I get emails all the time from people hoping to solve the post-disaster shelter and housing problem by 3D printing houses.
Instead, if you have to 3D print something, how about:
- 3D printing cheap probes to test cement block strength (like this one)
- 3D printing demonstration model walls/miniature rebar systems (lego-styli)
- 3D printing long lintels with neat interlocks into block or adobe
- 3D printing bespoke gusset plates and straps for any old type of homemade truss