Even with its technical bravura and lush public amenities, a project for Google at its headquarters in Mountain View, Calif., faces an uncertain future. The plan included four buildings totaling 2.4 million square feet with lush interior gardens bathed in sunlight through domed greenhouse roofs. He is collaborating with Mr. Ingels, the Danish architect, who thinks much the way Mr. Heatherwick does. (Mr. Ingels roofed a Copenhagen power plant with a ski slope.)