d. The owner and tenant of any dwelling unit in a multiple dwelling may, by voluntary agreement, provide that the owner need not repaint in such unit as required by paragraph two of subdivision b of this section for such additional period, not to exceed two years, as may be agreed upon. Such an agreement to extend the time for repainting shall not be valid unless it has been entered into not earlier than one month prior to the expiration of the three-year period, and shall not form part of any agreement of lease. The department may prescribe the form of such agreements, require them to be filed, and may make such other regulations as may be necessary to avoid abuse, and to further the purposes of this article. Notwithstanding any agreement, the department may, during the period for which repainting is deferred by agreement order repainting by the owner in any dwelling unit when deemed necessary to keep the walls and ceilings of such unit sanitary. This subdivision shall not affect the applicability of subdivision c of this section during the three years after any repainting or re-covering.
e. Neither the owner nor a tenant of a dwelling unit shall place wallpaper or wall covering upon a wall or ceiling in the public or tenant-occupied parts of a dwelling unless existing wallpaper or wall covering is first removed and such wall or ceiling is cleaned and repaired. However, if wallpaper or wall covering is in good condition, free from vermin and a coat of acceptable paint or sizing is applied, one additional layer of wallpaper or wall covering may be applied.