NBCP Rule XII: General Design and Construction Requirements Summary

General Design & Construction Requirements

Buildings must comply with safety standards for materials, design, construction, occupancy.
Referral codes supplement planning, design, construction, location, and maintenance.
Secretary issues lists of approved/regulated/banned items for design, construction, and occupancy.
Buildings must be on private property or designated public land and securely constructed.

Excavation, Foundation, & Retaining Walls

Design/materials for excavation, footings, foundations must conform to engineering practices.
Excavation/fills shouldn't endanger life/property.
Excavator is responsible for underpinning adjoining property if excavation endangers it.
Disturbances on public property must be restored within 48 hours.
Contact public utilities before excavation to locate underground facilities.
Protect adjoining property during excavation below existing grade.
Notify property owners 10 days before excavation.
Survey cracks in adjacent buildings before starting work; record and photograph.
Permanent excavation slopes: not steeper than 2 horizontal to 1 vertical.
Deep excavation safety: geotechnical/geological site investigation needed.
Water-bearing stratum: form a bench with an intercepting drain.
Reduce groundwater head around excavation using weepholes or sheet piling.
Line excavations (except in certain cases) with shotcrete, boards, or sheet piles.
Linings/framings should be inserted as excavation proceeds and tightened.
Trenches deeper than 1.50 meters require exits every 7.50 meters.
Provide railings/fences to prevent workers falling into excavations.
Periodic inspection of timbering/strutting is required for open excavations.
Arrange long excavations in alternate sections for safe support.
Maintain a sump to pump out water encountered in excavation.
No surcharge loads near buildings unless they can withstand the loads.
Existing footings affected by excavation must be underpinned/protected.
Fills supporting foundations require a soil investigation report.
Footings and foundations: adequate size/capacity for superimposed loads.
Retaining walls needed where abrupt changes in ground levels occur.

Veneer

Veneer supports only its own weight and the vertical dead load above.
Surfaces for veneer must support additional vertical/lateral loads.
Account for differential movements due to temperature, shrinkage, creep, deflection.
Adhered veneer should withstand shearing stresses, including seismic effects.
Anchored veneer: resist horizontal forces equal to twice the veneer's weight.
Anchors, supports, ties: non-combustible and corrosion-resistant.

Enclosure of Vertical Openings

Vertical openings must be enclosed based on fire-resistive requirements.
Elevator enclosures: fire-resistive construction.
Elevator shafts extending through >2 stories: ventilation to main roof.
Shafts, ducts, chutes: enclosing walls per building type's construction requirements.
Rubbish/linen chutes terminate in rooms separated by a 1-hour fire-resistive separation.
Air ducts passing through floors: enclosed in a shaft.
Dampers installed where ducts pierce shaft enclosure walls.

Floor Construction

Floors must meet fire zone/fire-resistive standards and construction type.
Floors framed and secured into framework/walls to form an integral part of the building.
Floor construction should prevent lateral buckling of beams/girders.

Roof Construction & Covering

Roof covering: fire-retardant or ordinary, based on fire-resistive needs.
Combustible roof insulation permitted if covered with approved roofing.
Roofs must be framed/tied into framework/walls.
Roof trusses: joints well-fitted, tension members tightened, diagonal/sway bracing used.
Materials in trusses: conform to code's allowable working stresses.
Camber provided to prevent sagging.
Attic access: required in top floor ceilings of combustible construction.
Attic access opening size minimum: 600mm square/diameter; 800mm headroom.
Enclosed attic spaces: divided into < 250 m^2 areas by fire-resistive partitions, unless sprinklered (then, < 750 m^2).
Draft stops: installed in trussed roofs > $2000 m^2$ .
Enclosed attics: adequate ventilation protected against rain.
Roof drains: installed at low points, adequate size for tributary waters.
Overflow drains: required where roof drains are necessary.
Concealed piping: per National Plumbing Code.
Roof drainage water: not flow over public property (except Group A/J occupancies).
Flashing: provided at roof/vertical surface junctions.

