Presented by:

Ara Sargsyan, PE, CBO, LEED AP

December 2015

California Building Code

Heights & Areas

Disclaimer:  This  presenta1on  was  developed  by  a  third  party  and  is  not  funded  by  WoodWorks  or  the  So=wood  Lumber  Board.  

“The  Wood  Products  Council”  is  a  Registered  Provider  with  The  American  Ins<tute  of  Architects  Con<nuing  Educa<on  Systems  (AIA/CES),  Provider  #G516.      Credit(s)  earned  on  comple<on  of  this  course  will  be  reported  to  AIA  CES  for  AIA  members.  Cer<ficates  of  Comple<on  for  both  AIA  members  and  non-­‐AIA  members  are  available  upon  request.      

This  course  is  registered  with  AIA  CES  for  con<nuing  professional  educa<on.  As  such,  it  does  not  include  content  that  may  be  deemed  or  construed  to  be  an  approval  or  endorsement  by  the  AIA  of  any  material  of  construc<on  or  any  method  or  manner  of  handling,  using,  distribu<ng,  or  dealing  in  any  material  or  product.  __________________________________

Ques<ons  related  to  specific  materials,  methods,  and  services  will  be  addressed  at  the  conclusion  of  this  presenta<on.    

 

Disclaimer  

The training materials and opinions presented at this webinar do not constitute official views of the author's employer and should not be used as such. Anyone who wants an official ruling by the Building Official should contact the local Building Department.

IBC is © by International Code Council

Course  Descrip/on  This session is intended for design professionals who want to better understand how to successfully design multi-story wood buildings in compliance with the 2013 California Building Code (CBC). Focusing on allowable heights and areas, it will cover Chapter 5 of the CBC using building examples that differ in terms of their occupancy groups, construction types (Type III, IV and V) and design elements (e.g., yard vs. no yard, mezzanine, etc.). Code sections that are commonly misinterpreted or overlooked will be discussed, as will changes to Chapter 5 of 2015 International Building Code (IBC) that will affect the 2016 CBC.

Learning  Objec/ves  

•  Consider 2013 California Building Code requirements and allowances related to building area and height limitations.

•  Discuss code provisions for mixed occupancy buildings of different construction types.

•  Determine effective methods of designing buildings with optimal floor area, number of stories, height and construction type.

•  Explore height and area requirement changes in the 2015 IBC.

•  Defini<ons  (502)  •  General  Height  and  Area  Limita<ons  (Table  503)  •  Building  Height  (504)  •  Mezzanines  and  Equipment  Pla\orms  (505)  •  Building  Area  Modifica<ons  (506)  •  Unlimited  Area  Buildings  (507)  •  Mixed  Use  and  Occupancy  (508)  •  Incidental  Uses  (509)  •  Special  Provisions  (510)  

Building  Height  and  Area  Limita/ons  

•   Grade  Plane      

•   Basement  

•   Story  Above  Grade  Plane  

•   Building  Height  

•   Mezzanine  

Defini/ons  

Grade  Plane  Defini/on  A  reference  plane  represen<ng  the  average  of  finished  ground  level  adjoining  the  building  at  exterior  walls.  Where  the  finished  ground  level  slopes  away  from  the  exterior  walls,  the  reference  plane  shall  be  established  by  the  lowest  points  within  the  area  between  the  building  and  the  lot  line  or,  where  the  lot  line  is  more  than  6  feet  from  the  building,  between  the  building  and  a  point  6  feet  from  the  building.  

30'-0"

5'-0" 5'-0" 5'-0" 5'-0" 5'-0" 5'-0"

Elev

. 12

'

Elev

. 12

'

Elev

. 12

'

Elev

. 4.

5' (

Ave

rage

)

Elev

. 2'

Elev

. 9.

