The innovative company Ecovative recently “grew” their first tiny house. Or more precisely, after putting together the pine walls of the tiny house, they filled it with the so-called Mushroom Insulation. This insulation proceeded to literally grow in place inside the wall cavities, which already contained all the wiring and plumbing. In this way, the insulation actually glued together the pine boards used to build the framework of the house. The house measures around 62 square feet and is mounted on a trailer so it can be transported anywhere. The tiny house is a prototype and a test of Ecovative’s Mushroom Insulation and they are currently touring the country showing their creation.



To grow this insulation in place, the company used mycelium, which is the vegetative part of a fungus and consists of a mass of thread-like hyphae, as a replacement for traditional insulation. When bonded together with agricultural waste and byproducts like corn stalks, mycelium creates a material that can effectively replace plastic foam insulation. The company has been selling this product for years to companies looking to replace Styrofoam (EPS) packaging with a more sustainable, organic alternative, and they have now branched out into providing it as a natural form of home insulation.

This insulation process works because mycelium, or Mushroom Insulation grows into wood forms in just a few days, and creates an airtight seal in the process. It takes another month for this type of insulation to dry, and the resulting wall is airtight and structurally very strong. This type of insulation can save a lot of money, and give the house where it was used a great thermal performance, since it represents one continuous insulated wall assembly. This type of natural insulation board has a Class A fire rating (ASTM E84) without the use of any fire retardant chemicals. The insulation also has very low VOCs (ASTM E1333), and competitive R-values, which will not decrease over time, as is the case with standard insulation.

Ecovative also produces a number of other sustainable and high-performing materials for construction of homes. Apart from the grow in place Mushroom Insulation, they also offer rigid board insulation panels, while they are also planning to begin producing SIPs with a mycelium grown core, which will be much healthier, safer, and environmentally-conscious than synthetics.

Their Myco Foam Insulated Sheathing is designed to be used on new construction or retrofits, and meets the building code requirements for continuous insulation and all deep energy retrofit goals. This type of continuous insulation raises thermal performance without the need for thermal bridging, while it also provides a continuous air barrier for increased energy efficiency. The company also offers Mushroom Acoustic Panels, which have no VOC emissions or chemical binders, and provide great sound dampening.

Ecovative is selling DIY kits for constructing your own mushroom insulated tiny house from scratch on their website for around $10,000.