FOR many parents of college-bound children, the runaway growth in housing values over the last decade has prompted an anxiety-inducing question: Can colleges require parents to use their home equity to pay for school?

The answer is yes, at least for some colleges. But in instances when it does happen, colleges will expect parents to extract at most 6 percent annually, according to financial aid counselors and college finance specialists. Whether parents should take that route, though, and how they should manage their mortgage and college planning overall, depends on a number of factors, these specialists said.

Only a small minority of the nation's 3,000 colleges and universities even ask about home equity when considering financial aid, said Cindy Bailey, the executive director of the education finance services division of the College Board, a nonprofit organization that, among other things, helps universities make financial-aid assessments.

Ms. Bailey said about 400 colleges,   typically the more expensive, well-endowed, competitive colleges, will require parents to estimate the amount of equity available in their homes. They give out a lot of money in financial aid, so they want to know the whole story of the family's finances,  she said.

Public colleges and universities, by contrast, expect students to rely on state initiatives like New York's Tuition Assistance Program and federal Pell Grants to help meet their tuition needs.

States generally do not ask about home equity when making those decisions, and the federal government stopped doing so during the Clinton administration.

Heather McDonnell, the director of financial aid at Sarah Lawrence College in Bronxville, N.Y., said that like her counterparts at other institutions, she looks to other factors to determine if a student's parents should take out a home-equity loan to help pay for tuition. If you're sitting on home equity of $500,000, but you could only afford a second mortgage of $100,000, that's what we'll be sensitive to,  Ms. McDonnell said.

In addition, Ms. McDonnell said that depending on how large the institution is, parents may be able to discuss their situation with financial aid counselors if, for instance, they were planning on taking out a second mortgage to fix a leaky roof or pay for some other pressing need. I've had someone mail me a picture of the house to show how much work it needed,  she said.

Some college planning specialists caution against using home equity to pay for tuition. Carl Buck, the vice president for college funding solutions at Peterson's publishing company in Lawrenceville, N.J., and the author of Get a Jump! The Student Aid Answer Book  (2005), said: I consider second mortgages a loan of last resort. If you lose your job, you lose your home.

But Rick Darvis, a founder of the National Institute of Certified College Planners in Syracuse, said that home-equity loans have tax advantages other loans lack. While mortgage interest is fully tax deductible, Mr. Darvis said, popular government loans like Federal Plus are more limited, and not just because interest rates for such loans are about 8 percent.

Families who take out Plus loans can deduct only $2,500 in interest annually, and only if the borrower earns less than $135,000 a year. In addition, Mr. Darvis said, when parents take equity out of their homes, they decrease their overall net worth, which can increase the amount of financial aid that some colleges give in subsequent years.

One advantage of Plus loans is that if the borrower dies or becomes disabled, the repayment obligation ends. But if you go with home equity, you could take your tax and interest-rate savings and go buy some term life insurance,  Mr. Darvis said. That way if you die, your loan is covered.