<p>You can apply for UIUC resdence halls only after you have accepted offer to admit. </p>
<p>You can apply for private certified housing before accepting offer to admit. In fact order of receipt of applications for each PCH is the order in which they offer residency in them and thus later applications can sometimes result in no offers. Each PCH has its own application and deposit rules and you need to check each carefully to see what the penalty is for later withdrawing your application.</p>