Innovations in technology and infrastructure have given rise to McMansions in America over the last few decades, but as the old adage goes, bigger isn’t always better. That’s the thinking behind the recent trend toward tiny homes, spearheaded by citizens who want to live more simply on less. And given the recent housing bust — nearly 1 out of 4 Americans now owes more than their house is worth — smaller doesn’t just seem smarter. It’s more sustainable, too. Here’s a look at how seven microhome communities are challenging our traditional approaches to housing — and helping tackle big problems along the way.