5' (

Ave

rage

)42 31

56

12’+12’+12’+9.5’+4.5’+2’ 6

GPE = = 8.67’

Methods  of  Determining  the  Grade  Plane  

Weighted Average

30'-0"

15'-0" 10'-0" 5'-0"

1 2

3 4

Elev

. 12

'

Elev

. 2'

Elev

. 12

'

Elev

. 2'

Weighted Average

15’x12’ + 10’x(12’+2’)/2 + 5’x2’ 30’

GPE = = 8.67’

Methods  of  Determining  the  Grade  Plane  

Table503  

§  Installa<on  of  automa<c  sprinkler  system  with  accordance  to  Sec<on  903.3.1.1  (NFPA-­‐13)  allows  a  max.  increase  of:  

§ 20’  height  increase  to  allowable  height,  and  § 1  addi<onal  story  to  allowable  story  

§  For  Group  R2  buildings  of  Type  VA  construc<on,  max  allowable  increase:  

§ Restricted  to  total  building  height  no  more  than  60’    § Restricted  to  total  building  story  height  no  more  than  4  stories  § Height  increase  are  allowed  in  addi<on  to  floor  area  increase  in  accordance  to  Sec<on  506.3.  

Height  (504)    Automa/c  sprinkler  system  Increase  

§ For  Group  R3  buildings  max  allowable  increase:  § Height  +20  l    (no  more  than  60  l)  § Story    +1  (no  more  than  4  stories)  

(504)  2015  July  1st  Supplement  NFPA  13R  Automa/c  sprinkler  system  Increase                                

§ May  be  used  as  parking  cover:  § Maximum  40  l  x  150  l  Arrays    § Minimum  10  l  separa<on  (25  l  if  Driveway  aisle)  

(503)  2015  July  1st  Supplement  Excep/on  for  Solar  Photovoltaic  Panels  

§  In  other  than  Group  A,  E,H,  I,  L  and  R  occupancies,  high-­‐rise  buildings,  and  other  applica<ons  listed  in  Sec<on  1.11  regulated  by  the  Office  of  the  State  Fire  Marshal  (SMF),  these  increases  are  permined  in  addi<on  to  area  increase  in  accordance  with  Sec<on  506.3.  

A   R  L  E   I  H  High-­‐rise  Buildings  and  

Height  (504)    Automa/c  sprinkler  system  Increase  

§  Buildings  with  an  Occupancy  Group  I-­‐2  of  Type  IIB,  III,  IV  or  V  construc<on.  

§  Buildings  with  an  Occupancy  Group  H-­‐1,  H-­‐2,  H-­‐3  or  H-­‐5.  §  Fire-­‐resistance  ra<ng  subs<tu<on  in  accordance  with  Table  

601,  Note  d.  §  Buildings  with  an  Occupancy  Group  L.  §  Buildings  with  licensed  Group  R-­‐2.1  or  R-­‐4  

Height  Increase  Not  Allowed  (504.2)  

2 9,500

Table503   55’+20’=75’ 2+1=3

Automatic Sprinkler System – Height Increase

3 12,000

Table503   50’+20’=70’ 3+1=4

OK Area Increase for Fire Sprinklers

Automatic Sprinkler System – Height Increase

60’ (504.2)

3 21,000

Table503   50’+20’=70’ 3+1=4

OK Area Increase for Fire Sprinklers

Automatic Sprinkler System – Height Increase

Aa  =  {At  +  [At  x  If]  +[At  x  Is]}    (Equa<on  5-­‐1)  

§  Equa<on  for  determining  allowable  area  per  story  Aa  (sq.  l)  §  Tabular  area  per  story  as  per  Table  503  (At)  §  Area  increase  due  to  frontage  (If)  §  Area  increase  due  to  installa<on  of  sprinkler  system  (Is)  

§  Single  basement  need  not  be  included  in  total  allowable  area    §  basement  does  not  exceed  the  permined  area  for  a  building  with  no  more  

than  one  story  above  grade  plane  §  No  more  than  one  basement  level  may  be  considered  as  not  contribu<ng  

to  the  total  building  area.    All  area  in  the  other  basement  levels  must  be  included  in  total  building  area  count.  

