I built bunkbeds for my sons out of 2x4s. Don't really need a plan. Just get the size of the mattresses you wil use
Here are a number of designs for DIY bunk beds. Scroll past the images in the first link to locate the bunk bed plans using 2x6 boards.
http://ana-white.com/2012/03/plans/side-...
http://ana-white.com/2010/09/classic-bun...
http://ana-white.com/2010/01/plans-how-t...
http://ana-white.com/2011/01/plans/twin-...
http://ana-white.com/2013/06/plans/tripl...
just looking for a simple plan for a bunk bed made with 2x6 lumber, just simple and plain
