Talks over the takeover of a closed Sudbury school are on-going.
The Befriending Scheme, The Bridge Project and The Stour Valley Vineyard Church are all interested in occupying parts of Uplands Middle School in York Road.
The three charities were told in September that proposals to use the building should be concluded by November, but Suffolk County Council, which owns the site, has allowed more time for workable plans to be drawn up.
A spokeswoman for the council said: “Nothing has been decided yet and discussions are still taking place.”
It is hoped that once plans are finalised, the charities will be offered a short-term lease of the building until August next year.
But it is still unclear how the building, which costs around £100,000 a year to maintain, would be divided and how other community groups would access the site.
Anesta Newson, chief executive of the Bridge Project in Gainsborough Street, said the charities faced a difficult task in making the project viable.
“The building is a lot bigger than we expected and it is a huge project,” she said.
The Befriending Scheme is keen to set up a training academy on the site.