Area  Modifica/on  (506)  

§  Applicable  to  buildings  with  more  than  25%  of  perimeter  fron<ng  on  a  public  way  or  open  space  with  minimum  20’  in  width.  

     If  =  [F/P  –  0.25]W/30  –  I  f  =  Area  increase  due  to  frontage.  –  F  =  Building  perimeter  that  fronts  on  a  public  way  or  open  space  having  20  feet  (6096  mm)  open  minimum  width  (feet).  

–  P  =  Perimeter  of  en<re  building  (feet).  – W  =  Width  of  public  way  or  open  space  (feet)  in  accordance  with  Sec<on  506.2.1.  

Area  Increase  Due  to  Frontage  (506.2)  

If = [F/P – 0.25]W/30

App

rove

d Fi

re L

ine

Open space shall be either on the same lot or dedicated for public use and shall be accessed from a street or approved fire line (506.2.2)

South Ave (60')

Wes

t St

(60'

)

120'

New Building

60'

60'50' 30

'

20'

10'

70'

20'

10' 40'

30'

10'

30'

10'

60'

20'20' 40'

Existing Building

P.L.

P.L.

P.L.

P.L.

N

Area  Increase  Due  to  Frontage  (506.2)  

If ≤ 0.75

Area  Increase  Due  to    Frontage    (Building  does  not  comply  with  506.2.1  Excep/on)  

If = [F/P – 0.25]W/30 =

20x(20+30)/2+80x30+30x20+60x30+20x30+20x(20+30)/2+5x(20+30)/2+10x30+50x30

20+80+30+60+20+20+5+10+50 W=

8325

295 W= = 28.22’

F = 295’

P = 340’

= [295/340 – 0.25] 28.22/30

If = 0.58

South Ave (60')

Wes

t St

(60'

)

120'

New Building

60'

60'50' 30

'

20'

10' 20

' 30'

70'

20' 20' 80' 20'

10' 5' 20'

30'

10'

30'

5'

20'

20'

20'

20'

Existing Building

P.L.

P.L.

P.L.

P.L.

N

South Ave (60')

Wes

t St

(60'

)

120'

New Building

60'

60'50' 30

'

20'

10' 20

'

60' 70

'

20' 80' 20' 20'

10' 5' 20'

30'

10'

30'

5'

20'

20'

20'

60'

20'20' 40'

Existing Building

P.L.

P.L.

P.L.

P.L.

N If < 1.5

If = [F/P – 0.25]W/30 =

80x(20+60)/2+20x60+30x20+40x60+20x(60+50)/2+20x60+20x(30+20)/2+5x(20+30)/2+10x60+50x60

80+20+30+60+20+20+5+10+50 W= 13925

295 W= = 47.20’

F = 295’

P = 340’

= [295/340 – 0.25] 47.20/30

If = 0.97

Area  Increase  Due  to    Frontage    (Building  complies  with  506.2.1  Excep/on)  

§  When  a  building  is  equipped  with  automa<c  sprinkler  system  as  per  Sec<on  903.3.1.1  (NFPA-­‐13),  the  area  limita<on  per  Table  503  is  permined  to  be  increased  as  followed:  

§  Increase  by  200%,  Is  =  2  for  mul<-­‐story  buildings  §  Increase  by  300%,  Is=  3  for  single-­‐story  buildings  

§  In  other  than  high-­‐rise  buildings,  Group  A,  E,H,  I,  L  and  R  occupancies  or  other  applica<ons  listed  in  Sec<on  1.11  regulated  by  SFM  Area  increase  allowed  in  addi<on  to  height  and  story  increases  

   §  For  Group  R2  buildings  of  Type  VA  construc<on,  the  area  

increase  allowed  in  addi<on  to  height  and  story  increases    

Area  Increase  Due  to  Automa/c  Sprinklers  (506.3)  

Sprinklers  system  shall  not  be  used  to  increase  the  area  for  the  following  condi<ons:  

§  Buildings  with  an  occupancy  in  Use  Group  H-­‐1.  §  The  floor  area  of  an  occupancy  in  Use  Group  H-­‐2  or  H-­‐3.    

