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

Prefabrication experiments - 438 - Concrete Tube Utopias

 

The previous blog posts have discussed housing types from micro-dwellings to industrialized utopias and large-scale urban renewal proposals. Each motivated to efficiently supply quality dwellings for the masses affordably and with sufficient flexibility to respond to varying dispositions. Current generalized urbanization challenges existing models toward the production of dwellings while simultaneously reducing our collective environmental footprint.  Conventional housing construction is a slow go, fraught with planning delays, bogged permitting and symbolized by lagging productivity. 

 

Repurposing ready-made industrialized objects for housing urgencies is a recurring theme and has spawned an assortment of schemes including converted shipping containers or stacked mobile homes. While designed in different eras, two proposals demonstrate the cyclical nature of architects inspired by redirecting manufactured products for other uses. Guy Dessauges (Living Tubes, 1966; blog article 28) and James Law architecture have both represented concrete infrastructure pipe sections as modular building blocks for quickly putting flats together. Dessauge’s tubes were envisioned around a centralized service core or stacked three stories high composing a housing hive. The Opod Tube House (2017) proposal visualized in multiple contexts clearly borrows, consciously or subconsciously, from the same Zeitgeist.  

 

Can lessons be learned from these radical investigations for creating affordable housing or are they just exercises architects have come to adopt as their discipline’s way of addressing crises? The amount of rework needed to adapt products to housing is often absent from designs and sometimes asserts disciplinary caprice. The discipline’s «modern» heritage of rewiring industrial designs to imagine novel building systems reforming classic ways of building is entrenched in this type of poetic license that has often led to socially, economically and culturally untenable proposals. 

 

Most architects are far removed from economics, manufacturing and streamlined production that the only way they feel that they can contribute to solutions is by resorting to romantic views of prefabrication as the simple assembly of premade forms. The truth is that adapting ready-mades can be complex: mechanical systems, interior infill, site infrastructure and other retrofit requirements makes this type of stacking less than credible and financially unfeasible.

above: Opod; below: Living Tubes

Prefabrication experiments - 437 - XL(towers) - Vertical neighborhoods

 

Relating the advantages of the single-family dwelling (privacy, spatial distribution on multiple floors, four orientations for views and exterior spaces) with the benefits of collective housing (density, shared services, proximity) has inspired architects since industrialization created an magnifying need for affordable urban housing prototypes. The last few blog posts have referenced Le Corbusier's Unité d'habitation based on amassing rationalized two-floor flats, Metabolists’ plugins aggregated over shared towers along with an idealized view of a multi-floor infrastructure to accommodate homes represented in Site Architect’s Highrise of Homes (1981).

 

The flagship endeavor for this productive vision of high-rise suburban living is Habitat 67 constructed for the Man and his World exhibit in Montréal, Canada (1967). The modular prestressed and post-tensioned concrete mega-blocks were cast and amassed to create an architectural statement about the potential future of housing that never manifested. Still this architectural dream endures in its most at once naive and foreword looking manifestoes. 

 

Chicago studio Kwong Von Glinow  projected a tower of multi-story houses for Hong Kong. The design won first prize for the Hong Kong Pixel Homes competition in 2018. The modular boxes would be stacked up to four high to organize single houses and apartments vertically instead of the horizontal relationships conveyed in conventional planning. Juxtaposed single, couple and family units are intended as a type of vertical unit – a neighborhood - activating dynamic collective spaces between units. The interiors could be fit-out according to inhabitants’ needs and eventually evolve over time. While the theoretical proposal is rendered to showcase a mass to void relationship that allows for vertical patios, views and rich interior/exterior relationships, the real-life viability remains to be proven. Designed in groups of four stories, the proposal echoes the need for a type of primary support structure to carry each stacked neighborhood, which would allow for streamlined replication of modular units. As developed in a timber tall building in Norway, Treet, the four-story stack built on a infrastructure floor is a credible option for realizing this contemporary take on the vertical distribution of individualized dwellings.

left: Pixel competition design ; right: Treet section showing two «support» floors

Prefabrication experiments - 436 - XL(towers) - Stacked dwellings

 

Skewering identical floor plates on a vertical axis is the most common way of building dwelling towers. The inhabitable hives are optimized by aggregating units effectively around centralized service cores. Composing tall buildings with variable floorplates, while certainly less commonplace, has inspired many architectural proposals based on adaptable floors conceived as free indeterminate spaces tuned to present needs as well as being adjustable to change over time.

