Rent increase under new landlord
We signed a rental contract in 2015. The rent has never been indexed, and we didn't pay any communal charges. The landlords have now sold the apartment and the new owner wants to index the rent and impose communal charges. As a result, the rent/charges are increasing by 35% with one week's notice before the first payment is due to the new owner. The timing seems unreasonable. Is there a minimum notice period a landlord has to adhere to when increasing rent? Grateful for any tips of where to find info on this.