Prefabricated and Modular Architecture E-Book

William Hogan-O'Neill

• Herausgeber: Crowood
• Kategorie: Geisteswissenschaft
• Sprache: Englisch

Veröffentlichungsjahr: 2021

Beschreibung

Prefabricated and Modular Architecture demystifies age-old perceptions surrounding prefabrication and modularization of buildings, offering a fresh approach to design and procurement. Experienced architect, William Hogan-O'Neill, provides a unique insight into why architectural design, manufacturing and assembly processes must coexist in parallel. In order for the architectural profession to have a meaningful existence in the future, it must examine the new opportunities that are emerging through automation and artificial intelligence from within the factory environment, as opposed to the construction site. In addition, the book explores the following topics; core elements defining prefabrication; perceptions and influences; precision, exactness and tolerances; standardization and economies of scale; panelized versus modular buildings as a design solution and, finally, common features, technical considerations and certification.

Leseprobe

Aligning Design with Manufacture and Assembly

WILLIAM J. HOGAN-O’NEILL

First published in 2021 by

The Crowood Press Ltd

Ramsbury, Marlborough

Wiltshire SN8 2HR

[email protected]

www.crowood.com

This e-book first published in 2021

© William J. Hogan-O’Neill 2021

All rights reserved. This e-book is copyright material and must not be copied, reproduced, transferred, distributed, leased, licensed or publicly performed or used in any way except as specifically permitted in writing by the publishers, as allowed under the terms and conditions under which it was purchased or as strictly permitted by applicable copyright law. Any unauthorised distribution or use of this text may be a direct infringement of the author’s and publisher’s rights, and those responsible may be liable in law accordingly.

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library.

ISBN 978 1 78500 807 8

Dedication

To Frieda

Contents

Acknowledgements

Introduction

Chapter One

Prefabrication – Definitions and Explanations

Chapter Two

Perceptions and Current Influences

Chapter Three

Fabricating the Architecture

Chapter Four

Standardization and Prefabricated Solutions

Chapter Five

Prefabrication Through Panelized Construction

Chapter Six

Prefabrication Through Premanufactured Volumetric Modular

Chapter Seven

Features Common to Panelized and Modularized Buildings

Conclusion

Bibliography

Glossary

Index

ACKNOWLEDGEMENTS

PREFABRICATED AND MODULAR ARCHITECTURE has been my passion for many years and together with colleagues at HOCA Practice I set about to deliver an alternative approach to the conventional way of practising architecture. I am grateful to colleagues who share a similar commitment to my own.

There are numerous persons who during the preparation of this book were extremely forthcoming with information and to whom I am indebted. I must, however, particularly mention Costi of TRJ Construction Ltd, Shaun Foy of Frame Homes (SW) Ltd, Daniel Walker of Kingspan Timber Solutions Ltd, Chris Tonkin of Structural Timber Projects Ltd, Simon Beale of TMP UK South Ltd, Paul Farrelly of CIMC MBS Ltd, JJ Smith & Co. (Woodworking Machinery) Ltd and Mark Jenkins of Kingspan TEK Building System, all of whom have my sincere gratitude for responding to my questions and providing a wealth of information.

I do not hold a monopoly on passion for prefabricated architecture. My research into historical features on prefabricated housing allowed me to liaise with Jane Hearn of the Prefab Museum, to whom I owe massive thanks for the wealth of information she imparted to me.

I must mention my friend and professional colleague Paddy Doyle, whose energy and commitment to prefabricated and modular buildings are inspirational and with whom I continue to enjoy special occasions discussing matters surrounding the world of prefabrication and modular buildings.

This book would never have been possible without the perseverance and support of my wife Frieda who made space for me to function with ease and who put life on hold until its completion, as well as managing the proofreading regime.

INTRODUCTION

WHEN EXAMINING THE ATTRIBUTES AND constraints associated with prefabricated buildings through panelization or modularization, the discussion usually comes first to housing. Housing shortages have a history dating back to the Industrial Revolution and have remained acute since the start of the twentieth century. This continues today, two decades into the twenty-first century. For many individuals and communities, the impression that prefabrication evokes will centre around housing. There has likewise been an interest in applying prefabrication to health care, education, recreation and similar community projects but none of these stimulates such profound emotions as housing.