 

The tension between pragmatic building strategies and individualizable housing needs arguably also led to the invention of both the megastructure tower and the development of open building theory. SITE architects' evocative representation Highrise of Homes (1981) or Elmer Frey’s stacked mobile homes, both represent the underlying duality of any collective housing scheme of according common and private functions. The floor plate designed as infrastructure for any organizational scheme harmonizes these parameters and inspired examples of the support versus infill patterns related to Habraken's visions for mass housing.

 

Isay Weinfeld, IW Arquitetura's 360° tall building in São Paulo, Brazil is a contemporary vision of particularizing tower geometry with varying and open slabs. Each storey is composed of large spanning reinforced concrete, onsite cast, waffle slabs cantilevered from a rigorous grid of columns and central service core. Each floor is infilled with modularly organized flats shifted from one floor to the next in a pinwheel composition to enhance the tower’s dynamic form. Further, the 62 units are massed to create voids identified by their designers as yards revealing a vertical urban plan imagery for the tower. 

 

The stacking of identical units into an accommodating slab frame makes it possible to manufacture systems as completely replicable chunks without the habitual reinforcing required for lower modular units or elements to support their vertical neighbouring units. The 360° tower demonstrates the enduring architectural attraction for customizing interiors in a structure as a service rack of endless possibilities. This approach, while distant from Japanese Metabolists’ complete plug and play theories reveals how Sites' representation of an ideal customizable vertical city is still a forceful fantasy in architectural culture. 

top left: Highrise of Homes; top right: stacked mobile homes; bottom: 360° Tower

Prefabrication experiments - 435 - XL(towers) - Taller is better

 

Occupant protection is a fundamental purpose of housing. Defensive posture is usually defined by how a home is anchored to its locus. Dugout or elevated, position relative to ground plane symbolizes how humans delineate their territory and how they interact with other humans; The need to observe surroundings, showcase one's wealth or power, and dominate the environment stimulated the development of the tower house type. Cities in the middle-ages were stages of power struggles represented by the multiplication of elevated dwellings as devices for celebrating a family's wealth - taller was always better.

 

Verticality as an expression of wealth and power took on a manifestly modern connotation as new materials and construction methods made it possible to reach greater heights and spans unlocking a potential for spaces, commercial or residential, to be stacked democratizing what had been theretofore limited to the ultra-wealthy. Mechanization, steel, reinforced concrete and light curtain walls unleashed new industrial energies. The tower became a symbol of urbanity powering new cities into the twentieth century no longer related to one family. Granted, many private promoters and construction magnates were still sometimes controlled by a family who continued to prove their influence by harnessing resources and deploying them into magnificently tall buildings. 

 

The tower as a multi-unit dwelling typology is straightforward: flats are distributed, aggregated and piled around a central core containing mechanical distribution and circulation. Flat typologies, anchored to a core, can be one, two and sometimes three stories high with single, dual, triple or quadruple orientations depending on the core-to-flat configuration. The typical floor plate repeating the systemic relationship from floor to floor makes these edifices conducive to rationalized construction methods. 

