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OBC 2009. CHAPTER FIVE GENERAL BUILDING HEIGHTS AND AREAS. OVERVIEW. REGULATES THE MINIMUM TYPE OF CONSTRUCTION AREA MODIFICATIONS HEIGHT MODIFICATIONS MEZZANINES REQUIREMENTS UNLIMITED AREAA STRUCTURES. PARKING GARAGES RELATED ISSUES. OBJECTIVES. USE TABLE 503
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OBC 2009 CHAPTER FIVE GENERAL BUILDING HEIGHTS AND AREAS
OVERVIEW • REGULATES THE MINIMUM TYPE OF CONSTRUCTION • AREA MODIFICATIONS • HEIGHT MODIFICATIONS • MEZZANINES REQUIREMENTS • UNLIMITED AREAA STRUCTURES. • PARKING GARAGES RELATED ISSUES.
OBJECTIVES • USE TABLE 503 • ADDITIONAL PROTECTION FEATURES TO MODIFY HEIGHTS AND AREAS.
ALLOWABLE AREA • ESSENTIALS TO DETERMINE THE ALLOWABLE AREAS: • TYPE AND AMOUNT OF COMBUSTIBLES DUE TO USE OF BUILDING • AMOUNT OF COMBUSTIBLES CONTAINED IN THE CONSTRUCTION OF A BUILDING • SPRINKLER, OPEN YARD, FIRE WALL
AREA LIMITATIONS • DETERMINE THE TABULAR AREA • MODIFY THE TABULAR AREA • MAXIMUM BUILDING AREA IS INTENDED TO LIMIT THE SIZE OF THE FIRE AND TO CONTROL THE SPREAD OF FIRE, LIFE SAFEY, ACCESS TO FIRE DEPARTMENT PERSONNEL. • MEZZANINE DOES NOT CONTRIBUTE TO BUILDING AREA • MAXIMUM ALLOWABLE AREA IS LIMITED TO ALLOWABLE AREA PER FLOOR MULTIPLIED BY THREE.
HOW DO WE DETERMINE THE CONSTRUCTION TYPE • 1. IDENTIFY THE USE • 2. IDENTIFY AREA AND HEIGHT • 3. DETERMINE THE CONSTRUCTION TYPE • NOTE: IF THE USE AND CONSTRUCTION TYPE ARE DEFINED BY THE DESIGN PROFESSIONAL THEN THE AREA AND HEIGHT LIMITATIONS WILL BE ESTABLISHED FROM TABLE 503
TABLE 503 • ALLOWABLE HEIGHT AND AREA • USE GROUP • CONSTRUCTION TYPE • NUMBER OF FLOORS • AREAS PER FLOOR • HEIGHT: # OF STORIES AND FEET ABOVE GRADE PLANE
EXAMPLES • M USE, IIB • AREA: • HEGHT: • # OF STORIES:
HEIGHTS MODIFICATIONS • 504 • SPRINKLER SYSTEM NFPA 13 • A MAXIMUM OF ONE STORY • A MAXIMUM ADDITIONAL HEIGHT OF 20 FEET. • R USES IS LIMITED TO FOUR STORIES AND 60 FEET IF NFPA 13R IS USED
EXAMPLE • B USE, IIB, NFPA 13 • 4 STORY • 75 FEET • AREA INCREASE
AREA INCREASE • 506 • Aa = At + {AtIf/100} + {AtIs/100} • Frontage and sprinkler increase • If = 100[F/P –0.25]W/30 • W Minimum 20 feet • Weighted average • If W > 30 USE 30 • W=60 IF ALL REQUIREMENTS OF 507 ARE MET EXCEPT 60 FOOT
AUTOMATIC SPRINKLER SYSTEM • 200 % FOR MULTISTORY STRUCTURES • 300 % FOR SINGLE STORY BUILDINGS. • SEE THREE EXCEPTIONS OF SECTION 506.3
MIXED USES508 OBC • INCIDENTAL USE AREAS • SEPARATED OR PROTECTED PER TABLE 508.2 • MIXED OCCUPANCIES 508.3 • ACCESSORY USE AREAS • NONSEPARATED • SEPARATED USES • TABLE 508.3.3 • 2007 CHANGES • 502.1, 202 DEFINITIONS OF BASEMENT AND STORY ABOVE GRADE PLANE. • TABLE 503 MODIFIED FOR H-5 USE. • 503.1.1 UNLIMITED HEIGHT AND AREA FOR SPECIAL INDUSTRIAL OCCUPANCY F-1 AND F-2 ONLY • MODIFICATION OF SECTION 504.2 HEIGHT INCREASE TO THE ENTIRE FIRE AREA
2007 CHANGES • AN ADDITION TO SECTION 505.2 FLOOR AREA OF MEZZANINE LIMITED TO 50% OF ROOM IN WHICH IT IS LOCATED TYPE I OR II, FYLLY SPRINKLERED, AND EMERGENCY VOICE/ALARM COMMUNICATION SYSTEM
2007 CHANGES • AN ADDITION TO SECTION 505.4 NEW EXCEPTION ALLOWES FOR TOTAL ENCLOSURE OF A MEZZANINE IF THERE ARE AT LEAST TWO MEANS OF EGRESS. • CLARIFICATIONS FOR ALLOWABLE AREA CALCULATIONS, 506.1, 506.2, 506.3
2007 CHANGES • CLARIFICATIONS TO SECTION 506.2.1 FOR If CALCULATIONS • MODIFICATION TO SECTION 506.4.1 ALLOWABLE AREA OF MIXED OCCUPANCY BUILDINGS. VERTICAL AND HORIZANTAL RATIOS.
2007 CHANGES • ADDITIONAL LANGUAGE TO SECTION 507.3 GROUP A OCCUPANCY LOCATED IN UNLIMITED AREA BUILDINGS.. FOUR CONDITIONS. • ADDITIONAL LANGUAGE TO REDUCE OPEN SPACE FOR UNLIMITED AREA BUILDINGS
2007 CHANGES • MODIFICATIONS TO SECTION 507.7 THAT DEAL WITH GROUP H OCCUPANCIES IN UNLIMITED AREA BUILDINGS. • CLARIFICATIONS TO SECTION 508.2 INCIDENTAL USE AREAS • CLARIFICATIONS TO SECTION 508.3 MIXED OCCUPANCIES SEVERAL SUBSECTIONS MODIFIED/CLARIFIED • TABLE 508.3.3 MODIFIED TO MAKE IT EASY TO USE
2007 CHANGES • 509.2 MODIFIED • 509.8 A NEW SECTION TO DEAL WITH GROUP B OR M THAT OCCUR BELOW AN OPEN PARKING STRUCUTRE
2009 CHANGES • 501.2 • 502.1 • 503 • 504 • 505 • 506 • 507 • 508 • 509