Grounding? O.o

http://www.trendir.com/house-design/underground-house-by-polish-architecture-firm.html

http://www.spacemakerpress.com/lfjune98/lfpage05.htm

http://blog.civilengineergroup.com/underground-homes-introduction.html

http://bsa-y1-group3.blogspot.com/

http://nexgadget.com/2010/10/13/the-skyscraper-that-grows-underground-architecture/

http://www.architecture-view.com/2010/05/24/mountain-hotel-basement-efficient-and-beautiful/