When it comes to insulation materials we recommend that you consider only the ones that have been thoroughly tested in the United States. There are many new materials that claim to be eco-friendly, green and healthy for you but will not last for the life of the building. Bottom line – if it hasn’t been around for long and wasn’t tested over time we recommend you not to choose it. The 4 insulation materials you should consider are Fiberglass, Cellulose, Mineral Wool (rockwool) and Polyurethane Spray Foam.