Notwithstanding the degree to which current trends demand ever more adherence to economies of scale, sustainability obligations together with ecological challenges, many government departments and housing associations are now seeking to identify how the once more forthright ‘system building’ ideology of the past could be used in a more compliant manner to satisfy current demands of house buyers, funders and the architectural fraternity’s design criteria.

The potential for satisfying many of the pressures associated with education, housing, health needs and similar projects is real and acknowledged by prefabricated projects already completed. Within the British Isles, prefabrication has been less than successful in delivering building solutions over the past decades. This is primarily because of previously held perceptions. For now, prefabricated and modular architecture can only be considered as a ‘work in progress’ enterprise as a significant measure of reluctance continues to prevail. Beyond this immediate challenge in prefabrication lies a further vision for exploring current technology and assembly techniques to facilitate high-rise projects where modularization is at their core. Prefabricated and modular architecture continues to forge a space in the minds of some construction professionals more than in architects, albeit at a slow pace, but the indications suggest it is becoming a design specialism that architects should not ignore.

Defining prefabricated and modular architecture can be a very emotive endeavour, not just by how it is identified or referred to but also by the manner in which it is applied in creating buildings. Within the construction industry, one fraternity will maintain that prefabrication, or any product derived from the off-site manufacturing (OSM) process, as not contributing to architecture, but is primarily a process which serves the on-site construction process as its defining purpose. Others attached to the conventional construction ethos might subscribe to OSM as being a vehicle to deliver building projects more quickly, but would prefer not to have to surrender a significantly large sub-contractor package to a specialist manufacturer outside their direct control, potentially impacting on their own overall profitability.

Current thinking within certain design fraternities, too, often sees prefabrication and modular buildings as a particular design and build specialism. It is often viewed as a means primarily to facilitate the architect’s overall architectural design or as a convenient vehicle for delivering a specialist sub-contractor design package through the main contractor. Architecture, on the other hand, should be seen as a whole series of considerations for delivering buildings and design solutions of which prefabrication is one. These design considerations are likely to include the following: design where spatial arrangement is considered relative to its intended function; the selection of materials in relation to function or context and locality; the building’s robustness relative to climate or intended performance; and the actual site context in relation to its surrounding built environment. All of these embrace the building’s architecture. For prefabrication to communicate meaning and status within the building’s architecture therefore, architectural design must also embrace the fabrication design of the components with their manufacturing and assembly entities as a natural part of the total architectural design solution for the site. For many centuries, however, methods employed in delivering buildings have been monopolized by conventional on-site hand-built construction practices conforming to familiar customs and procedures. By contrast, within the UK over more recent decades especially, the reliance on past generations of construction methods and preferences is coming under a number of significant challenges on a number of levels. At long last there is a call from government for ‘the client’s professional team or advisers to adopt a different approach’ (House of Lords, 2017–19, p. 30) by enabling off-site manufacture as a means of expediting a change of emphasis from conventional construction to factory manufacturing and industrialization.

This book explores some principal features surrounding prefabrication applications and processes. It will introduce clients, construction professionals, architects and professional designers, students and private individuals to many of the typical core elements surrounding prefabricated and modular architecture and set about debunking the myths associated with prefabricated buildings. A valuable insight of necessary interactions associated with on-site activities and OSM and assembly processes is examined, highlighting what it takes to approach a prefabricated project, whether it is delivered through panelization or modularization. The distinction is made between on-site construction and manufacturing and assembly, and how the manufacturer’s installation and assembly processes at the site now seek to substitute for over 90 per cent of the conventional site construction activities. The competition that exists between conventional construction and OSM alternatives remains a formidable stumbling block in the minds of many, but current trends indicate negative perceptions are on the wane, with prefabricated and modular architecture now recognized as a dedicated design and manufacturing specialism.

Chapter One

Prefabrication – Definitions and Explanations

Origins and Early Applications

Nomadic Tent Architecture

Early nomads were among the first engineers and users of prefabrication that we would recognize today. We associate nomadism as a lifestyle of moving from one place to another, suggesting an attentiveness to portability and all the inconveniences associated with such a way of life if compared to life within a settlement. Whilst they were not equipped with the benefits of an industrialized off-site manufacturing (OSM) process that we would recognize today, the solution available for them to provide their mobile home was nonetheless facilitated by a simple kit of parts; namely, a timber-framed structure covered with a patchwork of skins. The assembly process associated with the early nomadic tent was, by and large, similar throughout various regions, although the circular ‘plan form’ layout and size might have varied within different nomadic cultures and would have evolved further throughout the centuries, even up to the present times. The circular plan form of the ger is a natural and obvious choice in exposed locations for the Mongolian nomads of Central Asia as the circular structure has less resistance to wind. Wind and water move naturally around a circular building with greater ease than compared to a square-cornered structure, and our present-day obsession to manage air tightness and water ingress remains omnipresent. Similarly, a rounded roof will facilitate further by preventing ‘air-planing’ in strong wind conditions which can cause the roof to be torn off a building.

