Defendants' expert's affidavit established that the subject door saddle was free of defect in design, installation or maintenance and had none of the characteristics of a snare or trap; that the hazard, if any, posed by the ¾-inch height differential between the edge of the saddle and the kitchen floor was trivial; and that the New York City Building Code violations alleged by plaintiff were without merit. Plaintiff's expert's affidavit failed to raise a triable issue of fact as to defendant's negligence inasmuch as it was couched in general terms, referred to New York City Building Code sections that did not specifically address door saddles, and offered unsubstantiated conclusions regarding the alleged dangerous tripping hazard posed by the door saddle and regarding what constitutes good and accepted engineering practice in these circumstances ( see Bean v. Ruppert Towers Hous. Co., 274 AD2d 305, 308).