Prefabrication: The Growing Need for Supply Chain Collaboration
Author: Jen Taylor, Diana Fisler and Nolan Browne
Prefabricated construction systems have the potential to reduce building energy demand by up to 82% (Pittau) compared to traditional on-site builds by creating buildings with air-tight envelopes, high insulation values, triple pane windows, and ERVs for air circulation, as well as by including features such as solar panels and smart thermostats. This is not to say that traditional on-site builds cannot also have these features; but the repetition and standardization of prefab enables greater cost-efficiency, precision, and quality control. For example, the window/wall interface is a common place for an envelope to lose its air-tightness if not carefully installed and well sealed. Repeatable prefab processes generally perform more reliable sealing in comparison to a human hand on a caffeine buzz and a tight schedule.
Advanced building quality is not the only characteristic of prefabrication that can have a strong environmental impact. For example, over 500 million tons of construction and demolition debris are produced annually – in the US alone. A prefab manufacturer, however, can produce panels for an entire building in a controlled factory environment with as little as a few rubbish barrels of waste in the factory and next to no waste on-site. Streamlining this process and popularizing prefabrication could greatly reduce the amount of timber, composites, and other raw materials consumed by new real estate developments.
Sanford Contracting and Window Pre-Installation
On July 1st 2021, ADL Ventures was pleased to have the opportunity to meet with Tom Sanford, owner of Sanford Contracting Inc. in North Billerica, MA. Sanford has been advancing prefabrication for the past 47 years and has an impressive panelized building portfolio, including Foxwoods Hotel and Casino and Assembly Row at Assembly Square. Tom graciously took the time to sit down with us and talk about the challenges he and other manufacturers are facing in the field.
Although the current method for most manufacturers involves leaving a rough opening for the window in the panel, assembling the building, and then using commercial construction equipment to install the window from the outside, Sanford Contracting takes a different approach. The company partners with JK Glass to install windows into their panels at the North Billerica plant during the manufacturing process rather than at their construction sites. Reducing overall costs, improving panel quality, and saving time: this partnership is a great example of how to improve the supply chain.
These types of partnerships are not uncommon, but this one is particularly valuable. First and foremost, it’s safer: installing windows at the plant means fewer installers hanging off the sides of buildings. It also means less equipment and manpower required since cranes and their operators no longer need to be accounted for, reducing total installation costs. Equipment aside, the labor rate per worker in a shop is typically lower than in the field (not to mention the time savings overall). Lastly, it is also possible that the window may break or warp during installation, especially when exposed to different outdoor environments. The controlled shop environment leads to more precise window installation and in turn better insulation, sealant, and a higher energy savings rate.
Yet, many prefab manufacturers are hesitant to preinstall windows. To make it from the plant to the building construction site the panels have to travel on a truck, often enduring bumpy roads shared with unpredictable drivers. The possible repercussions of a pre-installed window breaking are enough to make most manufacturers shy away from preinstallation altogether.
Sanford Contracting, however, ventured to test these concerns in practice. In the late 90s they loaded panels onto a truck with preinstalled windows and drove for hours over the roughest roads they could find, and as may be a surprise to other prefab manufacturers… no windows or seals were broken.
Since that fruitful learning experience, they continued to pre-install windows into their panels, initiating their partnership with JK Glass in 2008. In the years since, only three sets of windows have broken post-installation. During the first instance, vandals who broke into the plant threw rocks at the installed windows of panels waiting for shipment. In the second instance, a panel was dropped by a malfunctioning crane. Only in the last instance was the window breakage travel-related, when another driver rear-ended the truck carrying the panels. The smashing success of the Sanford Contracting and JK Glass partnership demonstrates that collaboration within the supply chain can be a key to both maximizing profits and delivering a better product.
A panel in the midst of the building process sits in the controlled plant environment as employees come around one group at a time to complete their designated step in the panel building process.
A Sanford Contracting employee moves from panel to panel sealing the windows, one of the final steps in the process.
The Big Picture
The hesitancy of manufacturers to preinstall windows reveals a much larger issue that is a massive threat to the advancement of prefabrication in the United States. America has thus far failed to leverage best practices and lightning bolt ideas across its fabricator network. The burden of ideating and/or testing new construction practices lies solely on the fabricators themselves — but fabricators today must adopt all of the risk and only some of the benefit. As such, there is a desperate need for the whole construction supply chain to step up and share the burden of innovating by sharing and pooling the best ideas and using both private and government resources to popularize and stand behind these ideas.
This is where the Advanced Building Construction Collaborative (ABC Collaborative) comes into play. RMI and its team (consisting of ADL Ventures, AEA, PHIUS, and VEIC) is launching the ABC Collaborative with the support of DOE to work with incumbent and emergent stakeholders to help accelerate the uptake of advanced building construction (ABC) methods in service of energy efficiency and decarbonization. The ABC Collaborative serves as a hub for cooperation and market facilitation, wherein building sector stakeholders can come together to identify roadblocks, drive mutually beneficial solutions, and implement the widespread adoption of ABC for the good of the construction industry and the planet.