1. OBC 2009 CHAPTER FIVE GENERAL BUILDING HEIGHTS AND AREAS

2. OVERVIEW • REGULATES THE MINIMUM TYPE OF CONSTRUCTION • AREA MODIFICATIONS • HEIGHT MODIFICATIONS • MEZZANINES REQUIREMENTS • UNLIMITED AREAA STRUCTURES. • PARKING GARAGES RELATED ISSUES.

3. OBJECTIVES • USE TABLE 503 • ADDITIONAL PROTECTION FEATURES TO MODIFY HEIGHTS AND AREAS.

4. 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

5. 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.

6. 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

7. TABLE 503 • ALLOWABLE HEIGHT AND AREA • USE GROUP • CONSTRUCTION TYPE • NUMBER OF FLOORS • AREAS PER FLOOR • HEIGHT: # OF STORIES AND FEET ABOVE GRADE PLANE

8. EXAMPLES • M USE, IIB • AREA: • HEGHT: • # OF STORIES:

9. 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

10. EXAMPLE • B USE, IIB, NFPA 13 • 4 STORY • 75 FEET • AREA INCREASE

11. 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

12. AUTOMATIC SPRINKLER SYSTEM • 200 % FOR MULTISTORY STRUCTURES • 300 % FOR SINGLE STORY BUILDINGS. • SEE THREE EXCEPTIONS OF SECTION 506.3

13. 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

14. 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

15. 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

16. 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.

17. 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

18. 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

19. 2007 CHANGES • 509.2 MODIFIED • 509.8 A NEW SECTION TO DEAL WITH GROUP B OR M THAT OCCUR BELOW AN OPEN PARKING STRUCUTRE

20. 2009 CHANGES • 501.2 • 502.1 • 503 • 504 • 505 • 506 • 507 • 508 • 509