<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Earth_structure" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Earth_structure</a><p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Cob_(material)#Modern_cob_buildings" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Cob_(material)#Modern_cob_buil...</a><p><a href="http:&#x2F;&#x2F;www.sotaconstruction.com&#x2F;project_details.asp?id=42" rel="nofollow">http:&#x2F;&#x2F;www.sotaconstruction.com&#x2F;project_details.asp?id=42</a><p>Even mud hut technology has advanced well beyond huts.  The &quot;greenest building in Pennsylvania&quot; is a glorified mud hut with underfloor heating.  It contains more than just one century of advancements over the most basic earthen construction.<p>And perhaps you haven&#x27;t seen the sort of houses that people lived in, even as late as the 1930s, in some parts of the country.  Let&#x27;s just say there is a good reason why pre-manufactured homes are popular in certain places.  Upstate New York may not exactly be a representative sample for the housing conditions in 1915.