There is in fact a cheat that can be entered to make your own Dorm and YES it does work
Here is a post from another forum i visit This again DOES work
also You can download dorms premade as well
Build a dorm on a University lot. Then type in Ctrl shift and C at the same time. At the top of the screen you should get a small white bar. In there type changeLotZoning dorm
then exit the lot when you re-enter it should be a dorm. Make sure you remember to but a stove( the new ones) in your kitchen so the cook will come and prepare all the food.
hope this helps
Some places to download some nices ones include
these below are Hack free so are safe and will not add anything to your game that may possibly cause issues
http://lsre.jillyann.com/
http://thesims2.ea.com/exchange/lot_detail.php?asset_id=123806
http://thesims2.ea.com/exchange/lot_detail.php?asset_id=122894
there are also some at TSR and MTS But Please be cautious and check for hacks and such so that none slip in and mess up your game
April