A mailman in distress

Mr. Zdzisław is simply a mailman. He and his 5 relatives occupy a municipal place in Warsaw. The place is rather large in pre-war construction. 4 rooms with balcony. The rent's not low, though it's a municipal place. The aunt and her children leave the work to pay rent to him, like to drink alcohol alternatively of work. The law states that rent must be paid jointly and severally...