The state affiliate of the U.S. Green Building Council will celebrate Earth Day from 6-9 p.m. April 16 at the celebrated headquarters of Genzyme, 500 Kendall St. Cambridge.

The event, which has no admission charge, is expected to draw architects, engineers, developers, government leaders, and others. After a cocktail reception is under way, the group will announce the recipient of the 2009 Innovation in Green Design Award.

The award is given for a work in Massachusetts — a building, a piece of legislation, an academic curriculum, or other accomplishment — that is innovative, that effectively advances sustainable design, and that can be a model for others. Last year’s award went to Arrowstreet Architects for Artists for Humanity Epicenter in South Boston.

The band Onset will perform afterward.