Very good question. Many seniors graduating from school already have a mortgage on their hands. I've spoken to several people who have student loans totaling over $150,000. Unless you've landed that high-powered, high-paying job, chances are a mortgage company is not going to fork over money to you so you can owe even more. Would you loan money to someone already in debt for $150,000?
Your best first step would be to start paying down on that student loan and start saving for a down payment. This will prove to a future mortgage company that you're worthy of handling their money. This can only happen if you have a job that is paying enough so that you can pay off your loans and save for the down payment. If you're independently wealthy then you probably won't have the student loan to begin with and you don't need the mortgage.
This brings me to my main point: your job. Obviously, if you don't have a job, you won't get a mortgage, so you won't be buying the house. While this may make you think, "Duh,?" it wasn't too long ago that lenders were letting people borrow money for a home as long as they could fog a mirror.
So, you're under 30, have a job, have a $150,000 student loan and want to buy a house. Great; the lender sees that you've been paying down your student loan and you have between 5% and 10% of the sales price of the home saved up. The lender lends you the money and you buy the home of your dreams. Then...you lose your job. You start looking for another. You have to pay your mortgage while you're looking with no income, but you'll be okay for a couple of months.
You get lucky (not many people do in this job market); however, the job is in Toledo, Ohio. Oh boy, I've always wanted to live in Toledo! But what if you lived in Seattle? It used to be you could sell your home in a couple of months if you had to. Not in this market; some homes stay on the market for several months. You think, well, I can move to Toledo for that really cool job, rent an apartment (no one is going to lend you money for a new home when you have student debt an an existing mortgage on a home you can't sell.) But wait, although the job in Toledo pays well, it doesn't pay that well. Can you afford to make a mortgage payment and a rent payment until your Seattle home sells? Probably not. The point is, buying a home in this market may make you inflexible; you're going to be saddled with staying in Seattle for your employment.
Owning a home is not the same as it was for your parents. You buy a house, work in the same city for 30 years, the value of your house increases, and you sell it (fairly quickly) and downsize when the kids are grown and hopefully gone. This doesn't happen any more in our current economy; you could be chained to your house for a long time.