The promise of factory efficiency in prefab housing is often erased by new costs. Modules must be over-engineered to survive road transport—a primary design constraint—and then require complex, costly on-site work to connect, negating initial savings.

The collapse of Katerra, which burned through $2-3 billion in VC funding, shows that simply applying factory models to construction is not enough. The startup's failure highlights that deep, systemic issues like logistics, regulation, and on-site complexity cannot be solved by capital alone.

The core bottleneck in construction isn't design intelligence but the high cost and stagnant productivity of manual labor. The most promising application of AI is not designing more clever prefabricated buildings, but powering robots to automate physical tasks, finally addressing the industry's decades-long productivity problem.

Unlike lightweight goods, heavy housing modules are uneconomical to ship more than a day's drive. This physical constraint prevents the creation of massive, centralized factories, forcing a model of smaller, distributed plants that cannot achieve the same economies of scale.

The well-funded startup Katerra invested heavily in expensive factories for specific products, like cross-laminated timber, before confirming market demand. This is a fatal flaw for a physical goods company, as pivoting away from $100M factories is prohibitively expensive, leading to their eventual bankruptcy.

The housing industry is resistant to startup disruption due to immense "activation energy." This includes hyper-local regulations, fragmented distribution, cyclical capital needs, and a complex web of legacy players. Overcoming this barrier requires decades of effort, creating a powerful moat for incumbents.

Contrary to most industries that see technological gains, housing construction has become less efficient. This stagnation is a key, often overlooked driver of housing affordability issues, as the fundamental cost to build has not decreased with technology.

Despite up to 90% of its single-family homes being factory-built, Sweden's housing costs are higher than in the U.S. This real-world case study proves that even at scale, prefabrication does not automatically solve the fundamental cost drivers in construction, serving as a cautionary tale for innovators.

The American Housing Corporation uses a factory-based manufacturing process to create home panels that can be shipped and assembled anywhere. Co-founder Bobby Fijan explains this model allows them to offer a fixed price for the core structure, detaching the cost from wildly variable local construction labor markets in places like San Francisco or Houston.