§  For  mixed-­‐use  buildings  containing  such  occupancies,  the  allowable  area  shall  be  calculated  as  separated  occupancy  per  Sec<on  508.3.3.2,  with  the  sprinkler  increase  applicable  only  to  the  por<ons  of  the  building  not  classified  as  Use  Group  H-­‐2  or  H-­‐3.  

§  Fire-­‐resistance  ra<ng  subs<tu<on  as  per  Table  601,  Note  d.  §  [SFM]  Buildings  in  Group  L  occupancies.  

Excep/ons  to  Area  Increase  (506.3)  

§  For  Group  A,  E,H,  I,  L  and  R  occupancies,  high-­‐rise  buildings,  or  other  applica<ons  listed  in  Sec<on  1.11  regulated  by  SFM  

§  For  building  >1  story  above  grade  plane,  mul<ply  Aa  by  2.  §  No  story  shall  exceed  Aa  for  the  occupancies  on  that  story  

§  For  other  than  Group  A,  E,H,  I,  L  and  R  occupancies,  high-­‐rise  buildings,  or  other  applica<ons  listed  in  Sec<on  1.11  regulated  by  SFM  

§  For  building  2  stories  above  grade  plane,  mul<ply  Aa  by  2  §  For  building  >2  stories  above  grade  plane,  mul<ply  by  Aa  by  3.    §  No  story  shall  exceed  Aa  for  the  occupancies  on  that  story.  

Area  Determina/on  (506.4)  Total  Building  Allowable  Area  (for  single  occupancy  group)  

Aa  shall  be  based  on  most  restric<ve  provision  for  each  occupancy  when  the  mixed  occupancies  are  treated  as  nonseparated  occupancy  (508.3.2)  

“Most  Restric<ve”  

Nonseparated  …  

Area  Determina/on  Mixed  Occupancies  (506.4.1)  

Table503   “Most Restrictive”

 In  each  story,  the  building  area  shall  be  such  that  the  sum  of  the  ra<os  of  the  actual  floor  area  of  each  occupancy  divided  by  the  allowable  area  of  each  occupancy  shall  not  exceed  one.  (508.3.3)    

Actual area

Allowable area (Aa) + ≤ 1 for each floor

Actual area

Allowable area (Aa) + …

Area  Limita/ons-­‐  Mixed  Occupancies  Separated…  Each  story…  (508.4.2)  

 For  other  than  Group  A,  E,H,  I,  L  and  R  occupancies,  high-­‐rise  buildings,  or  other  applica<ons  listed    in  Sec<on  1.11  regulated  by  SFM,  the  sum  shall  not  exceed  2  for  2-­‐stories  building  and  3  for  buildings  3-­‐stories  or  higher    

Actual area

Allowable area (Aa) + ≤ 2 for 2-stories building

Actual area

Allowable area (Aa) + …

Actual area

Allowable area (Aa) + ≤ 3 for 3-stories building or

higher

Actual area

Allowable area (Aa) + …

Area  Limita/ons-­‐  Mixed  Occupancies  Separated…  En/re  Building…  (506.5)  

For  Group  A,  E,H,  I,  L  and  R  occupancies,  high-­‐rise  buildings,  or  other  applica<ons  listed    in  Sec<on  1.11  regulated  by  SFM,  the  sum  shall  not  exceed  2  for  buildings  2  stories  or  higher.  