Stairs, Exits, & Occupant Loads

Stairs/exits: conform to occupant load requirements.
Occupant load: floor area / unit area per occupant (Table XII.1).
If unit area not in Table XII.1, Building Official determines based on similar occupancy.
Fixed seating areas: occupant load = number of seats; aisles included.
Occupant load may increase if necessary exits provided.
All building portions presumed occupied simultaneously.
Exit requirements based on largest occupant load.
No obstructions in required exit width.
Rooms with > 50 occupant load (no fixed seats): capacity posted near main exit.
Elevation changes < 300mm along exits (≥ 10 tributary occupant load): use ramps (except Group A Occupancies).
Every building must have at least one exit.
Floors above the first story with occupant load > 10: minimum 2 exits.
Floors w/ occupant load 500-999: 3 exits; 1000+: 4 exits.
Exit number calculation: 50% of adjacent storey's load, 25% of the next storey.
Basements/cellars and occupied roofs: exits as required for storeys.
Floors above the second story, basements and cellars (not used for building service) need at least two exits.
Total exit width: occupant load / 165 (meters); divided approximately equally among exits.
Exit arrangement: for 2 exits, minimum 1/5 perimeter apart; for 3+, reasonable distance apart.
Distance to exits: 45m max (no sprinklers), 60m (with sprinklers).
Exit doors should swing in the direction of travel (serving hazardous areas or loads > 50).
Exit doors: openable from inside without keys; conspicuous signs required for Group E/F exceptions.
Required exit doorways: minimum width 900mm, height 2.00m; clear width ≥ 700mm.
No leaf of an exit door shall exceed 1.20 meters in width.
Revolving, sliding, and overhead doors shall not be used as required exits.
Floor/landing on each side of exit door, leveled or max 50mm lower than threshold (exceptions for Group A/B).
Glass doors: conform to Section 1802; other exit doors: distinguishable from surroundings.
Corridors/exit balconies: minimum 1.10m wide, unobstructed (except trim, handrails, doors).
Dead ends permitted in corridors/exit balconies when ≤ 6.00m long.
Corridor walls/ceilings: minimum one-hour fire-resistive construction (exceptions noted).
Where corridor walls need to be one-hour fire-resistive, the interior door opening shall be protected as set forth in generally recognized and accepted requirements for dual-purpose fire exit doors. Other interior openings except ventilation louvers equipped with approved automatic fire shutters shall be 7 millimeters thick fixed wire glass set in steel frames.
Stairways (serving > 50 occupants): min 1.10m wide; (≤ 50): 900mm; private stairways (<10) may be 750 mm.
Stair rise: max 200mm; run: min 250mm (variations allowed); handrails required.
Exterior stairway protection: openings within 3.00m require 3/4-hour fire assembly.
Ramps: width as required for corridors.
Horizontal exits: separations require one-hour fire-resistive rating.
Horizontal exits: not lead into an area having a capacity for an occupant load not less than the occupant load served by such exit. Capacity determined by allowing 0.30 sq. meter of net floor area per ambulatory occupant and 1.90 sq. meters per non-ambulatory occupant.
Exit enclosures: interior stairways/ramps/escalators must be enclosed (exceptions noted); walls: 2-hour fire-resistive.
Smokeproof enclosures: vestibule & continuous stairway enclosed by 2-hour fire-resistive walls (required for buildings ≥ 5 stories).
Exit outlets: discharge into a public way, exit court, or exit passageway with specified fire-resistance.
Exits illuminated with 10.7 LUX minimum at floor level.
Aisles: minimum widths specified; exit distances limited; cross aisles and vomitories must meet width requirements; slope limits.
Seats: Spacing and width dimensions.
Reviewing Stands, Grandstands, and Bleachers: specific design and safety requirements
Special Hazards:
- Boiler Rooms: every boiler room and every room containing an incinerator or liquefied petroleum gas or liquid fuel-fired equipment shall be provided with at least two (2) means of egress, one of which may be a ladder. All interior openings shall be protected as provided for in the Code.
- Cellulose Nitrate Handling: Film laboratories, projection rooms, and nitro-cellulose processing rooms shall have not less than two exits.

Skylights

Metal frames required (except for Group A/J); designed for roof loads; set above roof level.
Glass at < 45° above first story needs to be set at least 100 millimeters above the roof shall be set at least 100 millimeters above the roof.
Wired glass required (spacing limits noted), except for certain shafts (which need screens).
Photographer skylights: metal frames and plate glass OK.
Greenhouses: ordinary glass OK (height limits noted); wood frames outside restrictive fire zones allowed if height is within limit.

