Here is another sample problem, a project on a Basic R-2 zone. In this video, you can learn how to compute for the Allowable Maximum Building Footprint (AMBF), allowable maximum Percentage of Site Occupancy (PSO), allowable minimum Total Open Space within Lot (TOSL), allowable maximum Impervious Surface Area (ISA), allowable minimum Unpaved Surface Area (USA), Maximum Allowable Construction Area (MACA), allowable maximum Gross Floor Area (GFA) and allowable maximum Total Gross Floor Area (TGFA) based on the Revised Implementing Rules and Regulations (RIRR) of the National Building Code of the Philippines (NBCP).