Actual area

Allowable area (Aa) + ≤ 2 for 2-stories building or higher

Actual area

Allowable area (Aa) + …

Area  Limita/ons-­‐  Mixed  Occupancies  Separated…  En/re  Building…  (506.5)    

•  Nonsprinklered,  one  story  (F-­‐2,  S-­‐2)  •  Sprinklered,  one  story  (B,  F,  M,  S  and  A-­‐4-­‐  no  Type  V)  •  Mixed  occupancy  buildings  with  Groups  A-­‐1  and  A-­‐2  

•  Not  for  Type  V  construc<on  •  A-­‐1  and  A-­‐2  Occupancy  separa<on  per  Sec.  508.4.4  •  A-­‐1  and  A-­‐2  Area  limita<ons  per  Sec.  503.1  •  Exit  doors  from  A-­‐1  and  A-­‐2  directly  to  exterior  

•  Sprinklered,  two  story  (B,  F,  M,  S)  •  Sprinklered,  one  story  (A-­‐3,  Type  II)  

•  Use  limita<ons,  No  stage  •  Sprinklered,  one  story  (A-­‐3,  Types  III  and  IV)  

•  Use  limita<ons,  No  stage,  Exit  within  21  inches  from  Grade  

 

Unlimited  Area  Buildings  (507)  

•  H-­‐2,  H-­‐3  and  H-­‐4  within  F  and  S  •  Restric<ons  on  Area,  Occupancy  Separa<on,  Use,  Height  &  Loca<on  within  Building.  

•  Aircral  paint  hangar  (H-­‐2)  complying  with  Sec.  412.6  •  Group  E  buildings  (Type  II,  IIIA  or  IV)  

•  Two  exits  from  each  classroom  •  Mo<on  picture  theaters    (A-­‐1)Type  II    •  Covered  and  open  mall  buildings  and  anchor  buildings  complying  with  Sec.  402  

•  60  l  wide  Yards-­‐  Open  Space  •  Reduced  Open  Space  /  Restric<ons    

Unlimited  Area  Buildings  (507)  

•  Accessory  Occupancies  •  Aggregate  Area  Limita<on-­‐  10%  per  floor  •  To  be  Individually  Classified  per  Sec.  302.1  •  Allowable  building  area  and  height  •  No  Occupancy  Separa<on  Required  (Some  Excep<ons)    

•  Nonseparated  Occupancies  •  Allowable  building  area  and  height  •  No  Occupancy  Separa<on  Required  (Some  Excep<ons)  

Mixed  Occupancies  (508)  

•  Each  separated  occupancy  shall  comply  with  the  building  height  limita<ons  based  on  the  type  of  construc<on  of  the  building  in  accordance  with  Sec<on  503.1.  •  Excep<on:  Special  provisions  permined  by  Sec<on  510.  

•  Individual  occupancies  shall  be  separated  from  adjacent  occupancies  as  per  Table  508.4  •  Required  separa<ons  shall  be  fire  barriers  constructed  as  per  Sec<on  707  or  horizontal  assemblies  constructed  as  per  Sec<on  711,  or  both,  so  as  to  completely  separate  adjacent  occupancies.  

Separated  Occupancies  (508.4)  

•  Incidental  uses  located  within  single  occupancy  or  mixed  occupancy  buildings  are  ancillary  func<ons  associated  with  a  given  occupancy  that  generally  pose  a  greater  level  of  risk  to  that  occupancy  and  are  limited  to  those  uses  listed  in  Table  509.  •  Excep<on:  Incidental  uses  within  a  dwelling  unit  

•  Area  Limita<on  –  10%  of  Building  area  of  the  story  •  Separa<on  and  Protec<on  per  Table  509  •  Protec<on  Limita<on  when  using  a  Sprinkler  System  

 

Incidental  Uses  (509)  

•  Horizontal  building  separa<on  allowance  •  Group  S-­‐2  enclosed  parking  garage  with  Group  S-­‐2  open  parking  garage  above  

•  Group  S-­‐2  Parking  (Type  I  any  or    Type  IV  open)  beneath  Group  R.  

•  Group  R-­‐1  and  R-­‐2  buildings  of  Type  IIIA  construc<on  •  6  stories,  75  l  high,  2-­‐hr  fire  walls  separa<ng  3,000  sq.  l.    

