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4 Reasons Single-Family Homes Could Be the Next Big Trend in Prefab

Prefabrication and modular construction is relatively new to the United States, adopted only in the past century. Mass timber prefabrication is even newer, gaining U.S. prominence only in the past decade. New imperatives, however, such as the pandemic, technology gains, and environmental, labor and housing crises, are placing prefabricated and modular construction at the forefront. But how will this building approach transcend into single-family housing? Let’s take a look at this emerging trend.

Top Trend in 2021

In a recent survey by Think Wood, respondents chose prefabrication/modular construction as the number three timber trend for 2021. Looking at the single-family home market, the prefabricated and modular homebuilding industry has doubled in size in the past five years, reaching $8 billion annually.

According to Dodge Data & Analytics, prefabrication and modular construction are providing significant improvements to costs, schedule, quality and safety performance, productivity, client satisfaction and waste reduction. Modular techniques can speed up construction by as much as 50 percent and cut costs by 20 percent, according to a 2019 report by McKinsey & Company. It also has the added benefit of being a low-carbon alternative. Design firms and contractors are forecasting expanded use of both approaches as benefits are more widely measured and the industry develops more resources to support innovative applications.

The Benefits of Being Single

According to a report by the Urban Land Institute, single-family homes are expected to outperform other real estate sectors such as commercial, retail, hotel and rentals in 2021. Many factors are driving the single-family home market overall, and the prefabrication trend, in particular:

1) The New Commute

As COVID-19 accelerated and work-from-home took hold in a way that few anticipated, more workers are increasingly able to live anywhere, particularly in secondary markets outside of urban areas that provide more residential living space. Homebuilders are responding to increased demand. Recently released housing start data from the U.S. Census Bureau shows that year-over-year single-family housing starts increased by 15.5% in July 2020. Home sales nationally also remained strong, with home purchase activity up 22% over the same month in 2019. The retreat from city dwelling also spurred the rise of single-family build-to-rent homes. Toll Brothers, a publicly traded homebuilding company, recently announced a $400 million joint venture with a private partner to build single-family home rental communities , targeting Phoenix, Denver, Las Vegas and other fast-growing metro areas.

2) Labor Pains

The increase in productivity gained from prefab and modular construction is especially important for builders given the high demand for, and short supply of, skilled labor. Standardizing and automating construction in a factory setting can also upskill the industry and prepare the trades to efficiently deliver buildings through technologically advanced design, fabrication, logistics and assembly. “During the last recession, many skilled laborers left the construction industry and did not return,” said Thomas Hardiman, Executive Director of the Modular Building Institute. “That, coupled with developers needing to find greater efficiency, made prefabricated buildings more appealing. When things were going well, developers and general contractors may not have felt the pain or need to change. Now they do, and there’s no turning back.”

3) The Digital Revolution

Another driver of residential prefab and modular growth is technology. The industry is now embracing digital tools like 3D modeling, building information modeling (BIM) and computer numeric control (CNC) machines, making prefabrication and modular construction more common. As James Timberlake, FAIA, says in the foreword of Ryan Smith’s book, Prefab Architecture: A Guide to Modular Design and Construction, “We are now capable of sending a fully visualized, and virtually formed, model to a production line, bypassing the document interpretation phase, with all of its back and forth checking, redrawing and margin for additional errors and omissions, ultimately improving the quality of the final product.”

4) Seeing Green

In addition to technology advancements, pandemic-driven decision making and labor productivity gains, environmental views are changing regarding construction waste, supply chain, building materials reuse and carbon footprint. Wood construction, particularly prefabricated components, can help designers to balance cost objectives, function and environmental impact. “Integration modeling, the backbone of off-site fabrication and manufacturing, leans the product supply chain, helps architects and contractors manage the number of materials needed and allows for a positive repurposing of the leftover materials, added Timberlake. “Further, off-site assembly offers the promise of disassembly and re-use.”

Preferred and prefab-ulous.

As these benefits add up to meet the changing demands of homeowners, architects and builders that employ prefab are seeing substantial increases in contracts, some up as much as 50 percent in 2020. Here are some notable prefab and modular examples making their mark in an expanding industry.

CLT in Seattle

CLT is one of the most common prefabricated building materials making its way into residential construction. 19 Besides the environmental benefits of CLT, most of its appeal stems from the time saved during the framing process. The panels are prefabricated and delivered to the job site already cut to size and ready for installation. Very few adjustments, if any, need to be made on-site, assuming the original plan was correct and followed properly.

