Section 675IAC13-2.6-18. Chapter 16; structural design

   Chapter 16 is amended as follows: (a) Amend Section 1603, Construction documents, by deleting the text and inserting to read as follows: See the General Administrative Rules (675 IAC 12-6), Industrialized Building Systems (675 IAC 15), and local ordinance.

  (b) Amend Table 1604.5, Risk Category of Buildings and Other Structures, in Risk Category III under "Nature of Occupancy", in the second item, delete "occupa" and insert "occupant".

  (c) Amend Section 1604.6, In-situ load tests, by deleting the last sentence without substitution.

  (d) Amend Section 1604.8.2, Structural walls, by deleting "1.4.4" and inserting "1.4.5".

  (e) Amend Section 1606.1, General, by deleting "1602.1" and inserting "202".

  (f) Amend TABLE 1607.1, MINIMUM UNIFORMLY DISTRIBUTED LIVE LOADS AND MINIMUM CONCENTRATED LIVE LOADS item 26, Roofs as follows:

(1) Delete the word "Where".

(2) Delete the word "are" after "members".

(3) Delete ", at" after "floor".

(4) Delete "s" in the word "single" and insert "S".

(5) Delete ": Over" after "roofs" and insert "over".

(6) Delete the text of footnote "g" and insert to read as follows: g. Where snow loads occur that are in excess of the design conditions, the structure shall be designed to support the loads due to the increased loads caused by drift buildup or a greater snow design determined by the registered design professional or the owner if a registered design professional is not required by the General Administrative Rules (675 IAC 12-6) or the rules for Industrialized Building Systems (675 IAC 15) (see Section 1608). For occupiable roofs, see Section 1607.12.3.

(7) Delete the text of footnote "l" and insert to read as follows: l. Areas of occupiable roofs, other than roof gardens and assembly area, shall be designed to support the loads as required for the intended occupancy or use. The registered design professional, or owner if a registered design professional is not required by 675 IAC 12 or 675 IAC 15, shall certify in writing to the code official that the design provides the required support. Unoccupied landscaped areas of roofs shall be designed in accordance with Section 1607.12.3.1.

  (g) Amend Section 1607.8.1, Handrails and guards, by deleting Exception 1 without substitution.

  (h) Amend Section 1607.8.2, Grab bars, shower seats, and dressing room bench seats, by deleting "seat systems" and inserting "seats".

  (i) Amend Section 1608.2, Ground snow loads, by deleting the text and inserting to read as follows: The ground snow loads to be used in determining the design snow loads for roofs shall be determined in accordance with ASCE 7 and Table 1608.2.

  (j) Delete Table 1608.2, Ground Snow Loads, p_g, for Alaskan Location, without substitution.

  (k) Delete Figure 1608.2, Ground Snow Loads, p_g, for the United States (psf), and insert to read as follows: Table 1608.2, Ground Snow Loads (p_g) and Minimum Foundation Depth by County

