Speed in construction has always been highly sought after. Speed means that buildings go up faster, and budgets are likely to stay lower. The quicker an owner can get a return on investment the better (e.g. speed to market with a new product or increased rental income). For those reasons alone, prefab architecture and Lean Constructing are two concepts that loom large in the future of building.
According to Mike Bedell of Balfour Beatty Construction, who is considered a pioneer in the field of prefab and modular design, “Prefab achieves the quality our owners seek, while saving manpower and time and making our work safer.”
Lean Construction is a concept derived from the principles of Lean Production championed by the architects behind the Toyota Production System, a phenomenon that altered the landscape of the once American-dominated automotive industry. The Toyota system relies on a principle known as “Kaizen,” through which projects and process are optimized to reduce waste through the process of continuous improvement. By drawing from these concepts of Lean Production, Lean Construction looks to eliminate construction waste and inefficiency a project management process that is “structured, controlled, and improved in pursuit of maximizing value to owners and workflow reliability on construction sites.”
Recession-Driven Changes in Construction
During the 2010 recession, many construction workers lost their jobs and architects couldn’t find clients. Customers and owners with money took advantage of marketplace conditions to leverage most advantageous deals possible. With money in short supply, many long-term members of the design and construction industries left for more reliable fields or simply retired.
The building industry as a whole lost a great deal of its skilled personnel and support structure. As construction demand has returned, the capacity to support that demand has not. Demographics have shifted as a fewer and fewer youths seek to acquire trade skills in the 21st century, instead opting to pursue more lucrative careers in technology, medicine, or other fields.
Facing revitalized demand and a labor shortage, prefabricated architecture has never been more sought after, as builders and designers increasingly view the future of construction being heavily reliant on manufactured buildings and prefabricated components.
Similarly, Lean Construction methodologies are challenging the status quo of both large and small-scale projects being completed over-budget and past deadline. The construction industry, still bearing fresh scars from the last economic downturn, today views the improvement of manufacturing processes and the elimination waste as priorities of the highest order.
Hospitals Represent as an Ideal Case Study
As an example of how prefabricated materials are impacting construction, consider the fact that hospitals, which are making extensive use of prefab technology, can now go up in weeks instead of months. Hospitals are an ideal use case for prefabricated architecture as they typically feature a similar number of rooms and designs repeated on floor after floor. Because these designs can be prefabricated relatively easily, construction time is quicker and the process, from design to assembly, is more efficient.
Even absent the use of prefab materials, the Sutter Health Eden Medical Center (SHEMC) in Castro Valley, California offers a hugely successful example of the benefits of Lean Construction and project delivery methodologies. The SHEMC project came in under budget, “opened for business 6 weeks ahead of the “first patient” milestone,” and boasted an impressive “time on task for the major trades (of) 74%, which was far above an average 30% to 50% range found in previous studies.”
Enhanced Speed of Production
Across the Atlantic in Uckfield, England, a 2012 flood ravaged large parts of the community, including the local McDonald’s. Though at one point the old one was awash in six feet of water, it was back in business just two weeks later thanks to modular construction.
Today, the Portakabin Group has completed over 200 construction projects for McDonald’s in the UK, using prefab and lean manufacturing techniques to build new structures with astounding efficiency.
“Constructed off-site in a quality-controlled factory environment, the restaurant was craned onto prepared foundations in just a few hours. It was delivered complete with all catering equipment, signage, glazing, heating, plumbing, ventilation, ceramic finishes, joinery and internal walls pre-installed. Less than two weeks later, the restaurant was open for business.”
While Portakabin does not specifically cite Lean Construction and project delivery techniques, the concept of off-site construction is inherently sustainable. A prefab-integrated approach enables the use of more sustainable and recycled materials, in addition to facilitating a more controlled environment through much of the construction can take place.
Many modular components can be constructed entirely from recycled materials, meaning far fewer natural resources need to be used in the building process. The buildings go up quickly, resulting in less energy being used for construction. In fact, studies have shown that when prefabs are used, energy consumption is reduced by about 67% compared to a normal worksite.
Manufactured buildings typically feature very environmentally-friendly properties as they typically use the most efficient windows, renewable energy sources such as solar panels, and energy-efficient water heaters and geothermal systems. These buildings also tend to require less maintenance, again meaning less energy usage.
One of the core tenets of Lean Production, and thus of the Lean Construction, is related to the total elimination of waste. Advocates of Lean Construction suggest that projects should produce only what is necessary with the minimum manpower. An increase of efficiency is obtained when waste trends towards zero. By definition a reduction of waste improves environmental efficiency.
Aligning Prefab Architecture & Lean Construction
The demand for enhanced energy efficiency, flexibility and durability in construction means that prefab architecture, in conjunction with Lean Construction principles, will likely be hallmarks of building in the decades to come. However, the two principles should not exist in a vacuum independent of one another. In his paper for the 23rd Annual Conference of the International Group for Lean Construction, Michael Hermes advocated for the use of prefabrication as part of Lean Construction, citing several benefits that align with Lean Construction’s objective of continuous improvement. Time and cost savings, a reduction in the frequency of errors, and improved worker safety achieved through the use of standardized, prefab materials, offer “further optimization opportunities to live the Kaizen principle.”