A real estate expert believes the new mortgage rules that went into effect Monday will hit Alberta's market the hardest.

The changes are meant to make it tougher for buyers to qualify if they put less than 20 per cent down.

Prior to today, an Alberta family with a household income of $80,000 and a minimum down payment of five per cent would likely have qualified for a $400,000 home but now they will be approved for a $320,000 home.

Mortgage specialist Peter Kinch says under the new rules, affected buyers have about 20 percent less purchasing power which will put a downward pressure on the Canadian real estate market but he says the impact will be even greater in Alberta, where the slumping economy is already hurting house sales and prices.

"In a real estate market that's struggling to recover already, it could have a very negative impact on that market," Kinch said.

Natalie Whitney and her young family say that's what they're banking on so they've just decided to put their house hunting on hold.

"It could be advantageous for us to wait and just see what happens to the market in six months," she said.

The Canada Mortgage and Housing Corp. issued its first ever "red" warning on Monday, referring to real estate affordability issues spreading beyond Vancouver and Toronto.

"These factors will be reflected in our forthcoming Housing Market Assessment on Oct. 26. They will cause us to issue our first "red" warning for the Canadian housing market as a whole," CEO Evan Siddall wrote in a Globe and Mail column.

Kinch says for buyers who can't wait, they'll either need to come up with a bigger down payment or lower their expectations about what they can afford.