Today, selling a house may take longer in many markets, but that hasn’t completely discouraged certain homeowners from moving to a larger house or apartment to accommodate their family in greater style or simply fulfill a dream.

Homes in fact, have gotten bigger – even if not by much. From 2004 to 2006, the size of the typical purchased home increased by about 100 square feet, to 1,840 square feet, according to the 2007 Profile of Buyers’ Home Feature Preferences, recently released by the National Association of Realtors.

But before you follow this trend, understand all the pros and cons of taking on more square footage and increasing your costs. You don’t want to assume so much extra space – and costs – that you’re not sleeping as well in your new master bedroom. Ask yourself the following questions:

Why do you need more space?

Analyze and list your reasons. If it’s a temporary infatuation, your interest may fade, or you may be able to rearrange space in your existing home to fulfill the need. But if it relates more to day-to-day living, such as an extra bedroom or bathroom if you’re feeling squeezed and can’t remodel or add on, you might be wise to upgrade. The NAR’s Profile of Preferences put garages with two or more spaces at the top of many recent buyers’ wish lists, along with walk-in closets in the master bedrooms.

Besides gaining larger square footage, you also may want to move up because of the associated advantages that can come with a larger, nicer home, such as a more attractive neighborhood, better school district, nicer park and community facilities and maybe more quality shops and restaurants, says Randy Duncan of Realty Executives, Tempe, Ariz. A more upscale location also may result in a quicker sell, says Lisa L. Williams, principal broker with Senate Realty Corp., Washington, D.C. That, of course, will depend on the health of the market in the area.

Did you calculate all related costs?

Besides a higher price and mortgage payment, you’re apt to incur numerous other expenses: taxes, utilities, maintenance costs and new-home purchases, such as furniture. In addition to the greater costs, keeping up with the Joneses may soon mean more than just having a similar-sized house. You may feel compelled to buy fancier cars, add a deck, upgrade furnishings or appliances. And even if you aren’t competing with your neighbors, you may find that your old, smaller-scaled furnishings don’t fit as well in your new rooms, which probably are larger.

All the extra expenses may make it tougher to enjoy the discretionary purchases you have typically enjoyed, such as vacations and meals out. “You don’t want to be house poor and not enjoy the lifestyle you had,” says Robert Harrington, founder and chairman of OptHome, a brokerage firm in Southborough, Mass.

Rob Bennett, author of “Passion Saving: The Path to Plentiful Free Time and Soul-Satisfying Work (Freedom Store, 2005), says, “Expensive housing is the single biggest reason why most middle-class workers view early financial freedom as beyond their reach. It’s possible. But those who do it examine the trade-offs between the fun that spending buys and the freedom that saving ‘buys.’”

Bennett adds, “Earnings have skyrocketed, but instead of saving more, people are spending more as affirmation of their success. The housing industry is a huge beneficiary, as are storage companies. People are paying money to store all the belongings they can’t fit into their homes.”

On the upside, however, is the possibility that your larger home may have been better maintained, or newer and have much more efficient heating and air conditioning and better insulation, says Williams. Depending on the health of your market, you may be able to take advantage of a smart purchase since bigger homes in some areas have seen bigger price drops, adds Harrington. Duncan agrees: “Everything is on sale, especially in new construction,” he says.

Can you afford the bigger house according to the old rules?

Before it became possible to put little or no money down, many homeowners would never have dreamed of buying a house if they couldn’t make the 20-percent down payment that eliminates private mortgage insurance. And their lenders wouldn’t have let them. These homeowners also heeded the adage that their total housing costs should add up to no more than 25 percent of their gross income. Financial guru Manisha Thakor, a Harvard MBA graduate who co-wrote “On My Own Two Feet with Sharon Kedar (Adams Media, 2007) suggests going back to those guidelines, whether you buy small or large. “Many people have bought more house than they could afford. If they spend a lot of time in their home and can afford it, that’s fine, but you shouldn’t let a house hold you hostage,” Thakor says.

Have you considered your timetable?

Even if you feel you can handle the bigger house price and related expenses, it may make sense only if you’re going to stay put for several years, five at a minimum. Buying a new house and selling a home involve closing costs. And if the size of the household decreases, you may end up wanting to downsize a few years, says Harrington.