Chapter 18.20 PRESERVATION DISTRICT – P DISTRICT This chapter is included in your selections. Sections: 18.20.010 Intent. 18.20.020 Permitted and principal uses and structures. 18.20.030 Conditional uses. 18.20.040 Minimum lot size and dimensions. 18.20.050 Minimum setback requirements. 18.20.060 Maximum height of structures. 18.20.070 Minimum requirements for marijuana cultivation facilities.