The county council plans to build 200 council homes and 300 affordable homes.
The first will be built on the site of the former Custom House Lane School in Connah's Quay.
Meanwhile, the nearby "old dairy" on Mold Road is being flattened along with some terraced homes on the adjacent High Street. The former dairy has stood empty for more than 30 years.
The council has asked experts to draw up proposals for the site, which will be levelled and seeded once demolition work is completed in March.
Building work is due to start next month on the first new council homes in Flintshire for more than 20 years.