes less energy to make than any other insulation (made in electrically-driven mills at about 750 BTUs per pound, in contrast to the manufacture of fiberglass insulation, which consumes 6,000 - 15,000 BTUs per pound)

Environmental impact

• Has the highest level of recycled content in the insulation industry - up to 85% (fiberglass has a maximum of 40% recycled content and foam products have little or none)
• Is made with post-consumer recycled paper that would otherwise end up in a landfill
• Can be recycled or composted at the end of its useful life
• Takes less energy to make than any other insulation material; known as "embodied energy" and includes the total energy required to transport raw materials, manufacture and distribute the product

Cost

• Cheaper than sprayed foam insulation
• Can be more expensive than fiberglass

Cotton Fiber

Contents & application

• Typically consists almost entirely of natural denim and cotton fibers that are 100% recyclable
• Available as batts (does not itch, is non-toxic and is easy to install)
• Provides an effective noise barrier and resists microbial growth

Efficiency

• Approximate R-Value = +/- R-3.75 per inch of thickness

Toxicity

• Contains no material with harmful off-gassing properties (e.g. VOCs)
• Treated with borate to prevent fire and pests

Environmental impact

• UltraTouch consists almost entirely of natural denim and cotton fibers that are 100% recyclable and obtained from post-consumer material, reducing landfill waste and the need to use virgin materials

Cost

• Moderate

Fiberglass

Contents & application

• Composed of natural ingredients such as sand and recycled products such as window glass and bottles; ingredients are melted and spun to create small strands of fiberglass that together form "glass wool"
• Available as board, batt, and loose fill (BIBS blown-in)

Efficiency

• Approximate R-Value = +/- R-7 per inch of thickness (high-density batts only)
• Does not settle over time
• Is not absorbent and, if exposed to moisture, will not wick up or hold water
• Blankets do not seal wall and ceiling cavities tightly (spray does)

Toxicity

• Releases eye, throat and skin irritants
• Contains formaldehyde unless certified by the GreenGuard Environmental Institute for low emissions of formaldehyde and other pollutants

Environmental impact

• Requires an energy-intensive manufacturing process
• Contains up to 40% recycled content (most manufacturers use 20%–30% recycled glass content)

Cost

• Low

FOAM

Contents & application

• Made primarily from raw materials of petroleum or other hydrocarbon origins (soy-based is partially made from soy beans)
• Generally 5 types: cementitious (e.g. Air-Krete™), polyurethane, soy-based polyurethane, polyisocyanurate and policynene (e.g. Icynene™)
• Two application types: spray foam and rigid foam
• Water-vapor permeable, remains flexible, and is resistant to wicking of moisture
• Liquid foam insulation, combined with a foaming agent, can be applied using small spray containers or in larger quantities as a pressure-sprayed (foamed-in-place) product; both types expand and harden as the mixture cures and conform to the shape of the cavity, filling and sealing it thoroughly
• Blown-in application fills even the smallest of cavities and is quick to install (requires installation by certified experts)
• Can be sprayed through small holes in walls
• Adheres to the surrounding structure - no settling and no air gaps (great for irregularly shaped areas and around obstructions, attics and wall cavities)

Efficiency

• Approximate R-Value = R-6 to R-9 per inch of thickness (depending on type)
• A very effective  insulator: has twice the R-value per inch than traditional batt insulation

Toxicity

• Depending on type, can contain HCFCs and/or CFCs unless specified to be free of these toxins
• Depending on type, can be quite toxic during installation (respirators or supplied air required)

Environmental impact

• Petroleum and/or other hydrocarbon origin increases our dependence on oil, a non-renewable, finite resource
• Not recyclable - must be placed in a landfill at the end of its useful life

Cost

• Two to three times more expensive than conventional fiberglass and cellulose insulation

SLAG WOOL

Contents & application

• Consists of iron ore blast furnace slag, natural rock, PF binder

Efficiency

• Approximate R-Value = R-3 - R-7 per inch of thickness

Toxicity

• Releases eye, throat and skin irritants
• Contains formaldehyde unless certified by the GreenGuard Environmental Institute for low emissions of formaldehyde and other pollutants

Environmental impact

• Requires an energy-intensive manufacturing process (high embodied energy)

Cost

• Moderate

SHEEP'S WOOL

Contents & application

• Consists of sheep's wool, a rapidly renewable resource
• Typically comes in the form of a batt

Efficiency

• Approximate R-Value = R-6 per inch of thickness

Toxicity

• Non-toxic

Environmental impact

• Wool is a rapidly renewable resource (i.e. it can be harvested again/replenished within 10 years time)

Cost

• Fairly expensive (approximately $3/square foot installed)

Airtight Building with ICFs and SIPs

An airtight building method uses airtight structural elements such as structural insulated panels (SIPs), insulating concrete forms (ICF), and concrete masonry units to replace some or all of conventional stick framing elements.

SIPs are high performance building panels used in floors, walls, and roofs for residential and light commercial buildings. The panels are typically made by sandwiching a core of rigid foam plastic insulation between two structural skins of oriented strand board (OSB).

ICFs are rigid plastic foam forms that hold concrete in place during curing and remain in place afterwards to serve as thermal insulation for concrete walls. The foam blocks, panels, or planks are lightweight and result in energy-efficient, durable construction. Homes built with ICF exterior walls require an estimated 44% less energy to heat and 32% less energy to cool than comparable frame houses. ICFs also reduce the demand for wood derived from virgin sources. That being said, ICFs are made of a lot of foam, which requires the use of petroleum or other hydrocarbon based raw materials (with the exception of Durisol).

► View our Insulation Compare Technology page to see how the various insulation materials compare to one another in terms of efficiency, toxicity, environmental impact and price.

Buy local

Look for insulation products that are manufactured near you, at least within 500 miles. This reduces carbon emissions associated with product transportation and supports your local economy.

Questions? Feedback?

Visit our Forum to ask questions and share your thoughts about eco-friendly and cost-effective insulating products.

This product is eligible for 0.5 point under the LEED for Homes MR 2: Environmentally Preferable Products credit.