In the case of sublease, the subtenant falls under the security of tenure of the subleasing tenant who is leaving the room (temporarily), not of the house owner (landlord). If the main rental agreement allows for sublease, or if it doesn’t address the matter, subleasing should not be a problem. If the main rental agreement specifically states that subleasing is not allowed, subleasing is strictly prohibited. Usually, the subtenant leaves whenever the subleasing tenant returns.