Home loan and continuing residence permit

EDIT: Thank you all for the discussion and by all means continue commenting. We received a message from OP today that the residence permit doesn't matter to them, and we have received a loan offer. This is a great relief.

Today I had a loan application meeting with Säästöpankki, where it came to light that I would be ineligible for a loan on the basis of my residence permit (Family ties, type A, valid until May 2028).

I was informed that Säästöpankki would not underwrite a loan to an individual whose residence permit did not last the loan's duration (in practice requiring a permanent permit). That the loan would be taken out with my Finnish spouse did not matter, all parties to the loan would require permanent residency.

This was somewhat deflating, and upon asking Danske and Nordea the response was similar, although the Nordea representative remained coy regarding the effect of a Finnish cosigner (apply and find out, they said).

I am not eligible for a permanent permit for 4 years, but our little family would be interested in purchasing a house before then. Is anyone here aware of, or has firsthand knowledge of, a Finnish lending institution which either does not require a permanent permit or whose requirement can be mitigated?

I am in the process of asking S-pankki and OP, but would also like to ask here. As far as I know there is no way to speed up the permanent permit timeline, so if it is simply a fact that foreigners in Finland must wait four years to buy a house, I was blissfully ignorant of it.

I would hate to have to resort to unorthodox financial methods to achieve home ownership.