The essence of the traditional Mongolian ger, meaning home, or yurt in Turkish, extols the epitome of simplicity. They consist of expandable timber lattice wall sections which, when opened up to a given height, form a circular plan arrangement when connected together. Straight timber poles (rafters) form the roof which connects the circular crown to the top of the circular lattice wall structure. The crown, or tono, is a special piece of craftsmanship, often handed down from one generation to the next; it forms a central tie at the top of the structure and at the same time, creates a nucleus within the space where the fire for cooking is located, allowing smoke to dispel at high level. This simple building concept is applied even today in recreational enterprises that are located in natural environments deemed to be particularly sensitive, such as forests, ski-huts, wellness and retreat centres and lodge sites. As such they are not considered to be a formation of a built environment as we would describe them in today’s context, primarily because these structures are not permanent and can be removed within hours.

Traditional Mongolian ger (‘yurt’ in Turkish).

The tono, central piece that forms the nucleus of the family’s ger.

For early nomads, mobility remained a prerequisite for exploiting food resources that relied upon tending their livestock at various locations at different times and climatic conditions during the year. Such a way of life dictated the necessity for creating a shelter from the elements and, in some instances, doing this in very severe climatic conditions, varying from extremely cold to excessively hot. One common feature for nomads living a life on the move necessitated the capacity for them to be able to move camp from one location to another as circumstances dictated and this is reflected in the ease with which they were able to pack up their temporary home and move. It is understood this operation could be completed within the daylight hours of the shortest day, facilitated mainly by the simplistic methods of disassembly and erection with materials specifically employed for the purpose and it is this distinct feature of nomadic life which differentiates them from the settled peoples. Modern-day nomads have the ability to dismantle the ger, pack up their entire building and load it onto a small truck within four hours, such is the level of sophistication associated with their prefabricated homes. The earliest form of prefabricated building, therefore, had its origins in architecture on the hoof but in more current times it is from the rear of a small truck, where flexibility and portability, together with ease of assembly, remain and form the prerequisites for the chosen lifestyle.

Mongolian ger under assembly.

For the UK, history directs us to the earliest contribution of formalized prefabrication to the period of Britain’s colonization when, in the mid-sixteenth and seventeenth centuries, the impetus to establish settlements was uppermost in locations like Australia, New Zealand, North America, India and so on. R.E. Smith (2010) refers to timber-framed components for housing being manufactured in Britain and shipped to various locations. It would be reasonable to suggest that for the users of the early nomadic tent or the British settlers’ timber-panelled house, their relationship with the new environment within which they were sited was not identified in the context of architectural principles or planning rules but more for the structure to perform the function for which it was intended.

Manning’s Portable Cottage

John Manning, a London carpenter and builder, had a clear and simple vision for providing immediate accommodation for his son landing in Australia in 1830. He was perhaps the pioneer in prefabrication as we might identify with today, although this was not obvious to the building industry at the time. Later known as the Manning Portable Colonial Cottage for Emigrants, the house was an expert system of prefabricated timber frame and infill components (Smith, R.E., 2010).

Manning’s Portable Colonial Cottage for Emigrants.

Simple timber panels were easily assembled within his workshop and, when secured together, provided the means with which to create a basic building structure and enclosure in one exercise. Here the wall panels were employed to perform the structure as well as the infill, very much akin to the conventional practice with masonry structure, except that for Manning the structural wall panels were manufactured off-site and transported to the site (the colonies) for assembly. This very simple concept, synonymous with the principles of mass production, is representative of the first step into standardization and prefabrication practice. It paved the way for many more developments of standardization and prefabrication, not only in timber but also in concrete and steel later. For the ever-expanding British Empire of the 1800s which promoted settler expansion to the far reaches of its colonies, the concept of standardized prefabricated components was vital. It allowed for wall and roof panels to be shipped with the new settlers, thereby providing an instant housing solution without depending on the local natural environment for their building materials and supplies which, in some locations, might not even have existed. In many respects the concept is not too dissimilar to present-day practice where timber panels as a panelized or volumetric system are produced within a factory environment and transported to the site location where panels are incorporated into a conventional building process, or where modular units are assembled to create a modular building and, in some instances, shipped overseas but in the opposite direction to the transactions of the 1800s.

