Rule 12

• General Requirements


  Buildings proposed for construction shall comply with all the regulations and specifications herein set forth governing quality, characteristics and properties of materials, methods of design and construction, type of occupancy and classification
• National Structural Code of Buildings


  Provisions that all other matters relative to the structural design of all buildings and other structures not provided for in this Chapter shall conform with
• Excavation, Foundation, and Retaining Walls

  1. Structural materials and design must follow accepted engineering practices

  2. Consider legal provisions regarding lateral and subjacent support, as outlined in the Civil Code of the Philippines
• Excavation and Fills


  • Must be executed in a manner that doesn't jeopardize the well-being of individuals or property
  • If excavation work threatens the stability or safety of adjacent properties or structures, the responsible party must cover the expenses for reinforcing or extending the affected foundations or footings to ensure their stability
  • Any excavation or disturbances on public property must be restored to their original state within 48 hours from the start of the work unless the Building Official grants an exemption
• Footings, Foundations, and Retaining Walls

  • Footings and foundations must be designed to safely support the building's weight, even under challenging conditions like earthquakes
  • When abrupt changes in ground or foundation levels could cause soil instability at a construction site, retaining walls must be installed. These walls should be designed and constructed in accordance with the Secretary's requirements to ensure they are suitable for the specific site conditions
• Veneer


  A nonstructural layer of materials such as brick, concrete, tile, metal, plastic, glass, or other approved substances, affixed to the building's backing or structural components, serving the purposes of decoration, protection, or enclosure
• Design Requirements for Veneer


  • Veneer should not bear any load other than its own weight and the vertical dead load of the veneer directly above it
  • The surfaces to which veneer is attached must be designed to accommodate the additional vertical and lateral loads imposed by the veneer
  • Consideration should be given to potential differential movements of the supports, which may result from factors like temperature changes, shrinkage, creep, and deflection
  • Adhered veneer and its backing must be designed with a bond to the supporting elements strong enough to withstand shearing stresses, including those caused by their weight and seismic effects on the entire assembly
  • Anchored veneer and its attachment should be designed to resist horizontal forces equal to twice the weight of the veneer
  • Anchors, supports, and ties used in the veneer system must be non-combustible and corrosion resistant
• Enclosure of Vertical Openings

  • Vertical openings in buildings must be enclosed in accordance with the fire-resistance requirements specified in the building code
  • Elevator enclosures should have walls and partitions that meet the required fire-resistance standards based on the type of construction
  • Elevator shaft walls may have wire glass on the entrance side only
  • Elevator shafts extending through more than two stories must have adequate ventilation to the building's main roof
  • In buildings with automatic fire-extinguishing systems in Groups F and G Occupancies, escalator enclosures are not required, but a draft curtain must enclose the top of the escalator opening at each level, with automatic sprinklers installed around the perimeter of the opening
  • Other vertical openings, including shafts, ducts, and chutes, should have enclosing walls that comply with the building's construction type
• Floor Construction


  • Floors should be constructed with materials and techniques as specified in Chapter 5 (Fire Zones and Fire-Resistive Standards) and Chapter 6 (Types of Construction)
  • All floors should be securely framed and attached to the building's framework and supporting walls to ensure they are an integral part of the entire structure
  • The chosen floor construction must include measures to prevent lateral buckling of beams and girders, enhancing the structural integrity of the building
• Roof Construction and Covering

  1. Roof framing should be integrated into the building's framework and supporting walls

  2. Roof trusses should have well-fitted joints and tightened tension members before load application

  3. Diagonal and sway bracing should be used for stability

  4. Allowable working stresses of materials in trusses must adhere to the code

  5. Camber should be provided to prevent sagging

  6. Access to the attic is required in buildings with combustible ceiling or roof construction

  7. Enclosed attic spaces with combustible construction should be divided into smaller areas by fire-resistive partitions, except if the entire attic is equipped with an approved automatic fire-extinguishing system

  8. Draft stops are mandatory in truss roofs for larger buildings

  9. Adequate ventilation should be provided for enclosed attics and rafter spaces

  10. Roof drains should be installed at low points of the roof to handle all water runoff

  11. Adequate overflow drains should be provided when roof drains are required

  12. Concealed piping for roof drains and overflow drains should comply with the National Plumbing Code

  13. Roof drainage water should not flow over public property, except for Group A and J Occupancies

  14. Flashing and counterflashing must be installed at the junction of the roof and vertical surfaces to prevent water infiltration
• Stairs, Exits, and Occupant Loads


  • The occupant load for any building or part of a building is calculated by dividing the floor area designated for a specific use by a unit area allowed per occupant
  • The exit requirements for a building or its portions are determined by the occupant load that results in the largest number of people
  • Rooms with an occupant load of more than 50 people (where fixed seats are not installed) and are used for purposes like classrooms or assemblies should have the room's capacity (the maximum number of people it can safely hold) posted in a conspicuous location near the primary exit
  • Changes in floor elevations of less than 300 millimeters along any exit serving a tributary occupant load of 10 or more should be accomplished using ramps
  • Every building or usable portion must have at least one exit
  • Floors above the first storey with an occupant load of more than 10 must have at least two exits
  • Mezzanine floors used for purposes other than storage, if exceeding certain size criteria, must have at least two stairways to an adjacent floor
  • The total width of exits, measured in meters, must not be less than the total occupant load served divided by 165
  • If only two exits are required, they should be a distance apart equal to at least one-fifth of the perimeter of the area served, measured in a straight line between exits
  • Without a sprinkler system, no point in a building should be more than 45.00 meters from an exterior exit door, a horizontal exit, exit passageway, or an enclosed stairway, measured along the line of travel
  • Exit doors must swing in the direction of exit travel when serving hazardous areas or when serving an occupant load of 50 or more
  • Exit doors should be open-able from the inside without the use of a key or special knowledge or effort
  • Required exit doorways should be of a size allowing the installation of a door that is at least 900 millimetres wide and at least 2.00 metres in height
  • No leaf of an exit door should exceed 1.20 metres in width
  • Revolving, sliding, and overhead doors should not be used as required exits
  • There should be a floor or landing on each side of an exit door, leveled with or not more than 50 millimetres lower than the threshold of the doorway
• Exit doors


