Even if the 0.7%
Difference between 100% and 110% can already be 0.5% or more (based on the total loan amount).
The equity must be proven at the conclusion of the financing: or then the loan-to-value ratio is determined.
What you then save, let's say during the construction period, is also good; but does not change the financing
Most banks did not offer us 110%, and from 100% it became significantly cheaper. Due to a relatively high income and high repayment rate, I received similar terms that are often mentioned here for 80%.
Saving up equity would not have made sense for us, and I generally consider it not sensible at all, at least for high incomes, which I would rather not count the OP among at the moment.