Prefabrication experiments - 473 - Héliobulle : A «sunlight sphere»

 

Reducing negative environmental impacts and conceiving energy-positive construction systems has never been as important considering the drastic and catastrophic effects of climate change that are visibly modifying our collective landscapes. Prefab has generally been linked to more economical, and energy efficient systems articulated to replicable component fabrication and assembly which curtail construction waste. In previous eras of crises, building system inventors have coupled some of prefab’s advantages with mechanical and natural biophilic conceptions in symbiotic relationship toward complete energetic autonomy. 

 

An architecture of energy systems was best represented by Buckminster Fuller's Wichita house and geodesic dome houses within unfamiliar shapes and geometries made pertinent through their potential for resource efficiency.

 

Fuller's ideas inspired many other experiments, one which is particularly characteristic of the era's zeitgeist. The Héliobulle or geodesic «light-sphere» proposed and patented by architects J. and M. Pattou combined a spherical dwelling with an energy production machine. The icosahedron prototype deployed 20 outstretched triangles in a 3-frequency grid assembled from 180 triangular reinforced and plastic faces. South facing surfaces included solar absorbing elements which channeled power through a central vertical tube connected to a stocking chamber underneath the living floor. In cross-section, five adjustable posts attached to reinforced concrete cylinders cast onsite supported the levitating orb. A wind turbine connected to the central tube served as a complement to the solar energy production. 

 

Mandated by the French Alpine Club, the 6-meter diameter tiny mountain bivouac huts included a furnished ground floor area for living and a loft for sleeping.  The patent describes the sphere as the perfect solar shape; the sun’s rays would always reach at least one of the composing triangular faces perpendicularly at a particular time of the day. Each polyester based monocoque triangle was designed as a layering of either absorbing, undulating, or transparent material depending on its position on the sphere in relation to the sun’s trajectory. Assembled in just ten hours by four people this geodesic sphere certainly expresses its ties to Buckminster fuller's theories of maximum livable space within a minimal lightweight building kit.

Architects' representation of the «Helio-sphere»

 

Prefabrication experiments - 472 - A Perfect Storm for Mass Timber

 

Selected materials and construction strategies embody the era they are invented in. Pozzolanic ash concrete provided Roman builders with an artificial stone to erect vaulted and domed structures that still stand today. Industrialization harnessed new energies for steel and concrete elevating construction capacity for edifices of scopes, sizes and heights impossible to imagine before then. Reinforced concrete, a robust and intrinsically fire-proof material, came to represent the modern industrialized housing block. Casting this malleable and resistant material into shapes reformed onsite construction as surface elements for floors, walls, roofs, and other required components like stairs or balconies could be precast in quantities offsite, delivered and easily assembled onsite. The precast large panel blocks of postwar France epitomize the marriage of a material's properties and overwhelming demand for its use. 

 

Today, critical decarbonization of building activities to reduce construction’s environmental footprint, increasing urbanization and a demand for quickly built housing is stimulating the demand for another twentieth century material:  engineered laminated timber. Both glulam and cross laminated timber are embraced as eco-friendly as their low carbon footprint when compared to energy intensive materials like steel or concrete has unveiled a competitive edge in the age of rapidly evolving climate change. 

 

Engineered laminated mass timber is relatively simple to produce, and components can be fashioned in any geometry and precisely cut as customizable offsite produced kits for building. Parts, slabs, panels, columns can also be normalized or standardized according to spans and dimensional requirements of reproducible building types. The Sylva scalable timber construction system by European forestry company Stora Enso demonstrates the straightforward mass timber approach: post and beam glulam is complemented by cross-laminated elements for bearing or spanning elements. Along with their school kit, Stora Enso produces components ranging from simple linear elements to comprehensive modular volumetric building sub-assemblies to be stacked into multiple configurations. Along with sequestering carbon during their lifespan, if the timber is protected adequately and its joinery designed for disassembly, components can be deployed over multiple lifecycles, making mass timber perfect for low embodied energy building.

School ConstructionComponents by Store Enso