Most builders will ask you to put your license in inactive status. This is to avoid any conflict of interest. You will find also that most builders prefer to hire a housewife with no high school diploma than a seasoned Realtor with a college degree. This is simply because of liability reasons, as a Realtor you know too much and they prefer to have someone that they can "mold" according to the company's culture.
One of the biggest downside is that you have to work on weekends. If your spouse is on the same schedule that's great otherwise it can become a strain. The money can be very good with the right builder and the right community.