5 Types of Sustainable Home Insulation

One of the oldest and most environmentally friendly insulation materials, made primarily from recycled newspaper and other paper products and treated with non-toxic fire retardants like boric acid. It's composed of up to 85% recycled content, biodegradable, and has a high R-value of around R-3.2 to R-3.8 per inch, making it excellent at filling irregular cavities and reducing air leaks — ideal for attics, wall cavities, and retrofitting existing structures.

A natural, renewable, biodegradable material that's becoming increasingly popular in modern sustainable building. It's naturally flame-retardant and pest-resistant when properly treated, with an R-value of around R-3.5 per inch, and it's effective at absorbing and releasing moisture without losing its insulating properties — great for walls, ceilings, and floors in both new builds and renovations.

Often made from recycled denim and other cotton fabrics, containing up to 90% recycled content and free from harmful chemicals and formaldehyde. It has an R-value of about R-3.5 per inch and offers good sound insulation alongside thermal performance — ideal for interior walls, ceilings, and spaces that need noise reduction.

Harvested from the bark of the cork oak tree without cutting it down, making cork renewable and biodegradable, plus naturally mold-resistant and insect-repelling. With an R-value of about R-3.6 to R-4.2 per inch, it provides excellent acoustic and thermal insulation — good for floors, walls, and exterior insulation systems.

Made from the fibers of the industrial hemp plant, which grows quickly with minimal water and no pesticides and absorbs more CO2 during growth than it emits during production. Fully recyclable and biodegradable, with an R-value of around R-3.5 to R-4 per inch and natural resistance to pests and mold — suited to walls, roofs, and floors in residential and commercial buildings.

Choosing sustainable insulation is a smart move for homeowners looking to reduce their environmental footprint and improve energy efficiency. When selecting insulation, consider climate, budget, availability, and the specific area you want to insulate — a green building professional can help guide you toward the best option for your needs.