The concept that lies behind full standardization and prefabrication, epitomized by Manning’s cottage design, was not really understood or exploited with the advances of the Industrial Revolution. Indeed, the manufacturing industrialist had more of a focus on an opportunity to manufacture ‘parts’ for a building at worst and ‘building systems’ at best. The thrust that lay behind the very early development of prefabrication was left mostly to the industrialist who naturally focused on producing buildings in the most cost-effective manner. Due to the absence of specific or meaningful architectural design expertise at the critical stage of its development, standardized prefabrication became a much despised approach within the built environment, as many of its effects are recalled by those of the Eastern Bloc countries in Europe and in the UK also. Manufacturing industrialists, however, were certainly alert to the opportunities and occupied the design void to best accommodate their investment on their own terms. The modularity that evolved at that time was more, by default, led by construction systems and assembly techniques originating from within the factory environment as opposed to being driven by architectural design. Consequently, solving the social problems of that time was led by building/construction applications, as opposed to architectural design solutions, where social need formed the principal ingredient as opposed to a desire for aesthetic quality. Architects and designers failed somewhat to recognize the potential of joining up architectural design with manufacturing and assembly processes.

Whilst the UK was already exporting prefabricated ‘flat-pack’ houses to the colonies around the 1800s the epitome of construction systems and prefabrication arrived in a more formal sense with the advent of the Industrial Revolution. This let loose a myriad of building systems and concepts surrounding standardization based on disciplined geometry where new manufacturing processes introduced standardized iron components. Standardization and prefabrication technology continued to be explored as a means for enhancing construction practice, but insufficient design expertise was employed (and by architects especially) to render the enterprise more viable aesthetically. Joseph Paxton, more a gardener than an architect, was instrumental in introducing some fresh design principles and particularly in relation to prefabrication. He identified a perfect solution whereby he satisfied his design brief by fulfilling a building’s commercial obligations in parallel with delivering aesthetically as a natural process.

From Hand-Built to Factory-Made

Here we use ‘construction’ as being the construction processes relating to the built environment (the built environment being the entity for architecture) as opposed to construction processes that might apply to the building of aircraft, motor cars, telephone apparatus or similar complex items.

In order to understand what is meant by conventional forms of construction we need to appreciate firstly the characteristics that make up its ingredients. The term ‘traditional’ would suggest a method of construction employed over many generations which has become the conventional technique for construction dictated essentially by global location and materials available within that given place. For instance, a stone cottage in Wales is synonymous with this environment due to the abundance of natural stone that is easily quarried, just as a timber log cabin relates to the surroundings found in certain parts of America or within the Scandinavian countries, for example. Indeed, there remain numerous examples of traditional timber houses in the city of Vilnius in Lithuania where these historic buildings are still inhabited but nonetheless are located on the very edge of the commercial centre’s more modern architecture.

Joseph Paxton’s Crystal Palace for the Great Exhibition of 1851 highlights an early transition from the more hand-built construction practice to components manufactured in a factory and dispatched to the site for assembly. The Crystal Palace also highlighted a direction in prefabrication as the design brief set by the Building Committee, which included renowned engineers such as Isambard Kingdom Brunel and Robert Stephenson, who specified particular design requirements for a building to demonstrate to the world the status of British industry. By 15 March 1850 designers were invited to prepare and submit their design proposals. Fundamental to their submissions was that their designs had to deliver a building that must be temporary and that it had to be as simple and as economical as possible. Additionally, the building had to be economical to build and completed within the shortest possible time available prior to the grand opening scheduled for 1 May 1851. Architects submitting their designs for this competition were perhaps generally content to follow the aspirations and objectives of their existing aristocratic patrons and clients, but by 1850 Britain was in a new place socially and commercially.

