Aspiring homeowners are locking up their lives - including possibly cutting health costs - to try increase their chances of getting loans approved by banks under stricter rules.

The Council of Financial Regulators is investigating whether changes to the Credit Contracts and Consumer Finance Act, which came into effect in December, have been implemented as intended.

Amelia* and her husband, who only became aware of the changes to lending rules shortly before they kicked in, were picking apart their spending in hopes of being able to buy a home this year.

They were worried about what costs could trip them up.

For Amelia, that included concern about her ability to regularly see a therapist for her mental health - something she just got off the long waitlist for.

"The fact that I, as a person, have to think 'should I get therapy or should I get a house?', I think that's really problematic."

There is an overarching umbrella of confusion: Amelia did not think the CCCFA rules were clear or easy to understand as a consumer.

She says it feels like "you can't have any extraneous joy in your life that is surplus to need from the bank's eyes so you should just live this life of: you work, you go to the grocery store, you make your food, you never go out to eat, you don't see your friends and you just sit in your house until you can buy a house".

Jared* has similar feelings.

He and his wife purchased a new house off the plans about a year ago and were pre-approved a home loan, which has since been renewed every few months.

He says they had to "redo the whole process" once the rules changed, "and then [the bank] gave us quite a vague email that said 'oh yeah, we'll do it again just before you settle but it should be okay'".

Jared says their house is now "almost finished", but the email "didn't give us too much reassurance".

"How do we know we have the firm-word from the bank that they're actually going to give us the mortgage?"

He thinks the new rules are stormy waters for consumers, especially because he has previously had a mortgage that his bank had no issues with.

Jared says that "was the scary thing" because he is now "staring down the barrel of having $600,000-$700,000 mortgage and not knowing what the bank is going to say at the end".

Financial Advice New Zealand chief executive Katrina Shanks says the CCCFA rules do not allow banks discretion and do not align with real life.

She doesn't think having "clean expenditure" for three months protected vulnerable consumers like the changes intended.

"No one thought it was designed to reach so far into someone's personal life and determine that because you have a committed expenditure, for now, to go see a therapist, or to go and see a doctor, that that would hold you back from being able to obtain credit."

Shanks says banks need more discretion, otherwise things are going to get "very, very stressful" for the consumer - particularly those building a home, like Jared.

RNZ approached all of New Zealand's major banks for comment.

Westpac suggested RNZ speak to the Bankers Association, and ASB and BNZ did not respond by deadline.

Kiwibank and ANZ both recognised things are more intense than they used to be, but says they are just following the rules.

*Names in this story were changed to protect the identities of those trying to secure bank lending.

-RNZ/Jake McKee.