in preparing defective plans. This third-party claim is now before the Court for adjudication.
It is not denied that Frishman retained Previll to prepare the plans for the air conditioning system, and that Previll did so. Those plans were modified and Previll approved the modifications. An air conditioning system was then installed. It departed from both the original and revised plans. There is a dispute, for example, whether it was necessary to subdivide the air conditioning apparatus on each floor into three zones, or whether a single zone was sufficient. The dispute appears to be more or less academic, because the plaintiff's expert witness, Herbert Arey, admitted that the shop drawings which the plaintiff has introduced in evidence, and which were later revised, did show three zones. Even a layman, by examining those plans, can observe the designations: zone 1, zone 2, zone 3. The system actually installed contained pumps that were located in the penthouse, whereas the specifications and the drawings called for them to be on the first floor.
The evidence showed that the system actually installed did not operate properly and that certain changes were necessary, which Mr. Frishman ordered. There is not sufficient showing, however, that the original plans, which were not followed, or the revised plans, which also were not followed in detail, would not have been satisfactory. There is no evidence that the defects were not due to the departure from the plans. There is no showing that the third-party defendant was guilty of any negligence or lack of due care, or failure to comply with the prevailing standards in his profession.
This brings us to the question what rule should be applied to the liability of an architect or an engineer to his principal. A professional man is not a guarantor of his work. For example, a physician is not liable for damages if he fails to cure his patient. A lawyer is not liable for damages if he fails to win his case. A professional man is under an obligation to use due care and also to comply with the standards prevailing in his area and followed by other members of the same profession in the same specialty. In other words, he is liable only for negligence.
This principle has been frequently applied to physicians and surgeons. A succinct statement of this doctrine is found in an opinion of the Court of Appeals in Rodgers v. Lawson, 83 U.S.App.D.C. 281, at 282, 170 F.2d 157, 158, where Stephens, J. wrote:
"The principles of law governing malpractice actions are well settled. A physician 'must exercise that degree of care and skill ordinarily exercised by the profession in his own or similar localities.' * * * The burden of proof is upon a plaintiff to establish by substantial evidence departure from that standard and that such departure caused the injury complained of."