Conventional loans are secured by government sponsored entities or GSEs such as Fannie Mae and Freddie Mac. Conventional loans can be made to purchase or refinance homes with first and second mortgages on single family to four family homes.

2008 Single-Family Mortgage Loan Limits
Single-Family Mortgage Loan Limits effective January 1, 2008:

First mortgages

One-family loans: $417,000
Two-family loans: $533,850
Three-family loans: $645,300
Four-family loans: $801,950
Note: One- to four- family mortgages in Alaska, Hawaii, Guam, and the U.S. Virgin Islands are 50 percent higher than the limits for the rest of the country.

Second mortgages

$208,500
In Alaska, Hawaii, Guam, and the U.S. Virgin Islands: $312,750
Last Revised: November 27, 2007

For further information on Loan Limits you can go to Fannie Mae:Fannie Mae Loan Limits