Paxton showed interest in the project following the Building Committee’s rejection of all 245 initial entries. His design represented an excellent interpretation of prefabricated architecture and satisfied the design brief wherein the 10in × 49in size of the glass panes was dictated by the ability of the glass supplier. The cast-iron columns and girders, too, were manufactured within a factory and brought to the site for installation. Paxton’s design demonstrated a clarity in standardization and modularity where the structural iron grid functioned in harmony with the capacity of the glass panels. Paxton’s prefabricated Crystal Palace, then, is a purist vision of prefabricated architecture where factory manufacturing and assembly processes followed a design concept for the building in a purposeful and meaningful manner representing a beauty in its own right.

The dual concept of prefabrication and standardization expresses the attributes of the Industrial Revolution but not all of this form of enterprise provided the built environment with the most satisfactory design aesthetic. Expressions like ‘unitized building’ and ‘building with systems’ did not always convey a positive association with prefabrication and standardization. Indeed, there is evidence which prevails in the countless examples of prefabricated slab constructions within Eastern Europe (Staib et al., 2008) which provides credible reason for prefabricated architecture to be a totally bespoke design specialism only and for prefabrication to do its own thing under the auspices of manufacturing or as an aspect of the construction process (Knapp, 2013).

Prefabrication is not new; it has been with us for many centuries in one form or another, either totally made or aided to some degree through manufacturing and assembly processes. Within the last twenty years, especially with a leap forward in technology and manufacturing possibilities, prefabrication has presented itself as a viable alternative to conventional building methodologies. It is sometimes seen as a panacea for delivering buildings which might not otherwise be possible through conventional practices where the focus is on more building for less cost. Where negative perceptions surrounding prefabrication continue to exist in the current context, they tend to have remained as a mindset resulting from examples of poor design or poor construction or both. This is supported perhaps by the lack of any meaningful evidence to demonstrate that architects were engaged in the early manufacturing processes as part of the architectural design process. A common topic surrounding the prefabrication architecture debate is the absence of commitment from procurement officials to large-volume projects in order to make it sensible and financially viable for off-site manufacturers to engage totally and for architects to adopt a committed holistic approach to design where manufacturing and assembly process are integral to the building’s prefabricated architectural design solution. Joseph Paxton, the gardener, was able to demonstrate over one hundred and fifty years ago a philosophy of simplicity applied to prefabricated architecture; standardization in its purest form has since been taken through numerous iterations of development but not necessarily with laudable distinction in terms of prefabricated architecture being a credible entity in design expertise.

Industrial Design within the Built Environment

Prefabrication is a vast topic covering many aspects of modern living and existence. It embraces a number of sectors and design disciplines, and impacts no less on any one facet due to the natural interaction of them all. Within the scope of prefabrication, however, the built environment is perhaps one entity where it has demonstrated a marked influence and accounts for many unfavourable perceptions held within the UK. The built environment represents the epitome of all our respective cultures by demonstrating the nature and extent of our technological skills, construction techniques and design capabilities. For centuries we applied these skills and techniques to create our housing, schools and hospitals under the umbrella of low-rise or community architecture. As the commercial environments evolved, we created business and financial centres and parks to depict such enterprise, albeit consisting of medium to high-rise buildings. Within the specific discipline of prefabricated architecture then, where technology and evolving construction techniques compete with architecture as a disciplined art, there remains a preference by some to distinguish building as a science and architecture as an art. Moreover, the separation and disconnect which continues to prevail highlights all the more the lack of real commitment of government departments to embrace this new science of building and for architects to embrace manufacturing and assembly as a new art in architecture.

Buildings and their construction techniques remain a constant activity and process in the formation of the built environment since humankind first considered ways and means of providing itself with basic shelter. The various building alternatives employed throughout the ages have varied immensely, as indeed have the array of structural systems adopted, dictated largely by location, climate and the availability of local materials for the building project. Early examples of construction systems highlighted the desire for flexibility, quick easy assembly and dismantling with efficiency, given the nomadic nature of earlier man. The urgency surrounding cost-effectiveness coupled with aspects associated with environmental context and fit only presented themselves as issues much later in the evolution of humans’ awareness of their natural and built environment where a greater focus perhaps lay eventually within settlements. Current demands on the construction process in relation to delivering buildings within a built environment are perhaps more challenging as the quest for more efficient and cost-effective building solutions remains ever-present. In the UK prefabricated housing has dominated a debate since ‘prefabs’ were introduced by the Ministry of Works as a means to overcome the housing shortage following World War Two; negative perceptions which remain ingrained within many have produced a mindset which appears to continue through the generations within the UK.

