You will probably get a mortgage of €180,000-€184,000 if you save €16,000-€20,000 yourself. You will not get a 100% mortgage nevermind the 107.5% mortgage you are proposing.
Banks have no interest in giving you the extra €15,000 at a low rate of interest when they can lend you the €15,000 separately at a rate of 10% apr over 10 years. During the boom you might have got the extra €15,000 if it was invested in adding value to your house.
What you may be thinking of is consolidation loans that were secured on your house. Some one might have had a house worth €300,000... a mortgage of €150,000, and credit card debt of €25,000, so banks would offer a loan of €175,000 paid over a long term at a low rate of interest. This is because the total LTV ratio would be 175k/300k = <60%. You were essentially "releasing equity" because the value of your house was much higher than your debt.
This will not be true in your case.