If you're switching mortgage providers without increasing your loan amount you are exempt from the rules no matter what your existing bank have you. But as Brendan says the bank doesn't have to take you.
If you're looking to increase your mortgage, say to cover renovation or other factors, you would be subject to the mortgage rules and depending on personal circumstances may require an exemption.
For example, if you borrowed € 1million and have €999k outstanding you are exempt from the rules if you are looking for €999k (or less) but fall under the rules if you are looking for more than the outstanding amount (€999k).