Architect Peter Haimerl had long entertained the idea: Why not stack concrete tubes in a hexagonal shape to create living spaces? The interlocking hexagon footprint saves space, and tubes are easy to prefabricate. The honeycomb structure also creates unique living spaces with its sloping walls and ceilings – a healthy departure from the ubiquitous rectangular “shoeboxes” of modern residential construction, as Haimerl sees it.