you must have a min savings of 2900 (to cover legal fees) and also must have 3 to 5% of the purchasing price to use as a deposit (some local authorities will give you 95% mortgage, others will give you 97%). You must also have proof of regular savings for the past 3 to 6 months for at least €600 to €700 per month, although they will consider rent as a saving also (this is to prove that you can pay back a mortgage). If you have savings, you can put these down as a deposit to reduce your mortgage. I don’t know if there is a maximum amount of savings that you can use.
I hope this answers your questions
John.