NBCP Building Types

• Building Systems & Design - Week 11 - 2nd Semester 2025

Types of construction as per NBCP Section 401

• Buildings must be classified according to type in accordance with the Code and its Implementing Rules and Regulations (IRR).

Type I: Wood-Framed Construction

• Primarily wood construction utilizing any materials allowed by the Code for structural elements.

Type II: Heavy Timber Construction

• Wood composition that includes fire-resistant materials and one-hour fire resistance throughout.
• Fire-retardant treated wood may be used for permanent non-bearing partitions within the framing assembly that has one-hour resistivity.

Type III: Ordinary Construction

• Made of masonry and wood, with structural elements using code-permitted materials.
• Must have one-hour fire-resistance throughout and exterior walls of incombustible, fire-resistive construction.

Type IV: Non-Combustible Construction

• Features steel, iron, concrete, or masonry with incombustible fire-resistive walls, ceilings, and permanent partitions.
• One-hour fire-resistive construction may use fire-retardant treated wood for non-bearing partitions within the framing assembly.

Type V: Fire Resistive Construction

• Must have four-hour fire-resistive properties throughout.
• Structural elements consist of steel, iron, concrete, or masonry.

Concrete vs. Masonry

• Concrete is a composite of cement, sand, aggregate, and water that hardens into a durable substance.
• Masonry involves construction with brick, stone, or similar materials, bound by mortar.
• Poured concrete, reinforced or not, can be classified as masonry.

Iron vs. Steel

• Iron is a strong, hard, magnetic, silvery-gray chemical element used in construction and manufacturing, especially as steel.
• Steel is Iron and carbon alloy celebrated for its strength, durability for use in construction, manufacturing, and other applications.

Fire Resistive Requirements

• Exterior bearing and non-bearing walls must have a one-hour fire-resistive rating for Types II and III, and four hours for Types IV and V.
• Interior bearing walls, permanent partitions, floors, and roofs must have one-hour fire-resistive rating for Types II, III, and IV, with three hours for bearing walls for Type V.
• Structural frames have a one-hour fire-resistive rating for Types II and III, two hours for Type IV, and three hours for Type V.
• Exterior doors and windows must have a one-hour fire-resistive rating for all types.

Interior Wall and Ceiling Finishes

• Finishes must be classified by flame-spread characteristic of generally accepted engineering standards.
• Smoke density should not exceed that of burning untreated wood under similar conditions.
• Combustion products should be no more toxic than burning untreated wood.
• These finishes include interior wainscoting, paneling, decoration, acoustical correction, frames and trims of doors/windows, and surface insulation.
• Requirements do not apply to frames, trims of doors/windows, and materials less than 1.00 mm thick.
• Materials that require flame-spread proofing must be treated with a flame-retardant with a flame-spread of 50 or less per the "Tunnel Test".

Material Standards

• Use in structural frameworks, exterior walls, openings, floors, exits, stairs, and roofs must comply with the Fire Code of the Philippines provisions.

Tunnel Test (ASTM E84)

• Used to assess the surface burning behavior of building materials by measuring flame spread and smoke density.