Prefabrication experiments - 174 - Geometries - 05 - Inhabitating polyhedra

Using geometry to redefine and reform traditional architectural compositions was one of modernism’s defining attributes. Simple white prisms or ascetic steel skeletons informed by strict modular rationalities came to express architectural modernism in the early twentieth century. From LeCorbusier to Mies van der Rohe, a union of classical geometry with industrial principles underpinned most modernist grids. 

Geometry also informed a later modernism based not on aesthetic ideals but on principles for improving construction and structural efficiency. R. Buckminster Fuller, Frei Otto and Felix Candela employed geometry to optimize structural form for spanning large areas with the least amount of material. Still another vector for geometry in architecture was developing formal archetypes and shapes that are non-traditional and originate simply from experimenting with geometric arrangements. The architecture of Zvi Hecker undeniably falls into this category. 

Developing shapes inspired by a type of crystalline modularity, his work with the firm of Neuman, Hecker and Sharon is especially noteworthy in this regard. Juxtaposing regular polygons into patterns made the geometric assemblies. The firm designed a series of temporary shelters based on geometric patterns. The projects were undertaken in the early 1960s, the first at Ahziv and the second at Michmoret. Both proposals sought to reinvent the modern tent. The systems were to be lightweight and easy to assemble. The basic unit was a site assembled hexagonal panel framed in light timber and filled with reeds wired and pressed together in a linear pattern. The reed mat within a hexagon edge produced panels, which became the faces of varying polyhedra. The edge segments were either joined together or left open for access, light or ventilation. The micro dwellings were large enough for two or three people. The 6-foot diameter panels joined together produced a truncated octahedron. The formal expression of each cabin was completely foreign to traditional housing typologies but the lightweight reed surfaces integrated local vernacular.

This geometric regionalism is synonymous with Hecker’s work. His many experiments with polyhedra endeavoured to make complex geometric forms socially acceptable. However, Hecker’s singular objective was to express an original architecture beyond regular right-angle volumes.

First project at Ahziv

Prefabrication experiments - 173 - Geometries - 04 - Pond Inlet «Y» house

The Nissen and the Quonset hut are examples of directing unsophisticated barrel vault geometry to building construction. The form resistant semi-circular half pipe arching steel structures were employed for military hangars or storage and also marginally as dwelling prototypes. The tied-down half cylinder composed of arched steel sections covered in corrugated cold rolled steel performs, physically, as an extruded compressive arch. Its curvature is braced by either foundations or tie beams acting as abutments.  A variant, the complete cylinder, tube or whole pipe has also been explored as a type of ready made architecture. 

Severe settings, framed by either harsh climates or problematic access or both, require inventive housing strategies that can be constructed with minimal disturbance while optimizing performance.  Both the half and whole pipe have an intrinsic structural capacity and can be easily assembled. These properties and a potential for generating geometric patterns is displayed by a Y shaped pipe house designed by architect Richard Charbonnier on Pond Inlet, Nunavut. Situated in Nunavut’s Baffin Island (69˚N72˚W) the prototype is a result of the architect’s continuing research and exploration into arctic dwellings.

Fusing three aluminum barrel / cylinder structures into a Y shape, the structure hovers over the arctic expanse.  The Y is anchored to three concrete piles with tripod connectors. The pipe’s curves reduce wind resistance and the snow (heaps/piles) habitually produced on the leeward side of standard prismatic arctic building types. Resembling a perched culvert ready to be completed into some type of plumbing infrastructure, the cylinders play more than an aesthetic role distributing heat evenly and the seamless eaves and joints reduce weak points ensuring complete weather tightness. 

Inspired by the Igloo and elevated over the shifting permafrost, wall, roof and floor are protected by a seamless aerodynamic windshield.  The inhabitable Y fitting exposes particular details shaped by climatic demands. The projecting cylinders screen small porthole windows and doors reducing heat loss and establishing a type of antechamber against the stormiest of  40˚C days. A central skylight located at the Y’s intersection exposes a three-zoned plan allowing the arctic moon as well as the summer sun to punctuate the interior layout.

«Y» house in the arctic

Prefabrication experiments - 172 - Geometries - 03 - Sunflower swimming pools

Domes have been used too cover architectural space since ancient times. The form resistant shell structures are particularly efficient regarding compressive strain and effective in large spanning structures, as the dome’s rise will increase according to span using geometry to counteract loads. Hemispheric or less than hemispheric domes are structurally pure types that can be assembled by corbelled masonry, thin shell concrete or skeletal filigree components. Skeletal structures such as geodesics are conducive to prefabrication as their circular array geometry facilitates repetitive tessellations of each sector’s composing elements.

The Piscine Tournesol (sunflower swimming pools), a result of France’s large-scale post war building programs during an era of prosperity and growth, was a prime example of unifying simple geometry with prefabrication to serve the nations growing demand for buildings of every type. Architect Bernard Schoeller was responsible for the prototype design that yielded 180 swimming pools in the early 1970s. The dome’s structural system encompassed a circular arrangement of arching girders or joists spread out from a central point. The girders compose 64 equal sectors that make up the rooftop's basic geometry.  Two 60-degree sectors were designed to rotate over rails and reveal a great opening. The resulting 120-degree aperture fashioned a giant doorway relating the pool’s interior to the adjacent landscape. The two large sectors slid underneath the major 240-degree sectors in opposing directions aligning portholes directly beneath each other. The arched joists were attached to a central compression ring and to the circular foundation wall acting as an abutment or in this case as a tension ring withstanding any hoop stresses in the lower part of the structure.

Strangely evocative of Futuro houses designed by Matti Suuronen, polyester (glass fibre reinforced hardened resin) panels glazed in a naval inspired gel-coat finish, were affixed to the steel girders. Each panel was a three layer composite sandwiching an expanded phenolic foam core. The panels were essentially the dome’s skin, including exterior and interior surfaces, transferring compressive stresses through the girders while the hoop stresses were contained by simple horizontal bracing between the girders. The large spanning structures covered a 35-meter diameter rising 6 meters above the water level. The plastic panels pierced with rectangular porthole type windows reinforce the dome’s long-established artificial sky reference. 

Aerial views showing the great opening