What makes a tiny house a home? Proper insulation, to keep you toasty in the winter and cooler in the summer. Insulation creates energy efficiency as well as helps control temperatures in your home. In a tiny house on wheels, there's insulation in the trailer, walls and roof.
There are many options for insulating your home, and that's where you will need to consider various factors including cost, your construction experience, and desire for organic materials. In each case, the thickness and insulation material matter as they combine to contribute to overall energy efficiency.
Denim is a terrific recycled insulation, now available in stores.
Tumbleweed's ready-made homes are built with stick (2-by-4) construction. Our builders use polyurethane spray foam, a high density closed-cell foam which seals tight the walls and roof. Ready-mades have an R-20 insulation factor exceeding that of any RV and many normal residential homes. Installing this foam is a pricey proposition and requires some expertise. We recommend hiring an expert if you go this route, although DIY kits are gaining popularity.
You do have insulation choices beyond spray foam. Fiberglass batts are most commonly used by tiny house builders and, with sufficient thickness, provide excellent insulation. While fiberglass may feel scratchy and irritate installers, there aren't issues after it gets enclosed within walls.
The most popular trailer insulation is EPS (extruded polystyrene), a foam closed-cell structure with consistent skin. Typically three inches of rigid foam board is used in the trailer, before the sub-flooring is installed.
New SIP (structural insulated panel) walls and roofs are another approach. Rather than using stick construction, you measure and order pre-cut panels which include foam insulation encased by OSB (oriented strand board).
Of course, sheep wool works well for clothing. It's also an organic material that gets used for housing insulation, though often gets treated with borax (from mining) as a fire retardant and insect/pest repellent. See wool batts installed at Wool Shepard Insulation.
This insulation is made from volcanic diabase rock, that's crushed, mixed with coke and slags, then melted in a furnace. Afterwards it resembles wool in its appearance. This insulation claims to prevent rot or vermin problems. Please check out Roxul batts.
Wet spray cellulose, made from newspapers, has similar insulation factors to sheep and stone wool. It requires a high-power blower to install correctly, and then needs to dry out. With a difficult (to get right) process, we don't recommend it for tiny house builders.
Last and definitely not least, consider blue jeans as an alternative insulation material. Denim insulation is recycled from textile fibers and there are no chemical irritants either. To see an example, check out Ultra Touch here.