D alleged that P breached a substantial obligation of her tenancy in the following four ways: (1) installing a new wood deck and concrete patio without permission or knowledge of P; (2) allowing debris to be accumulated in the backyard; (3) covering boiler vents with garbage bags; and (4) placing graffiti defacing the exterior walls of the backyard. D testified that in 1988 she had painted poetry on the walls of her courtyard. The poetry does not affect P's reversionary interest. There is no evidence that P or its predecessor in interest, by whom petitioner is bound, objected to the writings prior to 1999. D's claim for possession based upon this alleged violation of the lease is time-barred. D did not carry its burden of proving that P created a hazard to others living in the building or to the building itself. The court dismissed those counts in the complaint. P proved its assertion that it gave no permission to make any alterations to the subject apartment or the adjacent yard constituting part of the leasehold. P did this by before and after photographs. They showed that the appearance of the prior wooden deck was old and somewhat shabby, with at least one of the boards warped, creating a slightly uneven floor surface, and small, but not atypical or dangerous, gaps between the boards. D made no claim and presented no evidence that the condition of the prior deck violated any applicable housing laws. D proved that she feared that the condition of the deck could cause injury to the child as a result of the width of the crevices between the wooden boards. D attempted to contact the landlord at the beginning of June 1999, prior to installing the new deck and patio but received no return call. D replaced and covered the area with clean, new wood. D estimated that the new deck was six inches to one foot longer. P's agent testified that the deck was a couple of feet longer at each end. The new structure had steps attached and was significantly bigger. The new deck had an attractive, even appearance was not disproportionate to the space, and looked as if it had been completed in a worker-like manner, although D offered no testimony as to the manner of construction or the quality of the materials used. This patio was at ground level several feet to the rear of the wooden deck. The court found that D installed a new structure where only debris had previously been located. The patio had a well-finished appearance, and the work appeared to have been neatly done. D conducted this work without P's permission.