The new 3,700-acre extension of Sienna Plantation in Missouri City—Sienna South—remains on track to have its first cluster of homes ready to sell in spring 2015.

Alvin San Miguel, vice president and general manager at Johnson Development Corp., said the final months of 2014 were dedicated to site development and infrastructure construction. He said builders would have access to the lots by the end of January.

Toll Brothers acquired the 3,700-acre tract from Hillwood Communities in 2013, and hired Johnson Development to develop Sienna South. Toll Brothers is among the many builders with contracted lots in Sienna South. Others include Darling Homes, Westin Homes, Highland Homes and Ryland Homes.

"A lot of those builders are builders we already have in Sienna Plantation, and some of them will be new builders," San Miguel said. "We have about 500 lots that are going to hit the ground by the end of the first quarter."

Sienna South is expected to be complete within the next 10 to 12 years, and will have approximately 6,500 homes, he said.

The Sienna South expansion includes 140 acres of commercial property that is being marketed for sale. Only 40 to 45 acres have direct access to the neighborhood while the remaining acreage is located off FM 521.

"We still have a lot of commercial retail [property] near Sienna Parkway," San Miguel said. "Some things could happen here in the next few years, but as of right now, [the retail acreage] has just been on the market this year."

As Fort Bend ISD nears finalizing the district's new feeder patterns and attendance boundaries, Johnson Development has continued to monitor projected growth trends in Sienna South to present to the district.

"We've met with representatives of Fort Bend ISD and showed them the long-range plans and the more immediate phasing plans of the number of lots that are going to the ground," San Miguel said.