Rather big difference in lending (big 4)

I purchased a OTP property in qld that is under 50m2(1 Bedder not a serviced apartment) that i have asked about before in a few other threads.Even though the completion is +1.5years away and i know regulations will prob change before then i thought i would go see the big 4 and see what they will do for me and was rather taken back by the rather large difference between them.

ANZ -will lend 70% above 40m2 wont inc Alfresco
CBA -will lend 80% above 18m2 will even inc my enclosed Alfresco providing you can lock it which puts it over 50m2 which means i can even get 90% with LMI.
NAB-will lend 80% for just under 50m2 postcode dependent.Same as CBA though will inc Alfresco making it possible to lend 95% with LMI
Westpac- wont even lend at all under 50m2 wont inc Alfresco

Has it always been the case were there is such a massive difference between the big 4 or only recently??Knew there would be a little difference between them but 95% with LMI to not lending at all is huge!!
Well i am learning the hard way,i still think my purchase will work out fine for me it tick's all the right boxes.But i can tell you right now i will never ever buy under 50m2 again that's for sure.I should have known better 2bh.
funny thing is Westpac would have thousands of them on the books they dont know about becasue of their old no valuation policy!
I stripped out a 32m2 unit 2yrs ago at Kangaroo Point for a guy.
He had trouble getting finance because of the size and used his existing house as security. Paid $170k on 5th floor with great views over the storey bridge, it was just up the road from the pub. He spent 30k renoing and a year later (which is 1 yr back now) had it valued at 300k.
He bought another one and I just gutted it a few weeks ago which is on the same site but this building runs adjacent, which is along the Brisbane river. He paid 300k for the same size but its view is the whole city:eek:
I can't see him going wrong with this one either as he can't be built out and that view is just amazing.