Prefabrication experiments - 443 - Mass Affordability - 04 - Robotic Masonry

 

Expressed by harvesting and arranging local, low-tech materials, masonry construction's character has always conveyed a type of humbleness and affordability linked to its relative simplicity. Building any compressive structural form with dimensionally stable elements geometrically dry-locked or bound with mortar, reinforced or unreinforced, has provided both versatile and long-lasting buildings. Artisan-based masonry construction has also been highly industrialized: Blocks, bricks and binding agents manufactured with rigorous precision, constituent stability and modularity can be stacked for bearing or cladding wythes. Recent labour shortages, specifically in traditional trades, have had many looking at novel ways of introducing digital technology to the age-old process of bricklaying to refresh its pertinence and conserve its historic frugalness. 

Digital fabrication, using robots, is being examined for making complex shaped bricks or blocks to create structurally informed geometries, to stack bricks in intricate patterns that would be difficult for even the most skilled mason, or simply to make quick work of a running bond. Emerging Objects, Gramazio and Kohler or even ShoP Architect's parametric masonry work at Mulberry House in New York present a new set of opportunities and parameters for masonry-based assemblies. Can the link between new technological potentials and affordability be found in replacing an ageing workforce with flexible site-based automation and digital mechanization ? 

Related to how large scale 3d printing is presented to produce affordable dwellings with on-site mechanization, SAM (semi-autonomous mason) and Hadrian X (fastbrick system), are similar versions of numerically controlled robotic arms. Both precisely place units to shape architectural form. SAM, conventionally completes the process of installing cladding by delivering, buttering, and setting bricks at a rate of 3000 bricks per day (500 is the average rate for a mason). Hadrian X proposes a comprehensive house building process. The Fastbrick Wall System is a combination of blocks, adhesive and an exterior acrylic stucco to produce a finished wall. The system could conceivably be delivered to any site. Further the aligned cores within the proprietary blocks are used to reinforce the system with steel rebar and easily distribute wiring and plumbing to produce a comprehensive building system.

top left: Emerging Objects; top center: Gramazio Kohler; top right: SHoP Architects
bottom left: SAM; bottom right: Hadrian X

Prefabrication experiments - 442 - Mass Affordability - 03 - “Unfinished”

 

Providing adequate affordable housing in the context of labor shortages, massive population displacements, and increasing construction costs requires inventive propositions to address an unsolvable problem. Building repetitive pattern houses and designing smaller units have proven to be a way forward in eras and contexts requiring urgent supply. Offsite construction and prefabrication were deployed during similar times of crisis to respond to exploding demand; Even while prefab systems proved an effective way of increasing output, the bare bones construction materials and methods linked to their affordability proved to be their downfall as prefabs became associated with shoddy construction.

 

Another idea linked to reducing costs has appeared from time to time with equally connoted results: providing adaptable systems that can be customized and even finished by their occupants. Unfinished, The DIY house, The Naked House, The Grow Home and even The Half House designed by Pritzker winner Alejandro Aravena identify home finishing as an important part of initial costs. Most of these proposals argued for a mechanical core, structural system, and climatic shell to provide basic and initial dwelling spaces. Elements left for personalized fit out would be completed by owners and as they became economically feasible or required. Some have gone so far as servicing unfinished bathroom and kitchen spaces with plumbing and electrical distribution capped at fixture fittings.

 

The upfront costs of these unfinished houses can be 40-50% less than a comparable finished product. While this can be an economic advantage and even help reduce borrowing budgets, it’s not clear how the long-term finishing will impact overall costs, or if finishing one’s own home is applicable in all contexts, or culturally tainted. Still strategies like The Naked House presented at the Venice Biennale in 2016 as part of a British team of designers proposes generic spaces that can be functionally determined and altered during the home’s lifespan. Reducing upfront material use certainly provides an interesting way of lowering construction costs, however piecework fit outs done one at time, can increase total costs of building providing a framework for higher profit margins and reduced responsibility for builders; a naked house is certainly less expensive than a completed house however it is also just that: unfinished. 

Above left: Wikihouse (DIY); Above right: Half house (Aravena); Below center: Naked House

 

Prefabrication experiments - 441 - Mass Affordability - 02 - State Organized Construction

 

