california building code heights & areas...learningobjec/ves • consider 2013 california...
TRANSCRIPT
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 [email protected]