To create living spaces that are both sustainable and livable, designers are looking outside the box for building materials.

Building a green house can mean many things: in some cases it means incorporating energy efficient features into the design, and for others it means designing a self-sustaining system that allows the home to operate off the grid.

But most would agree that to build a truly green house, you have to start with sustainable materials. Leave the straw, sticks and bricks to the Three Little Pigs. We scoured the internet to find some of the most amazing sustainable houses built out of some truly surprising things.

Hemp House  - Push Design

There are over 25,000 different uses for hemp, and in the past, it's been incorporated into sports cars, clothes, and biofuels. But building an entire house out of it? Push Design, an Asheville, NC-based sustainable design & development company is the first in the nation to build a home out of hempcrete, a concrete alternative that's been used in Europe and Australia since the 1960's (also see top image). Push Designers describe the Tradical Hemcrete material used in the North Carolina house:

It is a breathable, natural and toxin-free system that boasts a 2.4/in R Value, and the material actually helps filter the air for maximum indoor air quality. It is estimated that one house built with hemp is the equivalent of ten acres of trees in terms of the carbon sequestered.

Recycled Beer Bottles - Tito Ingenieri

If you think taking your recycling to the curb completes your eco-friendly requirements for the week, think again. Argentinian designer Tito Ingenieri spent 19 years saving over 6 million beer bottles so that he could build himself a giant house in Quilmes, Buenos Aires. The bottles are incorporated into walls, windows, and even exterior decorations, like this bike-shaped light catcher (below).

Rubber Car Tires - Earthship

In the year 2003, the U.S. alone discarded over 290 million scrap rubber tires. Although some are retreaded, or upcycled into planters and other creative items, the vast majority of these tires end up in landfills or illegally dumped in vacant lots. That's why one innovative family decided to use these readily available tires to build themselves a unique home known as an Earthship (a passive solar home made of recycled and natural materials, that's usually off-the-grid).

The home's designers say: "The interior walls are made of tires filled with dirt (below). They’re then covered in concrete and stucco.  These walls always feel nice and cool in the summer.  In the winter, they absorb the heat from the sun, making your nights a little cozier."

Bonus!

For those of you who might be interested in building your own house out of unlikely green materials, check out this Instructable guide to building a house out of used plastic bottles, and read this great Cleantechnica article about why your next house might be built of corn.

Image Credits: Push Design | Elmurocultural | Making This Home