Q: We are interested in buying a home that is under construction in a development where sales have been very strong. The contract the developer gave us says that the company would get to keep 100 percent of the net profit if we sell the home within one year of moving in. We don’t plan on moving that soon, but we’d like to keep any profit if our plans change. Is the developer’s demand common? More importantly, is it legal?

A: It’s fairly common for builders, especially those with hot-selling projects, to require prospective buyers to agree to give up some or all of their profit if they re-sell the home in, say, six months or a year. And though it might not seem fair to buyers, the practice is usually perfectly legal too.

Home builders deny that such profit-sharing requirements are motivated by their own greed: Instead, the rules discourage short-term real estate speculators from snapping up houses or condos while they’re still under construction in the hope of soon “flipping” them for a huge profit when the final phase or two begins to sell out.

Eliminating speculators helps keep prices from skyrocketing during construction, builders say, which in turn makes the homes more affordable for buyers who plan on living in the development.

It’s also worth noting that lenders charge lower rates to buyers in projects where most residents are owner/occupants rather than owner/investors, in part because people who live in their own houses generally take better care of their property. By including a profit-sharing clause in their new-home contracts, builders can demonstrate to lenders that the development won’t be dominated by speculators or renters, which helps long-term buyers qualify for the best financing packages.

That said, you’re under no legal obligation to automatically accept the profit-sharing clause contained in the contract that your new-home builder has offered: By crossing out the paragraph and initialing it, you’d be making a counteroffer that the developer could then either accept or reject.

If the builder rejects the counteroffer but you want the house, you could try a different tactic, such as asking that the profit agreement be shortened to six months, or that you’d have to share only 50 percent or 75 percent of the gain if you re-sell before the one-year requirement.