An order to demolish the building by Feb. 14 has been moved to April 11, said Trang Huynh, Rancho Cucamonga's building inspector.
The extension came after a request this week by the Cucamonga Valley Water District, which owns the property.
After years of concern over the fate of the building, the district had come up with a plan to demolish it. It planned to use some of the original brickwork for a memorial to honor the Chinese laborers who lived in or near the building in the early 20th Century.
After learning of the demolition plan shortly before the new year, regional Chinese heritage group members rallied to convince local water district officials to delay demolition plans. The groups plan to form a China House preservation committee with the Historical Preservation Association of Rancho Cucamonga to come up with a plan to save the building from demolition.
Jo Lynne Russo-Pereyra, assistant general manager of the water district, said the water district is willing to give the groups more time to come back with some type of plan for the building.
Eugene Moy, vice president of the Chinese Historical Society of Southern California who will co-chair the new committee, said the first step will be to stabilize the building.
"If we can make progress, I'm hoping the city will be willing to provide further extensions," Moy said.
"We are going to work diligently and in good faith to come up with a plan and I'm hoping that the city would recognize that and would allow the process to be extended so that good work can be accomplished."