In most places in the U.S., owning a home has gotten even cheaper than renting one.

A report released Wednesday from Trulia – which took into account all costs associated with buying or renting over a seven-year period – found that buying is 38 percent cheaper than renting in all of the 100 largest metropolitan areas.

The buying-over-renting advantage ranges from 17 percent cheaper in Honolulu to 63 percent cheaper in Detroit. The prices of renting and buying are closer in California and New York, while the gap is widest in the Midwest and South.

Jed Kolko, Trulia’s chief economist, says that the reason for the cost advantage is twofold.

“Mortgage rates have come back down in the past year and rents have risen a little more than prices have,” Kolko says. “Those things together have increased the gap between the cost of buying and the cost of renting. Over the past year, buying has become even more favorable compared with renting.”

Over the past year, the 30-year, fixed-rate mortgage rate has fallen to 4.3 percent from 4.8 percent.Rents rose 6.5 percent over the past year, while single-family home prices, excluding foreclosures, rose 6.4 percent, Trulia data show.

“The cost of buying instead of renting depends on the type of loan you have,” Kolko says.

For the study, Kolko assumed that buyers make a 20 percent down payment, get a 30-year, fixed-rate mortgage at a 4.3 percent rate, itemize their federal tax deductions and are in the 25 percent tax bracket. He also looked at the benefit of different types of payment methods, including all-cash or a 3.5 percent down payment with a Federal Housing Administration loan – the latter which could be preferable for first-time buyers. 

Other financing options lead to an even bigger cost advantage. For example, the 15-year loan ends up costing least versus renting over seven years since the equity build-up time is shortened and more of the mortgage payment goes to principal rather than interest.

Mortgage rates would have to rise significantly before renting became more cost-effective than buying. They’d have to rise to 8.9 percent in Austin, 15.2 percent in New Orleans and 29.1 percent in Detroit, for example, to make buying a better option, the report showed.