A balsa wood model under a pristine glass case in a Hoag Hospital Irvine office is the first step of a vision for a major expansion of the medical center on Sand Canyon Avenue, which will add, among other services, two specialty hospitals focused on women’s health, digestive illnesses and cancer.

When that model is brought to life, Hoag will have poured an eye-popping $1 billion into the expansion and added between 1,000 to 1,500 staff members, many of whom have specialized jobs and training.

The Irvine location will be called the Sun Family Campus in recognition of a $50 million gift to Hoag by philanthropists Diana and David Sun earlier this year.

Six buildings will add 155 more hospital beds, eight operating rooms and 120,000 square feet of offices and other “support space,” said Hoag CEO Robert Braithwaite. The specialty hospitals will have inpatient and outpatient facilities, operating rooms will be housed in a new building, and pharmacy and laboratories will be in another.