A new Thai government planning regulation has been issued for Phuket. Legal firm Baker & McKenzie have issued a summary and analysis of the implications which we are reprinting with permission:
RECENT DEVELOPMENTS
On 7 July 2011, the Ministerial Regulation to Implement the Phuket Province Town Planning Regulation B.E. 2554 (the “2011 Regulation”) was [...]

For those of you considering buying land and building a house here in Thailand, you will need this importanat document which you can copy/paste
http://www.siamrealestate.com/docs/Environment-Quality-Promotion-and-Preservation-2546-Siam-Real-Estate.pdf
The above has now been supeceded see below Phuket Zoning Law