Stair And Lift Core

4x4m circulation core tower on the 2m grid, three floors at exactly 3m with the roof at 9m plus a lift overrun box, glazed stair slot showing landings at each floor level, flat walls on the footprint edges so it plugs onto any block face.

风格：low-poly, flat-shaded vertex colors, no textures, single shared material, so any set of these merges to one draw call; shares palette and scale with its kit