The site, on the corner of Northgate Avenue and Woodfield Road, includes Centenary House, the old police station and the old library, as well as offices currently leased to a dental practice.
The magistrates court building is not included in the project.
Jeremy Hunt, cabinet member for finance and resources, has approved the use of £857,000 for the demolition and, if it is not called in for further debate by other councillors, it will come into force on August 1.
A report published today (July 24) said the site could be used for up to 195 homes as well as several thousand square metres of commercial space, which could be used for shops and offices.
The council would have to submit a planning application to demolish the site.
It will also have to move the few remaining occupants, with the aim of emptying the site by April 2020.
The report said that the Coroner’s Court could be moved to the former Bartons Infant School site, in Bersted, at a cost of around £150,000.
The council is exploring moving the Find It Out and YES youth services to Crawley Library, while the dental practice’s lease runs out in October and will not be renewed.
Council officers are working with the practice and with the Change, Grow, Live service for ex-offenders, which is based at Centenary House, to find them suitable new homes.