The District Court also failed to make any findings with respect to tenant's counterclaims, including landlord's alleged breach of the warranty of habitability. "[A] deprivation of light, air and ventilation constitutes a breach of the warranty of habitability" (Edgemont, 170 Misc 2d at 1042; see Sutton Fifty-Six Co. v Garrison, 93 AD2d 720 [1983]). Tenant alleged that five of the seven windows in the premises could not be opened. We note that, despite the District Court's statements to the effect that expert testimony was required to evaluate the repairs that were allegedly necessary, Real Property Law § 235-b provides, in pertinent part, "In determining the amount of damages sustained by a tenant as a result of a breach of the warranty [of habitability], the court . . . need not require expert testimony."