Gross Floor Area

Also known as: GFA · Total Floor Area · Gross Build Area

Definition

Gross Floor Area (GFA) is the total area of all floors of a building, measured from the outside faces of the exterior walls. In the Philippines, GFA is a standard metric defined under the National Building Code (PD 1096) and zoning ordinances to determine building density, compile construction cost estimates, and calculate development taxes. It excludes open-air areas, light wells, and parking structures under specific local rules. (Wikipedia, DHSUD)

Identities

Source Type	Identity
Wikipedia	Gross floor area
Wikidata	Q1547466
DBpedia	Gross_floor_area
ProductOntology	N/A
Wiktionary	area
Library of Congress Subject Headings (LCSH)	Architecture — Specifications — Philippines
MeSH	N/A
NCBI Taxonomy	N/A
AGROVOC	N/A
Google Scholar	Gross Floor Area GFA building density Philippines zoning National Building Code
ConceptNet	area
OpenCyc	N/A

Also Known As

GFA
Total Floor Area
Gross Build Area

Examples and Analogies

Density Calculation: A developer builds a 10-story condominium. Each floor plate measures 500 square meters of enclosed space. The Gross Floor Area of the building is 5,000 square meters.
Exempt Areas: An architect designs a building with a large open roof garden. The garden’s open-air terrace is excluded from the building’s GFA calculations under local zoning guidelines.

Usage Scenarios

1. Developer Project Costing

The development firm multiplies the calculated GFA of a project by the estimated construction cost per square meter (e.g., PHP 35,000/sqm) to establish the project’s base construction budget.

2. Zoning Compliance Audit

The municipal building official reviews the building’s blueprint to confirm that the proposed GFA does not exceed the maximum allowed under the lot’s Floor Area Ratio (FAR) limits.

Strategies

Ensure all non-enclosed spaces (like balconies, canopies, and open fire escapes) are correctly classified to prevent them from eating into the allowable GFA budget.
Optimize structural layouts to maximize the usable or sellable net area (semi-private space) within the gross floor area limit.

Security and Safety Measures

Do not attempt to hide illegal extensions or mezzanine floors from GFA reports, as this will lead to permit rejection or structural demolition mandates.
Verify local ordinances, as some highly urbanized cities include parking structures in GFA calculations if they exceed a certain percentage of the building size.

Historical Context

The definition of GFA was standardized in the Philippines with the implementing rules and regulations (IRR) of Presidential Decree No. 1096 in 1977. Local zoning revisions continue to refine what spaces are exempt from GFA.

Challenges and Controversies

Bonus Density Disputes

Developers frequently dispute with municipal assessors regarding which areas should qualify as “exempt” under local zoning codes to increase the buildable area.

Construction Violations

Some developers construct unapproved mezzanine floors post-inspection, leading to legal disputes and building closures.