Pack up and be out no later than the date the lease expires.If you didn't sign tne tenewal, you will not be a legal tenant as of the first day of the new lease term, and therefore have no legal right to be on the premises.It's up to the landlord whether he will allow your flate-mate to lease by himself. You may both have to leave unless an acceptable (to the landlord) replacement is found and signs a lease in time.You may be entitled to half of any refundable deposits, unless you haven't given the landlord proper notice that you're leaving. Check the existing lease for those terms.