We've gathered some of our favorite small, passive, and sustainably designed homes on our Pinterest and wanted to share a few of our favorites here on the blog. From reclaimed materials to solar panels, these homes boast innovations that minimize their ecological footprint. The trend of building more sustainably has picked up speed significantly in the past decade. By 2008, 15,000-20,000 Passivhaus (the most rigorous, voluntary standard for energy efficiency in a building) buildings had been built around the world. We're in awe of the innovations in design and construction that enable a more ecological homestead.