A party participating in the completion of a project is generally only responsible for the portion of the project over which it has control. For example, a contractor who manufactures a product following the plans and specifications of the purchaser will not be held liable for an injury caused by an alleged design defect in the product.  The exception would be a situation in which in performing the work he was hired to perform, a contractor follows plans which are “so apparently defective, that an ordinary builder of ordinary prudence would be put on notice that the work was dangerous and likely to cause injury.”  The contractor may then be held liable to an injured third party if the defects were so obvious that the plans put him on notice that the work he was performing by following said plans would cause injury.
In some instances, several parties may even be held liable for the same defect. This was the cause in Doundoulakis v. Town of Hempstead, 42 N.Y.2d 440, 398 N.Y.S.2d 401 (1977). Plaintiffs were three separate owners of private homes built on filled sandy soil on Long Island, sought to recover for property damage. The damage, subsidence of their lands, was allegedly caused by a hydraulic landfilling project conducted by defendants, the Town of Hempstead, its contractor, and its design engineer. The court found that if the landowner engages in an abnormally dangerous activity, as the Town of Hempstead did there, any architects or engineers that help design the project as well as any contractors who implement said project may be held jointly liable with the owner for damages caused as a result of the project.
Similarly, Spano v. Perini Corp., 25 N.Y. 11, 302 N.Y.S.2d 527 (1969) was an action to recover damages allegedly resulting from blasting operations. Plaintiff’s, who owned property adjacent to a blasting zone, brought suit against the two defendants who, as joint venturers, were engaged in constructing a tunnel in the vicinity pursuant to a contract with the City of New York, after their property was damaged during the course of the project. In addition to finding that one who engages in blasting must assume responsibility, and be liable without fault, for any injury he causes to neighboring property, the court once again held that not only landowners but also various workers involved in the project such as blasting contractors could be held liable for damage to another’s property.
Aside from an outright waiver of defects, the parties to the contract may apportion the liability of any defects amongst those involved. For example, a standard contract drawn up by the American Institute of Architects’ has a clause that limits contractor liability. Should the parties choose, they can elect to contract to this limitation and establish that the contractor on the project will not be responsible for design defects unless it recognizes the error in the plans, fails to report said error to the architect on the project, and performs the work despite said defect.