The perfect storm of economic and regulatory conditions is shifting gears for underwriting standards in the mortgage lending environment.

While mortgage rates tick back up, some economists caution the market to not forget that rates were roughly the same, at 4.5%, two years ago.

Additionally, housing affordability is at an all-time high, while existing home sales posted solid numbers.

The biggest road bump in the sector that’s impacting credit availability is refinancing, explained Equifax chief economist Amy Crews Cutts.

"There’s options out there, so you have flexibility," Crews Cutts said.

She added, "A house is not like a gallon of gasoline, it’s not at a fixed price. From a demand side it’s more of a psychological effect than a real effect, and even if we have a bump earlier on it’s not a deal killer for someone to buy a house."

Although the housing data supports a full recovery and is enticing buyers into the sector, the market is dealing with a tighter underwriting landscape.

The repurchase risk that is currently on lenders from both government-sponsored enterprises has caused them to step up quality assurance. Consequently, mortgage insurers have set their quality assurance standards high, fearing any type of backlash, Crews Cutts explained.

While it’s too soon to tell what impact the qualified mortgage rule and qualified residential mortgage standards will have on mortgage lending, some hare hopeful that banks will be more comfortable lending if transparency and rules are made clearer, stated Trulia chief economist Jed Kolko.

"Also, rising mortgage rates could have the unexpected effect of opening up credit, because refinancings have plummeted as rates rise, some banks might increase their home-purchase lending," Kolko stated.

He continued, "For both reasons, therefore, we could see mortgage credit expand next year."

While the Equifax chief economist doesn’t have a position on the forthcoming QM and QRM standards, the act of drawing a line the lending environment sand is going to provide more incentive for the market to remain conservative on how much underwriting is completed.

"From a holistic standpoint, if you have very high income, excellent credit and made a significant down payment, I would feel more confident in giving you a loan at 45% debt-to-income ratio," Crews Cutts argued.

She added, "Now if you’re a first time homebuyer, fresh out of college and you’re income isn’t terribly high, I’m not sure I want to go to 43%, but I’ll bump it down to 33% because of the large penalties that will happen if I cross that line."

While it’s inevitable that regulators have to implement a rule, the near-term impact on lending for families much closer to a line where affordability and income matter will be tested.

Overall, while the market admires the intention of the rule, many wonder if the access to credit currently, and in the future, will be able to meet fair-lending practices.