Fabricating Architecture - Where Do Architects Stand?
Dr. William Hogan-O'Neill - Author, Chartered Architect, and Coach
Architect Knowhow, July 07, 2022
Over twenty years ago I became aware of some new advances in off-site manufacturing processes and how they might apply to the architectural design of certain building types. Off-Site Manufacturing was the overall umbrella term used at the time. There were a variety of different systems originating from the factory environment being applied to the on-site construction processes but there was no distinct system which dominated the market as the outright champion or absolute substitute for conventional construction.
In around 2004, my architects practice was commissioned to design a school building consisting of a number of teaching spaces, resource spaces and toilet facilities. It was not a large project, and neither was it our first commission with this client, as we had previously completed a number of other school projects for them in the past. It was, as all projects are a very valued project and one which created the usual excitement. At the time of this school commission, we had built up a good rapport and understanding with our client. I remained alert to the fact that money was tight, and time was of the essence in delivering school places. The client on the other hand was satisfied we could deliver a pragmatic solution where architectural design formed an essential part of our service for the available budget.
In parallel with our professional activities, I had become more enthused by what off-site manufacturing had to offer in terms of providing an alternative approach to architectural design. I had already carried out some research and investigations surrounding off-site manufacturing alternatives as an option to traditional/conventional construction methods for delivering efficient buildings. I believed then, that there was a real alternative solution that would be more time and cost-efficient for our local authority client. I continue to hold that view.
A build-over design solution for school project negates the need to occupy valuable playing space at ground level. This design solution was made possible by employing Prefabricated and Modular Architecture (PAMA) where conventional construction works would be too intrusive, requiring heaving engineering and consequently expensive.
My objective was to demonstrate to the client that by adopting an off-site manufacture approach we could deliver the urgent classrooms in approximately five months as opposed to the projected eleven months if we were to continue with the conventional construction approach. Naturally the client was enthusiastic about being able to deliver additional classroom much sooner and potentially with less cost. However, from the contractor’s position, the notion of anything which reduced project aspects, and thereby his profits away from the main contractor package, was considered treason. Our design meetings were interesting to say the least, but the notion of introducing anything other than a conventional build approach for the project was not met with any enthusiasm by the contractor.
The final project presentation made to the client was that both the traditional construction and the off-site manufacturing alternative option were evaluated. However, the main contractor maintained his traditional/conventional construction approach for the project would be less cost-prohibitive and there would be no time savings to be achieved either. I was not convinced even then, that his evaluation of the alternative proposal was accurate. I was mindful, however, that his ability or willingness to enter into a collaboration with an off-site manufacturer was absent. I was aware too, that a significant element of the project would essentially consist of a specialist sub-contractor package and that of course meant a significant reduction in his overall project profit. The client decided to proceed with the project based on the ‘cheaper’ option which in itself clarified priorities to me whereby there was more time than money when it came to delivering teaching spaces.
Fortunately, with a constant perseverance and exploring the architectural design process specific for the off-site manufacturing process, we arrived at a point where our practice was able to demonstrate the real viability associated with what is essentially assembling and manufacturing buildings in a factory as opposed to assembling buildings on the site and all the hoo-ha that entails, which incidentally is another topic entirely. We applied this design approach for a number of different projects consisting of housing, schools and sports facilities for example.
A large primary school building in South London is one of a number of additional projects completed in Panelisation
Moreover, certain manufacturing companies became more alert to the potential business opportunities within the building industry whereby a variety of systems began to flood the market and terms such as ‘Off-site Manufacturing’, ‘Modern Methods of Construction’, ‘Modular Buildings’ to ‘Modular Construction’ become the norm. Naturally all that brought total confusion in identifying what term meant exactly, and for which type of building. The industry arrived at a point in time where a total muddle prevailed. In some respects that remains the case today although some degree of clarity does exist for certain specific systems and how they facilitate building procurement for the client.
Evolving Trends In Housing
Examining Prefabricated and Modular Architecture in relation to conventional architectural design can be a very emotive subject for many within the construction industry and also in the architectural design fraternity. When exploring the attributes and constraints associated with prefabricated/ modular buildings through panelisation or modularization, the discussion usually comes first to housing. This in itself conjures up past images of flimsy structures of past generates and in many ways that would be correct.
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, approximately 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.
A 136-metre-high modular apartment building was completed at 101 George Street Croydon
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.
Many architects appeared to be disinterested in this new alternative design approach. The notion of creating a unique design discipline where architectural design principles were applied as a natural part of the manufacturing process for delivering architectural design solutions was anathema at worst or nuisance at best. Needless to say, the void in architectural design and the specialist design skills necessary associated with ‘Design for Manufacture and Assembly (DfMA) was filled by the manufacturers themselves as opposed to architects taking a lead role in this evolving enterprise.
