Offsite Architecture

Constructing the future

Ryan E. Smith, John D. Quale, Ryan E. Smith, John D. Quale

• Editorial: Routledge
• Año: 2017
• ISBN:
  9781317588818
• Edición: 1
• Categoría: Architecture
• Categoría: Architecture General

Architects have been intrigued by prefabricated construction since the early twentieth century. Recent advances in design, engineering and manufacturing processes have led to a significant expansion in the use of pre-assembled components, which are fitted to finished structures on site. Collectively, such processes are becoming known as "offsite construction."

A ground-breaking text, Offsite Architecture establishes the current – and future – state of thinking in this field. A range of the most highly regarded thinkers and practitioners from around the globe share their ideas and practical findings on offsite prefabrication, examining theory and practice, opportunities and challenges, successes and failures.

A timely response to the growing interest in this method, the book provides the fundamental basis for a critical, reflective approach to offsite architecture. Contributions from both academics and professionals make Offsite Architecture required reading for practitioners as well as students taking courses in architecture, prefabrication, construction and engineering.

Part B
Offsite practices

Chapter 6

Offsite construction industry meta-analysis

Industry survey results

Talbot Rice and Ryan E. Smith

Introduction

Instruments of labor not only supply a standard of the degree of development which human labor has attained, but they are also indicators of the social conditions under which that labor is carried on.

– Karl Marx, Capital Vol.1

There are a series of historical events that have propelled the development of prefabrication. Examples include the climaxed development of cast iron in the Crystal Palace built in 1851; prefabricated houses driven by the California Gold Rush in 1848; precut houses, or mail-order houses, developed in the early 1900s; and precast concrete, seen in developments from Thomas Edison in 1908. Post-World War I, parts of Europe, such as Great Britain, Germany, France, and Sweden, experienced a heavy decline in the supply of skilled labor and were thus motivated to explore innovative methods of construction. On the contrary, the US was experiencing an all-time high in construction production. So, the use of prefabrication and the need for construction innovation was not in demand. The historical economic motivation to further develop and adopt offsite methods of construction is further outlined in canonical prefabrication texts.¹

Today, offsite construction is widely adopted in the US and more present than in any period in history. In the National Institute of Building Sciences 2014 Off-Site Construction Industry Survey, it is reported that 93 percent of all construction industry respondents are using prefabrication to some level.² Some reasons for adopting prefabricated practices today are explained by James Timberlake in the foreword of Prefab Architecture.³ First, other manufacturing industries have changed the way their products and services are delivered (i.e. the automobile, shipbuilding, and aerospace industries). Second, the critical difference in these production industries that makes factory production viable is an integrated supply chain. Third, the environmental ethic of the construction and architecture industries has begun to change. This is especially true since onsite construction has been estimated to waste up to 40 percent of all new products brought to site.⁴

Figure 6.1
Demand of construction versus supply of skilled labor, 2005–2016 (Credit: Cumming Corporation)

Beyond the reasons above, there are additional causes that contribute to the growth in the use of prefabrication. One of these reasons is the rise in construction demand and a shortage of skilled labor. In Figure 6.1, it is demonstrated that the demand of construction has increased since the recession of 2008, yet the supply of skilled labor to meet that demand has not followed suit. Another reason there has been a rise in the use of prefabrication can be attributed to the development and implementation of BIM, or Building Information Modeling.⁵ BIM is used widely in the construction industry to more efficiently plan, design, construct, and manage buildings and infrastructure. The offsite industry is taking advantage of BIM for design to manufacturing interoperability. As such, the prefabrication of construction components and assemblies naturally go hand-in-hand with the benefits of using BIM.

While the emergence of BIM has stimulated the popularity of prefabrication methods, the industry remains reluctant to adopt methods of prefabrication. One explanation is that there is little substantial quantifiable data to support the benefits of prefabrication in construction delivery. To enumerate the claims of prefabrication performance (i.e. cost, schedule, safety, productivity, etc.), there have been efforts to conduct industry-wide surveys and reports. Three recent surveys will be evaluated in this chapter: Prefabrication and Modularization: Increasing Productivity in the Construction Industry by McGraw-Hill Construction (2011); Prefabrication and Modularization in Construction 2013 Survey Results by FMI; and the Report of the Results of the 2014 Off-Site Construction Industry Survey by the National Institute of Building Sciences Off-Site Construction Council. All three publications have their own unique findings, many of which are reinforcing. This chapter is a meta-analysis of the three surveys and provides a summary of each survey and the comparative overlaps.