Terms of Reference

The term ‘built environment’ refers to surroundings shaped by humankind, either by design or default, for the purpose of its own activity and interaction, whether for living, working or recreation. The built environment varies in scale from one’s own personal space to large industrial spaces that may be shared in the performance of a function. The built environment is shaped by the scale of those spaces that are formed by structures referred to as buildings (sometimes architectural gems) and they come in all shapes and sizes, from humans’ first shelters to single buildings and groups of building enclosures, in a considered fashion, and eventually to neighbourhoods and cities. The context for our environment at any one time is, in the first instance, dictated by the total building structures, and secondly by the materials and components employed in their assembly, all of which express an architectural composition. Technology, building materials (whether local or imported), construction processes available in any given location, climate, local culture and context will all add to the mix in producing the form of the built environment, by which the very soul of the place is identified generally and especially by those in occupation. These ingredients, which stand behind every new building project, are depicted by their construction, building processes and methodologies. They are in turn further influenced (and enhanced hopefully) by advancing technology and expertise and a measure of purposeful design where architectural literacy prevails.

Single-storey and multi-storey buildings defining human scale within a built environment.

The human mind can and is expected to absorb many things at one time. The degree to which this function will happen with any measure of efficiency and accuracy is dictated in many respects by the environment within which humankind finds itself. Our environment, whether natural or built, is composed of various elements and scales. Our built environment, being made up of buildings or groups of buildings and structures, forms an immediate reference to our subconscious and our appreciation of the aesthetic represents what we see. The relationship of human scale to that of our environment will act as a major catalyst for the way in which we respond to it. Out of necessity, during some point in our lives, we might find ourselves removed from our own individual environment where the scale of that local vernacular represents all that is precious to us. That is not to suggest, however, that an alternative (whether it consists of the wilds of open exposed countryside or the soul of an inner city) is incorrect as the reliance on our own individual perception of environment will dictate our response to it, whether it is good or bad. The common denominator in all environments is scale and it is to scale that the human mind will relate in the first instance.

Modernist architects of the early twentieth century appear not to have grasped this relationship. Their perception of modularity introduced scale as represented by the large panel of emptiness, devoid of human scale or relationships, as opposed to the modularity of the previous classical order. Whilst there is nothing inappropriate in producing large buildings as such, there is nonetheless discord when the primary elements of that building are of such sizes and dimension as to be so divorced from human meaning and empathy. The early modernist architect might be expected to have had a better understanding of the human scale and the subdivision of elements identified as fractals (Mandelbrot, 1975) as the previous generation of architectural design was founded on classical proportions. Fractal characteristics in architecture relate to a geometry which architects sometimes identify as a ‘module’ for organizing the primary architectural element (Joye, 2007), and this has particular relevance in relation to the modularity of the building’s structural organization. Salingaros and West (1999) refer to the visual balance within substructures and to varying scales provided by the elements displayed within. Composition is derived from a basic mathematical rule on the number and arrangement of sub-elements, which Mandelbrot refers to as fractals, contained within the main structure. Early twentieth-century architects proposed major stylistic changes without perhaps having a full appreciation at that time of how the human eye-to-brain system works. Now there is perhaps a better acceptance of the larger empty panel as architectural style has evolved, with present generations possessing an updated aesthetic, more by default maybe, having become more accustomed and familiar with greater sense of scale. We are perhaps more tolerant in accepting the large empty panel, albeit with minimum interruption necessitated by jointing or connections, as a representation of a clean uncluttered architectural graphic indicative of the minimalist aesthetic, although Salingaros and West (1999) may not agree.

Large panels with subdivision of elements deliver minimalist architecture.

Private house exterior showing empty panel space.

Modular building superstructure completed in factory to 90 per cent and now under final assembly at the site.

Modular office building completed in factory to 90 per cent and now completed.

