23 Lines - a (former) 40k Blog, in his terrific post about getting started in Infinity, put up a link to Toposolitario, where you can download free printable habitation blocks for sci fi gaming. It's actually pretty rad. When you first go to the site, you are likely to do exactly what I did, see that the site is not in English and despair. Never fear, notice that on the right side of the page, the whole site is repeated in English.
There are six varieties of hab cube on the page that are available for free printing, and honestly it looks to be a genius idea. I am going totally make a whole Hab Block and start rocking. Seems like this came with just PERFECT timing for my vacation.