Development Seed is located above the Dabney Restaurant. To the right of the Dabney is a door with the Development Seed Logo. Through that door, follow the sidewalk to its end. There you have two options: 1) Take the stairs on your left to the second level and through the glass double doors. 2) For a more accessible route, call up from the call box in order to get access to the elevator.
FYI if opting to use the elevator, you will need to ring Development Seed on the intercom.