 

Modular volumetric construction has been proposed, marginally applied and offers a glimpse into the strategy's potentials and limitations. While certainly formidable in terms of speed of construction, in conventional systems, lower boxes carry the weight of upper boxes. Tall prefab and modular construction using repetitive units imply the use of an expressed or hidden support structure or the particularized reinforcement of each manufactured box, which makes the seemingly simple stacking challenging in terms of mass production and can also increase construction costs. 

above: Bologna tower houses; below: Capsule tower by Kisho Kurokawa

Prefabrication experiments - 434 - XL(slabs) - Umbrellahaus TM

Modular volumetric construction is characterized by three-dimensional, factory produced boxes. This approach sometimes associated with slab buildings, is generally based on repetitive structural grids conducive to typical floor plates; flats with similar dimensions and attributes are simply stacked and coupled. The slab typology doesn’t expressly direct to volumetric as the sole solution for putting these buildings together, however, coordinated, transportable boxes can certainly streamline certain parts of a construction timeline. Further, modularity can be leveraged toward scaling container-like flat types among many housing projects using the same basic structural elements and systemic components - a strategy now identified as a platform approach to building. 

 

Designed and trademarked by Chapman Taylor www.chapmantaylor.com   Umbrellahaus deploys the current interest in offsite along with modular volumetric reasoning in the UK to demonstrate a building «platform» to tackle current housing shortages. Suites are outlined by industrial parameters, notably, manufacturability, transport maximum dimensions, assembly and setting details. All apartment unit sizes follow the London Plan space standards.  These design and production considerations are matched up with a variety of lifestyle compositions to propose an array of dwelling configurations from studios to family apartments within the overall framework of a slab building.

 

The concept encompasses more than just modular volumetric construction as it proposes to connect new buildings to their contexts proposing a multifunctional urban infrastructure to avoid the segregation and difficult living conditions connoted by mono-use post-war prefab block neighborhoods. Once the units are stacked in place, several cladding or material solutions can be applied to suit site conditions, architectural tastes and building arrangements. Standardizing design criteria along with a streamlined regulatory approval and a liability framework, the Umbrellahaus platform covers every aspect of the project procurement process.

 

The proposal also addresses long-term adaptability; inhabitants could change from one unit size to another as their circumstances change, without leaving the building. While this certainly can help overlay the units’ design options in tune with lifestyle evolutions - it remains unclear how this theory would be put in place in a densely populated building.

Modular volumetric Umbrellahaus

 

Prefabrication experiments - 433 - XL(slabs) - Streets in the Sky

 

Known for their important contribution to Team 10, an architectural collective formed from the Congrès Intérnationaux de l'architecture moderne's (CIAM) dissolution, Alison and Peter Smithson’s theories and projects were a fundamental part of nascent postwar brutalist visions and pedagogy in the UK and abroad. Mat-building previously discussed in blog article 282 envisioned urban form that rejected buildings as singular objects, exploring instead a symbiotic spatial relationship between urban geometry and building topologies. 

 

The couple married in 1949 and founded their own firm in 1950.  Their radical visions for integrating public spaces in collective housing led to imagining access walkways as «streets in the sky» redefining the slab type. The iconic Robin Hood Gardens, a social housing complex in East London, demonstrated the use of exterior access corridors at different levels large enough to support both personal and social spaces. Their design deconstructed the classic slab by placing these common voids within the structure's volume. A proposal, Terrace Housing City, took this one step further by arranging an oblique slab cross-section as a series of vertical volumetric setbacks from floor to floor flooding each floor plate's exterior skywalks with sunlight. The Streets in the sky imagery influenced many social housing proposals aiming to attribute streetscapes' spatial richness refuting the boring interior corridors synonymous with the slab. 

 

The construction of floating social spaces including roof terraces had already been proposed by modern architects, proficiently by Le Corbusier. Aerial passageways leading to flats became a symbolic component of these modernist visions and were applied most notably at Habitat 67 designed by Moshe Safdie.  Contemporary architects also reframed and refreshed the same objective of social interaction in a dense block: French architect, Jean Nouvel, designed a ship like cross-section at Nemausus in Nîmes, France, with large promenade decks. Multiple meters wide, the catwalks leading to access and exit stairwells were planned as a way of rationalizing costs by externalizing costly elements usually built within the slab. Their removal allowed for them to be built with lighter construction systems and materials redirecting these potential economies to offer larger housing units.