Up to the recent past, the limitation attached to modular buildings surrounded building height restrictions limited to five and six-storey height and was deemed to be the optimum for prefabricated or modular buildings. That however has since been negated by innovative engineering which has been applied to the architectural design process. In 2020 the tallest modular apartment building was underway in the London Borough of Croydon UK which is a landmark statement for the sceptics. The project delivery time was 39 months from initial concept to handover employing a factory assembled 3- a dimensional volumetric modular solution where the structural engineering for the 44 (136 metres) and 38-storey towers was catered for within the structure of the modular units; world-leading engineering design. It is also claimed a 40% reduction in embodied carbon was achieved compared to employing conventional construction methods.
Perceptions Surrounding Factory Buildings
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 current construction industry, one fraternity will maintain that prefabrication, or any product derived from the off-site manufacturing (OSM) process, is 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 and with those cost savings, (which is an advance from my project back in 2004) 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. Not much change there!
Certain manufacturing companies are always alert to the potential business opportunities within the building industry and prefabrication and modularisation is no different. Over the past fifteen years especially, a variety of new factory-made systems began to flood (cash-in on) the market. I mentioned previously terms such as 'Off-site Manufacturing', 'Modern Methods of Construction', 'Modular Buildings' and 'Modular Construction', 'Panelisation' and 'Modularisation' become the norm. With all that of course brought further muddle but with even greater confusion as to what these terms actually meant and for what type of building. As all of this made-up terminology became more in vogue, the manufacturing industry brought even more chaos upon itself, and architects were not part of the conversation.
For many centuries, however, methods employed in delivering buildings have been monopolised 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. There was a call from the 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 industrialisation. Since then and particularly within the last two years a number of well-known major players in the Modular Buildings market such as Caledonian, F1 Modular and Urban Splash have been forced into administration. Whilst the recent pandemic may be a contributing factor, the willingness for central and local government departments to commit to large-scale projects continues to be absent. Only larger-scale projects allow prefabricated and modular buildings to be designed and manufactured that are financially viable because the economy of scale is the vital ingredient in the mix. Providing projects of fifty to a hundred units is no good to a company that is set up and geared up to produce thousands of units.
Specialist Architectural Design
Current thinking within certain design fraternities, too, often see 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 and modularisation are one.
These design considerations are likely to include the following: design where the 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, the 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. This is precisely where architects tend to divorce themselves from the prefabricated and modular architecture design process. We tend to allow the architectural design to be influenced by the manufacturing and assembly process and accept the architecture that results therefrom. I continue to wonder at what point in time will architects take charge and own the entire design for the manufacturing and assembly (DfMA) process.
The school project back in 2004 that I referred to earlier where their contractor convinced the client to proceed with convention construction did not go to his plan. It was delivered four months over his eleventh-month delivery and, was £45,000 more expensive which today would equate to around £70,000.
A Passionate Tale
By now you have probably guessed that I have been passionate about this particular topic for a considerable amount of time. In fact, I wrote a book about it! Prefabricated and Modular Architecture – Aligning Design with Manufacture and Assembly is the result. Further information is available at
The 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 recognise as a dedicated design and manufacturing specialism.
Three Dimensional Volumetric Modular Unit lifted up and fixed into position as an assemblage to form a completed Modular Building - Location Lewisham South London
As a practising architect eventually specialising in this specific field of architectural design also, I managed to bring some clarity to the architectural design and procurement process by identifying each of our specific projects for what they were in actuality. In essence, our projects were identified under two primary umbrella types namely, Panelisation and Modularisation and the numerous variations connected to the same. The reasoning behind deciding which one was suitable was always dictated by the attributes and constraints associated with each project site which resulted from our site analysis. All was under control and our clients knew what they were getting for their money and why.
Out of the blue in late 2017 I received an email from Lucy, a Commissioning Editor with The Crowood Press, a UK Publisher. She was inquiring about my interest in a new book idea she had. Referring to my experience in this specific topic, which she had researched apparently, she mentioned she is seeking to commission a book on 'Pre-Fabricated Architecture Design'. Frankly, I considered this to be yet another scam and deleted the email accordingly. Two weeks later, I received a further email from Lucy in follow-up on whether I had given the matter some thought.
Curiosity got the better of me, and I called her. I met with Lucy at the RIBA a week later, had lunch there, discussed the book idea, discussed a contract, said goodbye, and had a contract signed within a month. The rest as they say is history but writing this book has provided me with an additional platform which I have continued with ever since. Tasked with the responsibility of writing a book on a passion of mine was both exciting and scary. Exciting because I had a platform with which to clarify some of the muddle that prevailed and scary because I was not really sure I was up to the task, but I never turn away a challenge!
This book is the result of many years in architectural practice and with a mission to fostering a viable alternative to the conventional construction process. It represents a twenty-year commitment to employing architectural design principles to an established manufacturing process which tends to have mindset on assembly efficiency alone.
People who have read it tell me they enjoyed it and here are some more Amazon Reviews -
- "Hugely informative read for any student, architect or construction professional"
- “Very well researched and informative read”
- “A must-to-read book for the Architecture, Engineering and Design Professionals and Students”
Completed Modular Building - Location Lewisham South London