Warranty of habitability. During the rental of any premises for residential purposes, whether pursuant to a written or oral lease and whether for a specified term or as a tenant at will, there exists an implied warranty of habitability requiring “that the premises are fit for human occupation.” Boston Hous. Authy. v. Hemingway, 363 Mass. 184, 199 (1973). “This means that at the inception of the rental there are no latent [or patent] defects in facilities vital to the use of the premises for residential purposes and that these essential facilities will remain during the entire term in a condition which makes the property livable.” Ibid.., quoting from Kline v. Burns, 111 N.H. 87, 92 (1971). Our modem view has determined that a residential lease is a contract between a landlord and a tenant. The landlord promises to provide and maintain residential premises in a habitable condition. The tenant promises to pay the agreed upon rent for the habitable premises. “These promises constitute interdependent and mutual considerations. Thus, the tenant’s obligation to pay rent is predicated on the landlord’s obligation to deliver and maintain the premises in habitable condition.” Id. at 198. We have required a material and substantial breach of the warranty, representing a significant defect in the property itself, in order to excuse the tenant’s obligation to pay rent. For example, “[a] dwelling afflicted with a substantial Sanitary Code violation is not habitable.” Berman & Sons, Inc. v. Jefferson, 379 Mass. 196, 201-202 (1979).