  At least 900 millimeters (approximately 0.9 meters) wide and at least 2.00 meters (approximately 2 meters) in height
• Exit doors

  Capable of opening at least 90 degrees, with a clear width of the exit way not less than 700 millimeters (approximately 0.7 meters)
• Door Leaf Width

  No leaf of an exit door should exceed 1.20 meters (approximately 1.2 meters) in width
• Special Doors


  Revolving, sliding, and overhead doors should not be used as required exits
• Egress from Door

  Every required exit door should provide immediate access to an approved means of egress from the building
• Change in Floor Level at Doors

  There should be a floor or landing on each side of an exit door, leveled with or not more than 50 millimeters lower than the threshold of the doorway
• Door Identification

  • Glass doors should conform to specific requirements in Section 1805
  • Other exit doors should be marked to be readily distinguishable from adjacent construction
• Corridor or Exterior Exit Balcony Width

  Every corridor or exterior exit balcony serving as a required exit for an occupant load of more than ten should have a minimum width of 1.10 meters (approximately 1.1 meters)
• Corridor or Exterior Exit Balcony Projections

  • The required width should remain unobstructed
  • Trim, handrails, and fully opened doors should not reduce the required width by more than 200 millimeters (approximately 0.2 meters)
• Access to Exits


  When more than one exit is required, they should be arranged to allow occupants to go in either direction from any point in the corridor or exterior exit balcony to a separate exit, except for permitted dead ends
• Dead Ends


  Corridors and exterior exit balconies with dead ends are permitted if the dead end does not exceed 6.00 meters in length
• Corridor and Exterior Exit Balcony Construction

  Walls and ceilings should have one-hour fire-resistant construction, with exceptions for certain occupancies and temporary partitions
• Corridor Wall Openings


  • Interior door openings should be protected according to requirements for dual-purpose fire exit doors
  • Other interior openings, except for ventilation louvers, should use 7-millimeter-thick fixed wire glass set in steel frames
  • The total area of all openings other than doors should not exceed 25% of the area of the corridor wall
• Stairway Width


  • Stairways serving an occupant load of more than 50 should have a minimum width of 1.10 meters
  • Stairways serving an occupant load of 50 or less may be 900 millimeters wide
  • Private stairways serving an occupant load of less than 10 may be 750 millimeters
  • Trim and handrails should not reduce the required width by more than 100 millimeters
• Stairway Rise and Run

  • The rise of each step should not exceed 200 millimeters, and the run should not be less than 250 millimeters
  • The maximum variation in the height of risers and the width of treads in any one flight should be 5 millimeters
• Winding Stairways

  Winding stairways may be used in Group A Occupancies and private stairways in Group B Occupancies if the required width of run is provided within specified limits
• Circular Stairways

  Circular stairs may be used as an exit, provided the minimum width of run is not less than 250 millimeters, and all treads in one flight between landings have identical dimensions
• Stairway Landings

  • Every landing should have a dimension equal to the width of the stairway
  • Landings should not be reduced in width by more than 100 millimeters by a fully open door
• Basement Stairways

  If a basement stairway and a stairway to an upper storey terminate in the same exit enclosure, an approved barrier should be provided to prevent access to the basement
• Distance Between Stairway Landings

  There should be no more than 3.60 meters of vertical distance between landings
• Stairway Handrails

  • Stairways should have handrails on each side, and wider stairways should have intermediate handrails
  • Handrails should be placed within specific height ranges and terminated correctly, with exceptions for narrower stairways and those serving individual dwelling units or having fewer than four risers
• Exterior Stairway Protection


  Exterior exit stairways serving buildings over two storeys should have protected openings, or openings may be unprotected when two separated exterior stairways serve an exterior exit balcony
• Stairway Construction

  Interior stairways and exterior stairways have construction requirements as specified in the code
• Stairway to Roof


  In buildings with four or more storeys, one stairway should extend to the roof unless the roof has a specified slope
• Stairway Headroom


  Every required stairway should have a headroom clearance of not less than 2.00 meters
• Ramps


  Ramps used as exits must adhere to the width requirements set for corridors
• Horizontal Exits


  • Horizontal exits, meeting code standards, can serve as required exits
  • Openings in the separation wall must have one-hour fire protection
  • The exit shouldn't lead to an area with a higher occupant load
  • Occupant capacity is calculated based on ambulatory and non-ambulatory occupants
  • The connected dispersal area must have exits as per code
• Exit Enclosure

  • Exit enclosures are required for interior stairways, ramps, or escalators, except in certain cases
  • The enclosure walls should have two-hour fire-resistive construction and should only have openings for exit doorways and openings in exterior walls, with all exit doors appropriately protected
• Smokeproof Enclosure


  • Stairs in smokeproof enclosures shall be of incombustible construction
  • The opening of the building to the vestibule or balcony shall be protected with a self-closing fire assembly having one-hour fire-resistive rating
  • There shall be no openings in smokeproof enclosures, except exit doorways and openings in exterior walls
  • A smokeproof enclosure shall exit into a public way or into an exit passageway leading to a public way
  • A stairway in a smokeproof enclosure shall not continue below the grade level exit unless an approved barrier is provided at a ground floor level to prevent persons from accidentally walking into the basement