It has already proved controversial as language campaigners claim new housing developments could worsen the decline of Welsh speakers in the area.
The plan will focus on Carmarthen West, Cross Hands, Ammanford and Llanelli.
The Local Development Plan sets out the strategy and policies that will shape the county between 2006 and 2021.
A plan for 15,000 new homes in Carmarthenshire has been approved by councillors.