Bays, Porches, & Balconies

Walls/floors: conform to exterior walls/floors construction type.
Roof covering: conform to main roof requirements.
Exterior balconies attached to masonry walls: incombustible brackets/beams.
Railings needed for balconies/landings/porches > 750mm above grade.

Penthouses & Roof Structures

Height limits: 8.40m (tanks/elevators), 3.60m (other cases).
Area limits: aggregate area should be less than 1/3 of the supporting roof.
Prohibited uses: shelter only for mechanical equipment or vertical shaft openings.
Construction: walls, floors, roof as required for the main structure (some exceptions noted).
Towers and spires: exterior walls as required for the building; height and area limits.
Skeleton towers: must be incombustible if > 7.50m in height.

Chimneys, Fireplaces, & Barbecues

Chimneys: designed per engineering principles; capable of producing required draft.
Masonry chimney walls: specified thicknesses based on appliance type; liners required.
Linings: fire clay (thickness specified); extends from below inlet to above masonry walls.
Chimney passageway area: not smaller than vent connection.
Height: extends 600mm above the roof and any building part within 3.00m.
Clearance: distances to combustible materials specified.
Termination: incinerator chimneys must have spark arresters.
Cleanouts: required at the base of masonry chimneys.
Fireplaces/barbecues: solid masonry or reinforced concrete; minimum requirements specified.
Fireplace walls: thickness requirements; firebox depth specified.
Metal hoods: specs and distance from combustible materials noted.
Circulators: approved metal heat circulators allowed.
Smoke chamber: dimensions specified.
Area of flues/throats/dampers: requirements specified.
Lintel: non-combustible support over the fireplace opening.
Hearth: non-combustible slab dimensions specified.

Fire-Extinguishing Systems

Automatic fire-extinguishing systems required in:
- Stories/basements/cellars > $200 m^2$ used for habitation/recreation/dining/study/work with > 20 occupants.
- Dressing rooms/workshops/assembly halls (Group H/I) with > 10 or 500 occupants if exits are > 30m from a safe dispersal area.
- Rooms storing flammable films/articles.
Dry standpipes: required in buildings ≥ 4 stories; construction/testing specs; size based on water delivery capacity; location near stairways; Siamese connections required.
Wet standpipes: required for certain occupancies (Group H/I, etc.) ≥ 2 or 3 stories; construction materials noted; size based on water delivery capacity; testing procedures; locations specified.
Basement pipe inlets: required in stores/warehouses/factories with basements (exceptions noted); material and location specs.

Stages & Platforms

Stage ventilators: metal or incombustible, area ≥ 5% of stage floor area; spring action opening; glass protection; remote control; fusible links.
Gridirons: incombustible material; load support specified.
Accessory rooms: located on stage side of proscenium wall; fire-resistive separation.
Proscenium walls: 2-hour incombustible construction; extends above auditorium roof; openings protected by fire assemblies.
Stage floor: construction depends on occupancy type; load support specified.
Platforms: construction depends on occupancy; enclosed platforms must have ventilators.
Stage exits: at least one 900 mm wide exit from each side of stage to street/exit court; exit stair for fly galleries; two means of egress for dressing rooms.

Motion Picture Projection Rooms

General: applies to ribbon-type films > 22mm and electric projection equipment in certain occupancies.
Enclosure: a projection room must be large enough to permit the operator to walk freely on either side and back of the machine.
Construction: 1-hour fire-resistive throughout, incombustible finishes, height not less than 2.40 meters, floor area of not less than 7.00 sq. meters and 3.50 sq. meters for each additional machine.
Exit: at least two doorways separated by not less than one-third the perimeter of the room, each at least 750 millimeters wide and 2.00 meters high protected by a self-closing fire assembly having a three-fourth - hour fire-resistive rating
Ports & Openings: Specifications for ports and openings in projection room walls.
Ventilation: fresh air intake from the exterior of the building is required, as well as mechanical exhaust systems, which shall draw air from each arc lamp housing to out-doors.
Regulation of Equipment: All shelves, fixtures, and fixed equipment in a projection room shall be constructed of incombustible materials. All films not in actual use shall be stored in metal cabinets having individual compartments for reels or shall be in generally accepted shipping containers. No solder shall be used in the construction of such cabinets.

Lathing, Plastering, & Wall Boards

Installation follows fire-resistive rating requirements and the building's construction type.