A Northern California homebuilder announced plans to build 120 single-family houses across two new neighborhoods in Rancho Mission Viejo.

The new houses in Orange County are part of San Francisco Bay Area-based Trumark Homes’ larger play to add new housing in Southern California, with 450 residences planned for the region.

Trumark plans to build 56 single-family houses at Lotus at Rienda at Rancho Mission Viejo. The second development calls for 64 single-family houses at Rancho Mission Viejo’s Sapphire at Rienda.

The houses at Rienda would range from 2,769 square feet to 3,129 square feet, with three to five bedrooms and three to four-and-a-half bathrooms, plus a two-car garage.

Sapphire’s houses would range in size from 2,461 square feet to 2,823 square feet, with one to five bedrooms, one to four bathrooms, and a two-car garage.

Prices for both developments would start at about $1.6 million. One of the three floor plans offered at Lotus has already sold out.

Sapphire and Lotus are two of three neighborhoods to be built at Rancho Mission Viejo this summer.

Shea Homes unveiled its Arrowleaf neighborhood, with five-bedroom houses starting in the high $1 million range.

All three communities officially debuted on June 22.

Trumark also announced plans to open new houses for sale in Chino, Chino Hills, Covina, Escondido, Loma Linda and Redlands.

Richard Douglass, Southern California division president of Trumark Homes, said Orange County is a unique place to build homes, as there are only three master-planned developers in the region.

Douglass told the Business Journal that Rancho Mission Viejo is home to “the best real estate” in Orange County and is emerging as the next great development.

“We are committed to creating communities across Southern California that meet and exceed the needs of local homebuyers, while increasing the overall inventory to support the high demand,” Douglass said separately in a statement. “These exceptional new communities are already experiencing strong levels of interest from homebuyers looking to enter the market, as well as from existing homeowners who want to move up or down this year.”

Trumark has had a significant number of key employees working at its OC offices.