Y'all know I'm all about useful alternatives in church life. And history. And to a lesser degree, Georgia, where you'll still find tin-roofed houses. Not tin really but corregated iron: a cheap, if down-market, resource.
Thus I was tickled to discover this British (and elsewhere) use of "tin tabernacles": buildings meant to be temporary home for new congregations -- some are now a century or more old, though few that survive are still used as churches. A few that do are Unitarian. They were made from kits, and could be quite decorative.
But there was no article about them at Wikipedia, so I just wrote one, my first.
If you know anything about them, go and edit or add to my stub of an article.