queen storage bed help

Hi I was wondering if anyone whos built this "queen size storage bed"
http://ana-white.com/2009/11/queen-sized-storage-bed?page=1#comment-433…

could help me out I really would like to add 5" to the height of this bed, anyone know how I could do this and still keep it sturdy ?

{ when I print the plans the # are so small I can't read it, is it just me ? }

thanks
Natasha