Surveys

Over the past half-decade, companies and organizations have developed surveys and disseminated resultant reports on the use and practice of offsite construction. The main purpose of these surveys is to identify the key performance indicators associated with offsite construction. The surveys identify barriers and substantiate claims for the industry. The following are summaries of the three surveys in chronological order.

Prefabrication and Modularization: Increasing Productivity in the Construction Industry (2011) McGraw-Hill Construction

Intent

The SmartMarket Report team at McGraw-Hill Construction developed this report in 2011. The aim of the report is to provide industry views on prefabrication and modularization and their impact on the construction industry broadly.

Method

This report is the result of an online survey of 809 respondents from across the AEC profession. The survey quantifies the impact of offsite construction on project schedules, costs, safety, quality, and waste reduction. The study also involved 15 in-depth qualitative interviews with owners/developers.

Key findings

Table 6.1 shows the key findings from the 2011 McGraw-Hill Construction report.

Table 6.1
Key findings from the 2011 McGraw-Hill Construction report

Schedule	66% reported that project schedules are decreased. 35% responded that the reduction is by four weeks or more.
Cost	65% reported that project budgets are decreased. 41% responded that the reduction is by 6% savings or more.
Waste	77% reported that construction site waste is decreased. 44% responded that the reduction is by 5% or more.
Usage	63% of those that responded have been using prefabrication methods for five years or more. 85% of respondents are using prefabrication today (90% of engineers, 84% of contractors, and 76% of architects).
	Only 37% have been using prefabrication at a high or very high level (more than 50% of projects).
	Within the building, respondents indicated that prefabrication most often occurs in the building superstructure (27%), MEP systems (21%), and exterior walls (20%).
	To use prefabrication methods, the following are parameters for consideration: job site accessibility (58%), number of building stories (53%), type of exterior (52%).
	Prefabrication is used in 47% of small construction firms, in 28% of medium-sized firms, and in 25% of large firms.
	Prefabrication is used by 22% of small A/E firms, 32% of medium firms, and 46% of large firms.
Barriers	The primary reason that the respondents indicated why they are not utilizing prefabrication methods on some or all of their projects is that the architect did not design them into their projects. (Architects claim that the resistance is from the owners.)
Drivers	The current drivers for utilizing prefabrication methods are as follows: 77% to improve productivity; 66% as a competitive advantage; 51% because it generates greater return on investment; 39% because of owner/client demand.
	34% of respondents indicated that using prefabrication leads to improved site safety, while 56% of respondents indicated that prefabrication is just as safe.
Markets served	The five sectors using prefabrication in over 40% of projects are: healthcare (49%), higher education (42%), manufacturing (42%), low-rise office (40%), and public (40%).

Prefabrication and Modularization in Construction 2013 Survey Results (2013) FMI

Intent

The authors of this study believe that the industry is following an impactful trend of adopting prefabrication techniques, sometimes fabrication facilities, into their design and construction practices. The trends identified as driving forces to adopt prefabrication techniques include:

• the constant pressure to lower prices;

• the need to achieve a competitive edge in markets increasingly calling for the use of prefabrication and modularization;

• the lack of, or impending lack of, skilled construction labor;

• the use of BIM, allowing greater coordination of design with construction;

• the need to increase productivity.

Two of the primary drivers of the survey were to identify the barriers to adopting a prefabrication facility and the extent to which prefabrication has contributed to a return on investment.

Method

The survey was sent out to contractors across the field of construction. This included GCs, CMs, MEP contractors, HVAC contractors, and so on. The questions were sent out through email and regular mail to these selected lists.

Key findings

Table 6.2 shows the key findings from the 2013 FMI report.

Usage

48% of MEP contractors accomplished m...