The design for the new addition utilizes sustainable building concepts; the sculpture garden continues up and over the gallery roofs, creating sculpture courts between the lenses, while also providing green roofs to achieve high insulation and control storm water. At the heart of the addition's lenses is a structural concept merged with a light and air distributor concept: "Breathing T's" transport light down into the galleries along their curved undersides while carrying the glass in suspension and providing a location for HVAC ducts. The double-glass cavities of the lenses gather sun-heated air in winter or exhaust it in summer. Optimum light levels for all types of art or media installations and seasonal flexibility requirements are ensured through the use of computer-controlled screens and of special translucent insulating material embedded in the glass cavities. A continuous service level basement below the galleries offers art delivery, storage and handling spaces, as well as flexible access to the "Breathing-Ts".