What is the decrease in value of an apartment infested with mice, cockroaches and badly in need of repairs?

Sheridan 1511 LLC v. Fofana, NYLJ October 02, 2019, ate filed: 2019-09-11, Court: Civil Court,  Judge: Judge Diane Lutwak, Case Number: 32176/2018:

“Accordingly, for the 19-month period from February 2018 through August 2019 Respondent is entitled to a 25 percent  abatement of the rent due to the unresolved infestation of mice. For the 13-month period from February 2018 through February 2019 Respondent is entitled to an additional 5 percent  abatement due to the cockroach infestation which Respondent testified he had resolved as of March 1, 2019.

Further, the court finds that other conditions existed at least as of the August 17, 2018 stipulation and continued through some point in January or February 2019 which warrant an additional 10 percent  abatement, see, e.g., Tower West Associates v. Derevnuk (114 Misc2d 158, 450 NYS2d 947 [Civ Ct NY Co 1982]), for this approximately 5-month period: defective flooring in the hallway, kitchen and bathroom; peeling paint throughout the apartment; defective light fixtures throughout the apartment. Petitioner offered no evidence or testimony about any attempts to make repairs during this time period; rather, it was Respondent who testified that Petitioner had substantially corrected these conditions by March 2019, with only the defective bedroom light fixtures remaining unresolved.
Respondent’s testimony was not clear and the record otherwise is insufficient to show dates after January 23, 2018 when the conditions existed involving the bathroom flushometer, kitchen cabinets, elevator, building entrance door, water leaks into the public lobby and public stairway; accordingly, the Court declines to award a further abatement for these items. See, e.g., Mantica R Corp NV v. Malone (106 Misc2d 953, 436 NYS2d 797 [Civ Ct NY Co 1981]). Although HPD wrote up violations of some of these items on April 27, 2018 and sent notice to the landlord on May 3, 2018, HPD’s records show that by June 8, 2018 it had received the landlord’s certification that the violations had been corrected.”