Gst on common sharing expense

We are a finance company took premises for lease. Now the landlord who is the owner of that particular floor in the building is raising invoice for rent with GST so clear in that part. But in addition to that for common lift maintenance, electricity charges and security guard expenses they are raising invoice with out GST stating that they are just passing on the expense that were levied to them by the building associaton who is not registered under GST with out any mark up and have given all the workings to establish concerrrence on their part that they did not include any mark up. Is that pratise of land lord correct? GST need not be levied/to be levied? Same time for the common sharing expenses portion whethte TDS can be deducted ? Please help me with relevant provisions on both GST and TDS