Industrialization and the subsequent marketplace commodification proved that the invisible hand (Adam Smith’s vision of the free market) commanded mass production, by replicating standards, tasks and procedures to reduce costs and normalize quality. A centralized strategy that supports and harmonizes supply chains with design, manufacturing and commercialization is the basis of any successful production strategy.  Similar ideas have been envisioned to provide affordable housing through highly integrated industrial procedures.    Government run factories for precast concrete panels, volumetric modular units and components highlighted postwar production in the USSR as the socialist republics perfected building systems. The panel block was the most iconic result inspired by and patterned over Ernst May's experiments in Germany in the early 20thcentury. May’s ideas were expanded by the USSR’s construction policies. Planning, designing, manufacturing and onsite assembly were all synchronized by a centralized procurement and provision strategy based on typical buildings shaped by a modular grid: a major dimension of 3m with a minor dimension of 30cm, controlled by a rigorously applied 10cm coordination matrix.    This productive model motivated many other countries; An American delegation traveled to the USSR in 1969 to gain a better understanding of the government run factories and study how off-site construction was generating the kind of housing output that the US required. Many of Operation Breakthrough's systems were derived from panelized or precast mega block construction.    Program underwriters’ justification for high levels of industrialization foreshadowed arguments made today: 40-50% less labor, 35-45% faster, higher quality and year-round construction. The Gosstroys, state construction committees, at the republic, local and city levels oversaw all Soviet construction from providing sites, financing, typical building designs, to harnessing new materials, machines and methods. Academic and research institutes governed by the centralized Gosstroys framed research grants according to specific innovation potentials. This concentrated method of decision making certainly made it possible to construct vast amounts of housing, however it also formed some of the negative connotations still haunting construction's industrialization.    Perhaps the lesson for today's housing crisis is the need for government involvement to stimulate and standardize processes while encouraging open design frameworks to avoid the total repetition of patterns that gave us the brutal panel block. Nine storey panel block from 1967 catalogue of typical buildings

Prefabrication experiments - 440 - Mass Affordability - 01 - The Balloon Frame

Urbanization, population migrations, political instability and economic crises engender globalized pressures that make suitable and sustainable housing provision one of the most imperative challenges of the 21st century. The generative potential of manufacturing applied to housing supply provides a renewed topic for reforming longstanding productivity issues in conventional construction. The ten next posts will look at some of industrialization's successful strategies for responding to vast housing crises of past eras.

 

The expansion of populations on a new continent in the early and mid 1800’s outlined requirements for everything from houses to barns, to places of worship and everything in between. The mass adoption of light timber framing, specifically the balloon frame, in the midwestern part of the USA soon branched out to every part of America. As opposed to heavy post and beam construction with complex joinery to ensure stability and durability, the cruder framing required only milled timber and cut nails to create buildings of any type and shape. 

 

Sometimes attributed to George W. Snow, a Chicago carpenter, the light timber frame was not invented but evolved through shared knowledge and the collective simplification of traditional half-timber construction. The system characterized by two-story vertical studs democratized through simple techniques, nailed assembly, is strengthened and stabilized through structural redundancy. Vertical, horizontal and diagonal bracing members placed close together in a filigree box frame streamline supply chains from forestry to mill to suppliers, builders and consumers. The system’s no-frills D-I-Y quality became an integral part of Americana, used to build pattern buildings, cottages, cabins, A-frames, and provided the basis for the most successful application of low-cost manufactured housing principles: the mobile home. 

 

Today’s version of the balloon frame, known now as the platform frame is still one of the most economical and generalized building structural archetypes. Included in panelized structures or modular volumetric structures, the mass production of cheap, standardized, well recognized and available building components is a central principle of lowering costs. The design flexibility from the same simple parts also displayed light-framing as a model the world over for low-cost and low-tech building.

left: Balloon Frame; right: mobile home framing

Prefabrication experiments - 439 - Catalogues and styles

 

A spinoff of the spawning 20^th century automobile industry, early mobile home manufacturing deployed mass production principles to build affordable dwellings. These principles are well documented; building a lightweight timber structure over a steel platform, wheeled out of the factory, delivered and installed on any site. The pre-cut kit house also used mass produced timber frames but from a different value proposition in as much as its design process offered increased options; pieces could be shaped and packaged for multiple configurations less affected by transport criteria. 

 

Both models of twentieth century prefabrication used plan books to organize procurement. Clients could choose from designs articulated to harmonized modular strategies and supply chains. The Sears catalogue of houses is probably the most famous and inspired other companies like Canadian icon Eaton to offer their own version. The number of designs was staggering when analyzed in relation to what architects often decry as standardized prefab. 

 

The conceptual distance between how industry and architects interpret the catalogue endures as an interesting dilemma for manufacturers. While architects have often argued against style to inform patterns and pastiche architectural compositions, their proposals remain relatively similar in terms of fundamentals differing only in aesthetic orientations. Resolution 4 architecture's took on the modular catalogue «The Modern Modular» with what at first glance seems like a third option: A library of spatial components and modular variability anchored to an objective of spatial and production rationalization. However, the aesthetic remains manifestly modern defined by clean and minimal lines. 

 

Is architectural variability truly about singularity or is it about style. The Eaton catalogue contained traditional designs outlined by similar detailing and volumes, while Res4’s architectural approach more closely mimics a type of pattern language leading to houses that all look the same, hardly singular. Industry’s take on the precut house was in a sense at once rational and varied. Contemporary architects argue that prefab should be organized around similar components, nonetheless, mostly tainted by modernist attitudes. This aesthetic and disciplinary-informed gap between architectural sophistication and generally palatable designs continues to hinder prefab’s streamlined application.

left: Eaton Catalogue; right: Resolution 4 Architecture modularity