How Prefab Construction Addresses Traditional Problems

How Prefab Construction Addresses Problems With Traditional Construction

By Tommy O’Shaughnessy, the owner of Rent a Backyard

The traditional construction industry comes with an incredibly high environmental cost; experts estimate that building new homes and buildings is responsible for 10% of total global emissions, while operating, heating, and cooling these energy inefficient buildings adds another 27% of global emissions on top of that. All told, that means that constructing and operating conventional buildings is responsible for nearly 40% of total global emissions. 

That’s a massive burden of responsibility for the construction industry, and there’s really only one path towards lowering those numbers. Demand isn’t going anywhere; if anything, it’s projected to steadily increase. Because of population growth, square footage the size of New York City will have to be constructed each month until at least 2060. It’s not practical to construct less—but it is practical to change how we construct. 

Enter Prefab Construction

Prefab construction addresses many weaknesses of conventional construction—it consumes fewer resources and produces less waste, has a dramatically smaller carbon footprint, and produces structures that are radically more sustainable.

Prefab construction is booming in Europe, where housing shortages and strict green building initiatives sparked the fledgling industry. Originally envisioned as a quick relief response to natural disasters, prefab homes are now widely popular after German, Swiss, and Scandinavian designers produced elegant, energy-efficient homes that, in many cases, can be assembled in a single day.

As the U.S. confronts its own housing shortage, as well as the true environmental cost of its construction industry, prefab homes offer a ready-made solution to both problems.

But there are real obstacles to its widespread adoption, including regulatory challenges and homeowner preferences. Let’s touch on what exactly makes traditional construction so environmentally unsound, and why prefab construction offers such an enticing alternative.

The True Costs of Traditional Construction

One of the main reasons that traditional construction is so bad for the environment is because it uses so much concrete.

Concrete is a mixture of component materials like sand and rock (often locally sourced) that’s mixed with cement and then left to dry. Manufacturing cement involves firing clay, limestone, and other materials in a kiln, a chemical reaction which produces nearly a pound of carbon dioxide for every pound of cement; the concrete industry alone produces 8% of annual global emissions. 

The largest concrete companies have already taken steps to reduce their carbon emissions, but progress has been slow and incremental. For example, one industry leader has reduced their emissions by 25% since 1990, while another has a goal of a 35% reduction by 2030. That’s real progress, it’s a far cry from the ideal net-zero target. 

While there is a growing green concrete industry that offers up to 40% reduction in emissions, traditional construction’s heavy demand for concrete projects to be a huge driver of global emissions, especially as residential construction ramps up in the coming decades. 

And then there’s the waste. Traditional construction wastes a staggering amount of materials; some experts estimate that nearly a third of construction materials allocated at building sites end up in landfills. The Environmental Protection Agency in 2018 calculated that construction and demolition produced upwards of 600 million tons of waste debris annually, which is twice as much as the amount of municipal trash collected from homes and businesses.

The sad part is that this waste is the product of indifference on the part of builders; when one New York City builder decided to make an effort to cut down on construction waste, they were able to reduce it by 96% with only minimal effort.

During one single project, they were able to recycle over 5,600 tons of wood, electronics, sheetrock, and glass that would’ve otherwise gone to the dump. While this improvement is encouraging to recycling advocates, it also points out how wasteful business as usual has been.

On-site conventional construction can be very disruptive to the local community and environment. Sustained construction generates a lot of noise pollution, and microparticles of waste materials can linger in the environment for years or decades.

Air pollution is a particularly troublesome product of the conventional construction process; building and demolition often produce microparticles of substances like sulfates, silicates, concrete and cement, and even wood. Because these tiny particles are so small, they’re particularly dangerous to humans, since they can easily penetrate to the lungs, where they can cause inflammation and disease. 

Conventional on-site construction also uses potentially hazardous substances like high VOC paints, adhesives, oils, and plastics that can cause long-lasting environmental contamination.

Finally, much of this construction is performed by diesel-powered vehicles like bulldozers, cranes, and excavators, which produce proportionally large amounts of emissions. All in all, conventional construction is a dirty business. But it’s becoming increasingly clear that there’s a better, cleaner way.

