Design defect claims represent some of the most significant product liability cases because they affect every unit of a product built to the flawed specifications. Unlike manufacturing defects that impact only certain items, design defects make entire product lines dangerous. When fundamental design choices create unreasonable risks of injury, manufacturers may be held liable for all resulting harm.
Understanding Design Defects
A product has a design defect when its intended design makes it unreasonably dangerous for its foreseeable uses. The manufacturer built exactly what it intended to build—the problem is that what it intended to build poses unacceptable risks. This distinguishes design defects from manufacturing defects, where individual products deviate from otherwise acceptable designs.
Design defects may exist even in products that work exactly as intended. A space heater that functions perfectly but tips over easily, igniting nearby materials, has a design defect. An automobile that provides comfortable transportation but explodes on rear impact has a design defect. The product achieves its primary purpose but creates dangers that a reasonable alternative design could have avoided.
How Courts Evaluate Design Defects
Jurisdictions use different tests to determine whether a design is defective. Under the consumer expectations test, a design is defective if the product fails to perform as safely as an ordinary consumer would expect when using it in a reasonably foreseeable manner. This test works well for simple products with obvious safety expectations but may be difficult to apply to complex products where consumers have no clear expectations about internal design choices.
The risk-utility test provides a more sophisticated analysis, weighing the product's utility against the magnitude and probability of the risk it creates. Courts consider factors including the severity of potential harm, the likelihood of that harm occurring, the feasibility of alternative designs that would reduce risk, the costs of implementing safer designs, and the effect on product utility. A design is defective if a reasonable alternative design would have reduced the risk of harm and the failure to adopt that design made the product unreasonably dangerous.
Proving Alternative Design Feasibility
Design defect plaintiffs typically must demonstrate that a reasonable alternative design existed that would have reduced the risk of injury. This does not require proving that a perfectly safe design was possible—only that a safer design was feasible and would have prevented or reduced the plaintiff's harm without unreasonably compromising the product's utility or making it prohibitively expensive.
Expert witnesses play crucial roles in design defect cases. Engineering experts analyze the challenged design, identify its shortcomings, and present alternative designs that would have avoided the danger. They may demonstrate that safer designs were already in use by competitors, were technologically feasible at the time of manufacture, or have since been adopted by the industry in response to the defect's dangers.
Common Design Defect Scenarios
Design defects appear across virtually every product category. Automotive design defects have involved roof crush in rollovers, side impact vulnerability, and fuel system fires. Children's products have featured choking hazards, tip-over risks, and entrapment dangers. Medical devices have used materials that degraded in the body or configurations prone to failure. Consumer electronics have presented fire and shock hazards.
What unifies these diverse cases is that the danger stemmed not from production errors but from fundamental design choices that prioritized cost, aesthetics, or convenience over safety when safer alternatives existed.
Design Defect Case Value
Because design defects typically affect many consumers, these cases often become class actions or mass torts consolidating numerous individual claims. Individual cases involving catastrophic injuries—paralysis, severe burns, wrongful death—command substantial compensation reflecting the magnitude of harm that negligent design choices caused. Consulting with experienced product liability counsel helps injured consumers evaluate whether design defect theories apply to their situations.