Architect and mass timber pioneer Susan Jones of atelierjones oversaw the building of one of the first CLT single-family residences in 2015 — her home in Seattle, WA. Situated on a small, 2,000-square-foot triangular lot across from an alley, the 1,500 square-foot CLT Home was built to Passive House standards. It was constructed from prefabricated CLT panels and clad in Shou sugi ban, a technique where wood is treated with fire, leaving a charred finish that can protect it for years.

Photo credit: Lara Swimmer Photography

The panels were routed using standard CNC technology, and the floors and walls were designed to fit within 16 panels of 8’ x 40’. Left almost raw with a light whitewash, the walls of CLT are exposed, interior trim is kept to a minimum, and utilities are hidden in a central service core. “The acoustics are incredibly rich, there’s a beautiful tone,” said Jones.

Photo credit: Lara Swimmer Photography

Susan Jones

Principal, Atelier Jones

CLT Home

You can still smell a little bit of pine scent in the air, and the way it captures the light is absolutely magical.”

Totally Turnkey Construction

Turnkey housing is another growing trend in the prefab/modular market. Los Angeles-based CLT Architecture is a full-service architectural studio and contractor who specializes in designing, engineering and building CLT single-family homes, including luxury models. According to the firm, the precision of prefabrication enables quick assembly, averaging only one to three days on the construction site and 6-10% savings when compared to traditional methods.

The multi-layered CLT also allows the production of panels with various applications: visual, acoustic and fireproof, and makes it easier to achieve passive environmental standards. From a performance perspective, panels have the ability to store heat in the winter and protect the house from overheating in the summer. They can also be used to produce structures of unusual shapes, allowing for innovation in design.

Photo credit: CLT Architecture

Photo credit: CLT Architecture

Right-Size Housing

What if your starter home could grow along with you and your family? This is the vision of Pittsburgh-based start-up, Module. The company sees right-sized houses as one way to help address the problem of affordability. Units start as small as 500 square feet, which keeps the initial cost down, but if the owners ever need more space in the future, the roof can be removed and another box can be set in place in a day to create an additional floor. These module homes are built in a factory using wood frame modular construction. Building in a controlled environment means the homes are more precisely constructed and are 25-40% quicker to build than a traditional home. Thirteen models are available to choose from with 1-3 bedroom options. The homes are built to be Zero Energy ready.

Photo credit: Module

Photo credit: Module

The Greenest House on the Block

Carbon-friendly, net-zero goals are another driver of prefab and modular housing, with a number of new start-ups popping up sustainable “eco homes” around the world. Plant Prefab is a spin-off from LivingHomes, one of the first and most well-established prefab companies in the US. The company focuses on the urban infill market and hopes to make it easier, cheaper and faster for customers to build eco-friendly and high-quality homes in cities. A smaller carbon footprint is standard with all Plant Prefab-built homes, and the Koto line wants to cut that down even further.

Photo credit: Plant Prefab

The Koto models are built to be net-zero and include the standard sustainable bells and whistles: Super-efficient heating and cooling systems, low-flow fixtures, recycled insulation, LED lighting, smart energy monitoring systems, and more.

Using as much carbon-sequestering wood in construction as possible, Koto LivingHomes are factory-built using the patented Plant Building System, an efficiency-boosting hybrid method that combines modular units with panelized components, or “Plant Panels” that include integrated plumbing, electrical, and other necessary infrastructure. In January 2021, Plant Prefab launched its first-ever collection of passive homes in collaboration with Richard Pedranti Architect (RPA).

Photo credit: Plant Prefab

Rent the Backyard

Anderson Anderson Architecture has been designing prefabricated modular building systems for many years, including residential, school and commercial applications. Anderson Anderson believes that the CLT method has many advantages, including inherent strength, fire-resistance and sound isolation, in concert with robust finish surfaces and absence of cavity wall concerns. In partnership with start-up Rent the Backyard, their newest venture includes free-standing modular “accessory dwelling units” (ADUs). The structures are prefabricated off site, then lifted by crane into place in a backyard or other location.

Anderson Anderson, Rent the Backyard

Photo credit: John Arbucle

Units are constructed in two months and installed in as little as two weeks. The entire structural module and primary enclosure is constructed with just six massive, cross-laminated timber panels, including four wall panels, one floor panel and one roof panel.

The project aims to densify typical single-family home neighborhoods, bringing affordable housing into the community and providing rental income for homeowners. Affordable housing production has been a big focus of California government programs and planning efforts, with zoning code revisions allowing ADUs on single-family sites throughout the state. This mass timber version is the first of its kind and offers a wide range of design options. Pricing starts at $185,000.

Anderson Anderson, Rent the Backyard

Photo credit: John Arbucle

Looking ahead, the prefab and modular housing market will be one to watch as new companies and techniques continue to emerge. Stay tuned for more on this growing trend on Think Wood’s What’s New page.