In the early 1980s, while most Upper West Siders were breathing a sigh of relief that the neighborhood’s seedy, sometimes menacing single-room-occupancy hotels were being converted into co-ops, a few residents of West 87th Street worried about the fate of the hotels’ tenants, particularly those in the S.R.O. on their block, the Capitol Hall.

Thirty-three years ago, in a bold, practically unheard-of stroke, they actually bought the 10-story hotel, enlisting Goddard Riverside Community Center and other nonprofit organizations as well as government agencies to help finance the purchase. The price: $1.95 million, what a two-bedroom co-op might sell for today. They saw to it that social workers were installed and security was in place at the hotel entrance, and they took turns getting to know the tenants and running activities like Bingo. While there have been occasional disturbances to ruffle the leafy, largely brownstone block’s calm demeanor, the hotel has provided permanent homes for hundreds of the poor, frail, elderly, troubled or addicted.

Last month, the hotel’s neighbors and its many donors celebrated the completion of a $16.7 million, top-to-bottom renovation of the building that has finally provided the 200 current tenants their own bathrooms and kitchenettes, and created community rooms to flavor their days with Netflix movies, gab sessions, gardening and more. The renovation, capitalizing on newly available government preservation funds, has reduced the residents’ indignities.