Sections though aerial walkways

Prefabrication experiments - 432 - XL(slabs) - ZUP at Bayonne

 

Interwar years in France intensified dwelling as well as urban hygiene crises. An estimated 5 million units lacked running water and basic services. The devastating damage to hundreds of thousands of buildings during the second world war exacerbated this need for quality housing. In response, centralized policy sanctioned new dense developments all over the country under the label, ZUP - Zones à urbaniser à prioriser (liberally translated to Priority Zones to Urbanize). Projects and their promoters which provided a minimum of 500 units in tightly packed edifices required affordable and efficient construction methods to be deployed at scale. 

 

The slab block was adopted by an industry increasingly articulated to reinforced concrete; a material the country's inventors (Hennebique, Monier, Lambot and many others) had been central in cultivating. Beyond the material's advantages in terms of fireproofing and strength, it also lent itself to all types of prefabrication strategies. Marcel Breuers' flagship ZUP design for 1100 units at Sainte-Croix/Saint-Esprit, in the small community of Bayonnne explored precast concrete construction to propose a formidable building system. Designed and built from 1963 -1967, the master plan included dwellings and several services including a school and shopping center.  

 

Using a factory cast wall panel system inspired by the Camus System (also invented in France), Bayonne buildings were arranged as a cellular hive of flats and simply covered in a precast thick panel. The basic structural strategy of walls and slabs at Bayonne was cast on site using a tunnel form system:  a moveable prismatic formwork that defines a cell with a horizontal plane supported by two vertical planes. The tunnel forms are usually made of steel. Once the concrete is cast, the steel framed-moulds slide out and are reused on subsequent floor plates. 

 

The heavy wall panels’ architectural treatment at Bayonne showcase Breurer's talent and understanding of prefabrication's potential to create dynamic façades using mass manufactured components. The panels were cast as a thick solar shading device with built-in furniture and window openings. A mirrored pattern was repeated every two stories creating a textile like façade; the project's simple renderings illustrate how architectural regularity defined a coherent material field. 

Rendering of the Bayonne master plan

Prefabrication experiments - 431 - XL(slabs) - A failed prototype ?

 

Generated from industrialization and its new construction materials, specifically, reinforced concrete, the slab building was forged by assembly line production and its accompanying design theories. Thin, linear, rigorous grid organizations simplified structural design and service distribution, making these replicable arrangements ideal candidates for scaled serial production. The linear apartment blocks repeat floor plans and extrude sweeping vertical sections that sometimes seem to go on infinitely. This regularity is what made the slab a formidable affordable housing strategy but what also ultimately embodied the downfall of this expressly modern type.

 

Inaugurated in 1954 in St. Louis, Missouri, Pruitt-Igoe's 33 high density buildings underwritten by federal policy heralded the post war enthusiasm and urban planning doctrines associated with the slab block. The experiment like so many other modernist developments was rife with economic and social challenges.  Its symbolic demolition only years after its construction refuted modernist ideologies of mass housing.

 

Still, the slab endures as an iconic composition of flats designed to optimize collective and social cohesiveness. These buildings offer a rational way of using the same principles that gave us terraced housing but scaling them to taller structures. Recent proposals deploy the same underlying ideas to produce buildings from a generic aggregation of flats contextualized in mixed-use settings to counterbalance flawed modernist functional segregation. 

 

A contemporary example of a contextualized slab designed by Arrhov Frick Arkitektkontor in Sweden, is composed of a dual-oriented adaptable loft inspired units.  The typical floor plate of the Hmmarby Gård project is a multiplied sequence of two flats articulated to a shared vertical circulation core and arranged around a service hub surrounded by flexible living spaces.  13,6 meters wide, flats include large balconies on their north eastern façade and operable curtain wall façades on the opposite connecting the see through building to its surroundings. The repetitive plan makes a case for modern industrialized principles, repetition, modularity, standardization. This reproducible sameness that was decried more than half a century ago is valued as fashionable and mass customizable, elevating the slab from a once promising but failed prototype into a dynamic way of breathing new life into a city.  

Hmmarby Gård typical floor plan