All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
If such facilities and improvements in the house are real benefits that are worth extra money, then it is permissible for you to ask the landlord to provide them for the extra rent money mentioned in the question and it is permissible for you to enjoy them.
However, if they are not worth the extra rent money, you are not allowed to pay him that extra amount because this is considered as betraying the trust and helping in consuming people's money unjustly. Allaah The Almighty Says (what means): {O you who have believed, do not consume one another's wealth unjustly.}[Quran 4:29]