The Sustainability of Prefabricated Homes

So why is prefab construction so much more sustainable than traditional construction? To put it simply, it comes down to containment, recyclability, and efficiency.

It starts with the way prefabricated homes are actually made. Prefab or modular homes are built off-site in a custom facility, while traditional construction requires workers and materials to be transported to many different sites each day. That transportation is a huge source of emissions. Because prefab homes don’t require any transportation other than the initial delivery of materials (which is dramatically more efficient, since they’re transported in bulk), experts say it generates only about half the amount of emissions that a conventionally constructed home generates.

Prefabrication also confines pollutants to a single facility, instead of disseminating them at every single individual construction site. Instead of flooding each building site with microparticles, diesel emissions, and miscellaneous chemicals, these byproducts are restricted to the fabrication site, where they can be efficiently remediated. 

The single site construction method also cuts down on waste. While traditional construction can send up to a third of allocated materials to the landfill, prefab construction is much better at utilizing all available materials. If there’s leftover steel or lumber after one project is built, they can easily be used on the next project. Off-cuts and surplus materials are integrated into subsequent projects instead of being sent to the landfill.

Prefab construction is also precisely planned and estimated, so there tends to be less material surplus; builders know exactly what they need from step one, and only order what’s required. And because prefab buildings are generally assembled indoors, in a specialized facility, the materials are protected from the weather; weather-damaged materials, caused by outdoor storage, is a huge factor in conventional construction wastage.

Prefab construction also cuts down on waste on the demolition side. When a conventional building reaches the end of its useful life, or if the owner wants to replace it with an updated structure, the existing building has to be torn down, and those materials are carted away to the dump.

Demolition is a huge factor in construction waste, and a big cause of emissions. But modular prefab homes are much more recyclable. Prefab structures can often be transported off-site, disassembled into their original components, and those components can be reused in subsequent structures. 

Because prefabricated homes are a new technology, they often incorporate the latest innovations in energy efficiency. This is especially true in European prefab homes, since they have to be built by much stricter regulatory standards than U.S. prefab homes.

Many prefab homes incorporate, by default, tech like solar panels, wind or geothermal power generation systems, and high-performance insulation; these homes can often function fully off-grid. And while they’re often constructed out of recycled materials, they’re just as often made of novel, high-efficiency materials like advanced composites and specialized wood products.

Many of these materials offer unprecedented durability along with energy efficiency that was considered impossible just a decade ago. For example, the latest in insulation technology can retain heat and cool air for much longer than previous generations of insulation could, lessening the demand on heating and cooling systems. 

Finally, prefab construction is much faster than conventional construction. While each conventional home has to be built from scratch, from the ground up, prefab homes can be rapidly assembled from their standardized components. In the U.S., where there’s a huge shortage of housing, and construction productivity has nosedived in recent decades, prefab construction represents a way out of this mess.

The irony is that the U.S. was once the industry leader in prefab housing. A government program called Operation Breakthrough from the 1970s pioneered a nationally standardized building code and prefabricated housing industry, quickly producing thousands of units in the early years of the seventies.

The pet project of HUD secretary George Romney (Mitt Romney’s father), Operation Breakthrough was intended to bring skyrocketing housing prices down by quickly increasing supply. (Sound like a familiar situation?) But Congress decided the project was too expensive and ambitious, and canceled it after only a handful of years. Still, foreign delegations studied Operation Breakthrough’s prefabricated housing, and took what they learned back home.

The Japanese experts were particularly intrigued by what they saw, and today 15% of Japanese homes are prefabricated. The Swiss were also convinced that prefabricated construction was the future, and today nearly half their construction is modular or prefabricated. The rest of the world studied American innovation, and improved on it. Now it’s our turn to relearn what we’ve forgotten.

About the Author

Tommy O’Shaughnessy is a St. Louis-based real estate writer and the owner of Rent a Backyard, a prefab home marketplace. His work has been featured in places like Yahoo Finance, Inman, and National Mortgage Professional.