•  Group  R-­‐1  and  R-­‐2  buildings  of  Type  IIA  construc<on  •  9  stories,  100  l  high,  50  l  from  Lot  Line  or  other  Building  

•  Open  parking  garage  beneath  Groups  A,  I,  B,  M  and  R  •  Garage  levels  included  in  number  stories  

Special  provisions  (510)  

•  Open  parking  garage  beneath  Groups  A,  I,  B,  M  and  R  •  Garage  levels  included  in  number  stories  

•  Group  B  or  M  with  Group  S-­‐2  open  parking  garage  •  B  and  M  are  located  at  1st  story  only  •  Other  limita<ons  

•  Mul<ple  buildings  above  a  horizontal  assembly  •  With  S-­‐2  parking  below  or  Per  510.2,  510.3  or  510.8  •  shall  be  regarded  as  separate  and  dis<nct  buildings  from  each  other  and  shall  comply  with  all  other  provisions  of  this  code  as  applicable  to  each  separate  and  dis<nct  building.  

Special  provisions  (510)  

Building  Height  and  Area  Limita/ons    2013  CBC  vs  2012  IBC  

1  

1  

2  

2  

216,000

48,000

144,000

96,000

48,000

0

50,000

100,000

150,000

200,000

250,000

IBC CBC Option # 1 CBC Option # 2 IBC CBC

Type III-A, R2 Occup. NFPA 13 Type III-A, R2 Occup. NFPA 13R

4/65 4/65 5/85 5/85 4/65

Building  Height  and  Area  Limita/ons    2013  CBC  vs  2012  IBC  (Chart  1)  

4/70 4/60 4/60 3/50

108,000

72,000

48,000

24,000

0

20,000

40,000

60,000

80,000

100,000

120,000

IBC CBC IBC CBC

Type V-A, R2 Occup. NFPA 13 Type V-A, R2 Occup. NFPA 13R

Building  Height  and  Area  Limita/ons    2013  CBC  vs  2012  IBC  (Chart  2)  

Height  and  Area  Limita/ons  2015  IBC  Update      

2012  IBC    •  Single  Table  for  Maximum  Building  Height  (NS),  Number  of  Stories  (NS)  and  Allowable  Building  Area  (NS)  

Table  503  

2015  IBC    •  Separate  Dis<nct  Tables  for  Maximum  Building  Height  (S/NS),  Number  of  Stories  (S/NS)  and  Allowable  Area  Factor  (NS/S1/SM/S13R)  

Table  504.3  Table  504.4  Table  506.2  

   

 

Height  and  Area  Limita/ons  2015  IBC  Update      

2012  IBC    •  Building  Area  Modifica<ons  

 Aa  =  {At  +  [At  ×  If]  +  [At  ×  Is]}  

         

Equa<on  5-­‐1  

2015  IBC    •  Single  Occupancy,  1  story  

Aa  =  At  +  (NS  ×  If)  •  Single  Occupancy,  Mul<  story  Aa  =  [At  +  (NS  ×  If)]  ×  Sa  

•  Mixed  Occupancy,  Mul<  story  

Aa  =  [At  +(NS  ×  If)]    

Equa<ons  5-­‐1,  5-­‐2  &  5-­‐3    

Height  and  Area  Limita/ons  2015  IBC  Update      

2012  IBC    510.2  Horizontal  building  separa<on  allowance.    

Condi<on  2:    The  building  below  the  horizontal  assembly  is  not  greater  than  one  story  above  grade  plane.  

2015  IBC    510.2  Horizontal  building  separa<on  allowance.        Condi<on  2    is  Removed    

Ques/ons?  

This  concludes  The  American  Ins<tute  of  Architects  Con<nuing  Educa<on  Systems  Course  

Ara  Sargsyan,  PE,  CBO,  LEED  AP  www.ara4help.com  ara@ara4help.com