Architecture is derived from a series of intellectual and physical activities where the design process is led by the architect. Whilst some within the project team may insist on influencing its direction in a particular way for specific reasons, usually cost, the architect’s professional indemnity insurance is a useful tool for generating a sober response on issues surrounding change and adjustment to specification. Architecture is considered to be an art form and is differentiated from other art forms because of its ability to provide function. It is three-dimensional and it allows its internal and external spaces to be occupied usually for a specific purpose. Architecturally then, the use of standardized prefabricated elements and components to accelerate the provision of unitized housing during the twentieth century could be deemed as correct as it performed the function for which it was intended. The result of the prefabricated manufacturing process, therefore, is that which arrives on the site for installation. The ability to classify its aesthetic as a design in architectural language is challenging therefore, as its terms of reference are founded within a language of industrialization and manufacturing which adheres to a set of different rules. Architectural and aesthetic labels did not matter to the municipal authorities facing a chronic housing shortage, nor to the people seeking a place to live, nor indeed to the industrialist whose business it was to stay in business, and there is nothing new in that. The concept surrounding standardized manufactured unitized housing solutions based on prefabricated and modular options is not invalid for what it is intended for, and architecturally that is correct. What is absent, perhaps, is the connection to an aesthetic and a built environment which presents a visual relationship for human consumption. Paxton’s Crystal Palace achieved much of what was desired. Not only did his understanding of architecture and aesthetic instil a new order in design by delivering a building for a specific purpose but, more significantly, a new design discipline which can only be identified as prefabricated and modular architecture: PAMA.

Prefabrication and Design Freedom

Housing and Prefabrication

By the beginning of the twentieth century, Europe was struggling to cope with the massive housing shortage: this continued to the end of World War One and beyond. Given the magnitude of the social housing requirement it could not be satisfied by the traditional trades system as in previous generations. Industrialization was already well established where the large-scale production of goods and products was available at more economical rates, and manufacturing companies and industrialists were always ready to recognize new business opportunities. As purveyors of manufactured products, the industrialists’ primary focus was naturally to produce a product to fit the immediate need and the chronic housing shortage was an ideal candidate. The ingredients for the manufacturing industrialist were perfect and, as a ready-made market evolved throughout most of Europe’s cities, demand continued to expand, coupled with the potential for mass-produced manufacturing as a result. Not all manufacturing industrialists of the period may be identified for their prowess in architectural design but their agility to identify a business opportunity, married to their ability to make profitable products, was their speciality. By the outbreak of World War Two prefabrication had demonstrated itself to be a perfect fit as an evolving set of manufacturing processes in an era of extensive and expanding industrialization.

UNI-SECO

At the end of World War Two, some industrialists and manufacturers transitioned from manufacturing war armaments to manufacturing homes. Names such as SECO, Arcon, Tarran and AIROH became synonymous with manufacturing prefabricated homes throughout the UK.

Typical SECO prefab houses using panelized construction: Excalibur Estate, Catford, London. (Photo by author)

Road view of houses on Excalibur Estate, Catford, London. (Photo by author)

SECO was conceived in 1940 when the UK government was faced with the problem of providing housing for the thousands of workers needed in the new factories. The company’s directors identified then that the traditional methods of building would not be able to provide all the accommodation that was needed quickly enough. In their brochure produced during the war they describe their system as one comprised of wall units (unitized wall panels as assemblies) and components. Whilst seeking to respond to the urgent demand during the war they also demonstrated in their brochure a vision for the time after the hostilities. Reference is made to SECO’s facilities specifically set up to provide training for their outside contractors, of which there were about two hundred companies, to train in their assembly process prior to actually executing a build on the site. There is no reference to ‘construction’ on-site, only assembly. Indeed, it is stated in their brochure that ‘Prefabrication is a matter of degree. It means, simply stated, the factory production of composite building units for dry assembly of the building site’. Whilst the end product always resulted in a volumetric building, the putting together of the parts, components and assemblies was nonetheless an on-site construction process consisting of panel assemblies, components and parts as opposed to a three-dimensional volumetric unit.

Parts, Components and Aesthetics

Literature highlights the attributes and constraints of early prefabrication and the negative perceptions which continue to prevail even today. Some of these criticisms and negatively-held views are well justified and indeed are well founded, given that many of the early examples of prefabricated housing epitomize solely the essence of pure industrialized manufacture rather than any relationship to architectural articulation. Vale (1996) refers to Lethaby who, in 1911, suggested the aim should be to produce housing with the same degree of efficiency as manufacturing a bicycle (a prime example of standardization) in order to satisfy the housing shortage urgency. Similar comparisons by Le Corbusier and Gropius refer to a manufacturing ethos in relation to automobiles and aeroplanes which, in essence, are more orientated toward the mass production associated with the bicycle. Henry Ford in turn took mass production and standardization, under the guise of multiple units, to the next level in manufacturing processes.