The nonprofit organization Public Architecture has reached a milestone in signing up 300 firms to participate in its 1% Program, an initiative through which architects pledge a minimum of 1 percent of their billable hours annually to pro bono service.

This represents a commitment of more than 90,000 hours in design services worth an estimated $9 million annually.

“This represents a growth of 100 percent since the re-launch of The 1% Web site last October,” said Public Architecture founder John Peterson. “The rapid growth is fueled in part by a new matching system through which architecture firms and nonprofits can seek out partnerships online.”

Starting last fall, nonprofits were invited to register their needs with the program to find architecture firms interested in partnering on pro bono projects. More than 100 nonprofits across the country have signed up.

“As architects whose projects are inherently public, we know how important design is for enabling people to interact and work with each other,” said Peter Kuttner, FAIA, president of Cambridge Seven Associates, the 300th architecture firm to pledge commitment to the program.

The 1% program was launched by Public Architecture on March 31, 2005, with the support of a grant from the National Endowment for the Arts. Along with renewed support from the NEA, financial support is provided by several groups, including the American Institute of Architects, the Boston Society of Architects, corporate and private foundations, and leading firms.