This build is for under ground and you need to be at least 15 blocks down from the surface with all areas surrounding the build 15 blocks area need to be golum proofed by closing holes that they can spawn in. In this build if one chooses to bring in a zombie to convert the villagers so that you can convert them back for cheaper prices it is a bit easier to do so than my original build.

REV: Widened walkway, added signs and barrels and made it where you can access the villagers when they are asleep. Closed a Golum spawn area.
Corrected a bad schem save.