Principles of Planning
The regulatory frame
Almost every planning question is answered by PD 1096 (National Building Code) and its 2005 IRR, the local zoning ordinance derived from the CLUP, BP 344 (Accessibility Law) and RA 9514 (Fire Code). Learn the vocabulary precisely: allowable maximum building footprint, percentage of site occupancy (PSO), impervious surface area (ISA), floor area ratio (FAR), building height limit (BHL), and the required yards/setbacks for front, side and rear. Setbacks in the NBCP depend on the road right-of-way width and the use classification; the zoning ordinance may impose stricter values, and the stricter one governs.
Light, ventilation, egress, parking
Habitable rooms need natural light and ventilation: the NBCP requires window openings of roughly 10% of the room's floor area, at least half of which is openable. Ceiling heights, minimum room dimensions, corridor widths, exit counts, travel distance, exit width and dead-end limits are all prescriptive numbers - memorize the common ones and read carefully whether the question asks for minimum or provided. Parking ratios come from the local ordinance, not the NBCP.
Traps and a rule of thumb
Traps: confusing PSO with FAR; applying setbacks as measured from the property line when the question says building line; forgetting that BP 344 ramp maximum slope is 1:12 with landings; and assuming one window formula covers kitchens and bathrooms. Rule of thumb for space planning: allow about 25–35% grossing factor over net usable area for circulation, partitions and mechanical. If a program needs 700 m² net, plan on roughly 900–950 m² gross before checking it against the PSO and FAR.