Late last spring, my husband Dave and I decided we wanted an outdoor pizza oven. Throughout June, we did a fair amount of research, online and locally, and found many wonderful options, but all of them were way, way out of our price range. We hadn't even formulated a budget for The Oven at that point, but we knew that we weren't willing to spend $7K-15K just to cook pizza outside.
Dave originally envisioned a brick oven, and he thought maybe we could build that ourselves; we're a very Lego family, how hard could it be? He did some more research, and it turns out: very, very hard. Something about masonry skills, and us not having them.
Eventually, we came across a building technology so simple that even a caveman could do it (literally). Ten thousand years ago, people were building all kinds of things out of adobe (clay + sand) and insulating with cob (clay + sand + straw).
We were interested in working with these materials, but it sounded disconcertingly primitive. Plus, we really had no idea how to work with it, and it's not like we could call the Stone Age helpdesk for advice on what they'd done. So we did what we always do: we thought about it for awhile.