The move, by Inverclyde Council, paves the way for the regeneration of the Clune Park area of Port Glasgow.
And once a sufficient number of orders are in place the council will press ahead to secure demolition orders over entire blocks of flats.
Council leader Stephen McCabe, who is also chairman of the Clune Park Task Group, said: "Through discussions with landlords four projects have been included in the Strategic Housing Investment Plan to meet the housing needs of existing residents.
"We have said from the very beginning that the only effective solution for Clune Park is to re-house local residents and demolish over 400 homes.
"We have committed over £2 million to the process."
The needs of households and individuals are being assessed through the completion of personal housing plans, which set out their wishes for alternative housing and their personal and financial circumstances.
A physical survey of all 430 flats has been carried out to identify flats and entire blocks that can be closed using existing housing legislation.
A total of 48 Closing Orders have now been served with a further 16 in progress.
Communities convener, councillor Terry Loughran, added: "The regeneration is a top priority for the council and I am encouraged by the work that has been done to date.
"We are committed to changing the fortunes of the people who live there and to begin to provide quality, affordable homes that they can be proud of.
"We have submitted our revised regeneration plan to the Scottish Government and I would hope they will match our ambitions for the area."