Brown Field Municipal Airport Land Use Compatibility Plan

APPENDIX DMETHODS FOR DETERMINING CONCENTRATIONS OF PEOPLEmaximum number of building floors, minimum setback distances from the property line, and minimumnumber of parking spaces. These requirements effectively limit floor area ratio as well.To facilitate local jurisdictional implementation, Table III-2 in Chapter 3 has structured around FARmeasures to determine usage intensity limits for many types of nonresidential land use development. Touse FAR in this manner, a critical additional piece of information is necessary to mitigate a shortcomingof using FAR as a safety compatibility measure. FAR does not directly correlate with risks to peoplebecause different types of buildings with the same FAR can have vastly different numbers of peopleinside—a low-intensity warehouse versus a high-intensity restaurant, for example. For FAR to be appliedas a factor in setting development limitations, assumptions must be made as to the amount of space eachperson (employees and others) in the building would occupy. Table III-2 indicates the assumedoccupancy load factor for various land uses. Mathematically, the relationship between usage intensityand FAR is:Floor Area Ratio =(allowable usage intensity) x (occupancy load factor)43,560where usage intensity is measured in terms of people per acreand occupancy load factor is measured as square footage per person.The land use types in Table III-2 are organized, in part, based upon CBC occupancy type classifications.These classifications are indicated in the table. Table D-5 below briefly describes each of theseclassifications. Other land use types, especially ones not associated with buildings, were added to thetable to better address the range of land use categories included in general plans and zoning ordinances.For most of these added land use types, FAR limits are not applicable.The usage intensity, occupancy level, and FAR numbers in Table III-2 were selected in an iterativemanner wherein each component was considered both separately and together. Usage intensities wereinitially set with respect to guidelines provided in the Handbook (see Appendix C). Occupancy levelswere derived from the CBC, but were adjusted based on additional research of both local and nationalsources as discussed earlier in this appendix. The FAR limits were initially calculated from these othertwo measures using the formula above.Additionally, research was conducted to determine the typical FARs of existing development in thevicinity of urban airports in San Diego County. Extensive data provided by the City of Carlsbad indicatethat most of the development near McClellan-Palomar Airport has a FAR of 0.40 or less (some smallparcels that are part of larger sites and do not individually include parking have higher FARs). The Cityof Carlsbad does not have a defined maximum FAR, but buildings have a three-story height limit.Parking typically is all at ground level. FARs in the City of San Diego are higher, particularly for morerecent development. City of San Diego staff indicates that the typical FAR for new office and industrialuses in its jurisdiction is 2.0. Table D-6 summarizes the usage intensities that correspond to the aboveFAR data.D–7Brown Field Municipal Airport Land Use Compatibility PlanJanuary 25, 2010