The Seattle Humane Society is in the early stages of designing an expanded, three-story facility in Bellevue to replace its outdated campus on Eastgate Way.

“We’re really at capacity for what we can do for the animals,” said David Loewe, chief executive officer for the Seattle Humane Society.

The humane society has been in existence for 117 years, opening its Bellevue facility in the 1970s. Replacing its Eastside shelter has been considered for the past 14 years, but the society board has only been seriously planning the new facility for the past four years.

“We want to do it once; we want to do it right and really get us set up for the next 50-plus years,” Loewe said.

Adopting out about 6,000 dogs and cats each year, the Seattle Humane Society boasts a 97-percent save rate. Its Bellevue facility provides comprehensive care for its shelter animals, but its medical center is too small to quickly address the growing demand for service across a three-county area. It also takes in more than 3,000 animals each year from shelters and animal groups taking advantage of SHS’s Life-Saver Rescue Program.”It really does become a kind of choke point,” Loewe said of admissions to the medical center.

The humane society proposes to raze its main building, keeping its separate kennels and adoption center open while the new 54,000-square-foot facility is constructed. Once complete, the kennels and adoption center would be moved into the new facility.

By doubling its square footage, the humane society expects to increase animal admissions capacity by 35 percent. SHS has a goal of adopting out 10,000 animals per year once the new facility is constructed. The new facility will also allow the humane society to add to the number of Washington State University veterinarian students that can work elective rotations there, Loewe said.

Expansion of the Eastside facility will also allow the society to add more education programs to its services.

The humane society is in a soft fundraising phase as it awaits environmental clearance from the city to begin looking at designs for the facility. Loewe said an architecture team is working with the humane society’s board to gather ideas.