The practice of investment casting is widely used in the production of industrial, and mechanical hardwear. The process takes advantage of one material’s workability and abundance, to then mass produce high precision copies using a less workable material. The Zephyr Gate aims to incorporate this industrial process as an architectural workflow. The Zephyr Gate is a funneled metal grating consisting of many individual “bricks” that channel and condense breezes to act as a passive cooling system. Each “brick” is precisely cut from high density foam using a hot-wire attachment for a KUKA robot. Given the low cost and abundance of high density foam the material works well as a replacement mold for the final form. Like most industrial practices the foam is coated with plaster before being surrounded by sand to ensure high resolution. Molten metal is then poured into the foam, consuming and replacing to form a metal copy.