NO	COUNTY	SNOW (pg) (PSF)1	FOUNDATION2 (inches)
1	Adams	20	36
2	Allen	20	36
3	Bartholomew	20	24
4	Benton	20	36
5	Blackford	20	30
6	Boone	20	30
7	Brown	20	24
8	Carroll	20	36
9	Cass	20	36
10	Clark	20	24
11	Clay	20	24
12	Clinton	20	30
13	Crawford	20	24
14	Daviess	20	24
15	Dearborn	20	24
16	Decatur	20	24
17	Dekalb	30	36
18	Delaware	20	30
19	Dubois	20	24
20	Elkhart	30	36
21	Fayette	20	30
22	Floyd	20	24
23	Fountain	20	24
24	Franklin	20	24
25	Fulton	30	36
26	Gibson	20	24
27	Grant	20	30
28	Greene	20	24
29	Hamilton	20	30
30	Hancock	20	30
31	Harrison	20	24
32	Hendricks	20	30
33	Henry	20	30
34	Howard	20	30
35	Huntington	20	36
36	Jackson	20	24
37	Jasper	30	36
38	Jay	20	30
39	Jefferson	20	24
40	Jennings	20	24
41	Johnson	20	30
42	Knox	20	24
43	Kosciusko	30	36
44	LaGrange	30	36
45	Lake	30*	36
46	LaPorte	30*	36
47	Lawrence	20	24
48	Madison	20	30
49	Marion	20	30
50	Marshall	30	36
51	Martin	20	24
52	Miami	20	36
53	Monroe	20	24
54	Montgomery	20	30
55	Morgan	20	30
56	Newton	30	36
57	Noble	30	36
58	Ohio	20	24
59	Orange	20	24
60	Owen	20	24
61	Parke	20	30
62	Perry	20	24
63	Pike	20	24
64	Porter	30*	36
65	Posey	20	24
66	Pulaski	30	36
67	Putnam	20	30
68	Randolph	20	30
69	Ripley	20	24
70	Rush	20	30
71	St. Joseph	30*	36
72	Scott	20	24
73	Shelby	20	30
74	Spencer	20	24
75	Starke	30	36
76	Steuben	30	36
77	Sullivan	20	24
78	Switzerland	20	24
79	Tippecanoe	20	30
80	Tipton	20	30
81	Union	20	30
82	Vanderburgh	20	24
83	Vermillion	20	30
84	Vigo	20	24
85	Wabash	20	36
86	Warren	20	30
87	Warrick	20	24
88	Washington	20	24
89	Wayne	20	30
90	Wells	20	36
91	White	20	36
92	Whitley	20	36
1. Snow is minimum ground snow load (pg) in pounds per square foot.
*Indicates those counties Lake, LaPorte, Porter, St. Joseph with extreme variation and shall require investigation by the design professional, or owner when a design professional is not required, to determine the actual minimum ground snow load at each site; however, the determined minimum snow load (pg) shall be at least thirty (30) pounds per square foot. Ground snow load determination for such counties shall be based on an extreme value statistical analysis of data available in the vicinity of the site using a value with a two percent annual probability of being exceeded (50-year mean recurrence interval).
2. Foundation is the minimum foundation depth to bottom of footing from the top of the grade above the footing in inches.

  (l) Amend Section 1609.1.2.1, Louvers, by deleting "54" and inserting "540".

  (m) Amend Table 1609.6.2, Net Pressure Coefficients as follows:

(1) Amend item 3 under "Flat<Slope<6:12 (27^o), Positive, 100 square feet or more, under "Partially enclosed", by deleting "10.72" and inserting "0.72".

(2) Amend item 4, by deleting "=" in the first line before "60 feet" and inserting "≤" and insert "ASCE 7" after "(Zone 4)". In the sixth line, delete "30.8-1" and insert "30.6-1".

(3) Amend item 5, by deleting "Zone 5" in the sixth line and inserting "Zone 4" and deleting "30.8-1" and inserting "30.6-1".

  (n) Amend Section 1611.1, Design rain loads, by adding a sentence after "weather data" to read as follows: See the Indiana Plumbing Code (675 IAC 16) for other roof drainage requirements.

  (o) Amend Section 1611.3, Controlled drainage, by adding a second paragraph to read as follows: See the Indiana Plumbing Code (675 IAC 16) for other roof drainage requirements.

  (p) Amend Section 1612.1, General, by deleting "in Section 1612.3" in the first sentence and inserting "by local ordinance".

  (q) Delete Section 1612.3, Establishment of flood hazard areas, without substitution.

  (r) Amend Section 1612.3.1, Design flood elevations, by deleting "in Section 1612.3" in the first sentence and inserting "by local ordinance".

  (s) Delete the figures 1613.3.1(1) through 1613.3.1(6) without substitution.

  (t) Amend Section 1613.3.4, Design spectral response acceleration parameters, by adding an exception to read as follows: Exception: For other than H and E occupancies, the maximum values of S_DS and S_D1 need not exceed the values in Table 1613.3.4.

  (u) Add TABLE 1613.3.4 MAXIMUM VALUES FOR S_DS AND S_D1 to read as follows:

Site Class	SDS	SD1
A	0.30	0.12
B	0.38	0.15
C	0.45	0.25
D	0.55	0.32
E	0.75	0.50
F	Note 1	Note 1
Note 1: Site-specific geotechnical investigation and dynamic site response analyses shall be performed to determine appropriate values.

  (v) Amend Section 1613.3.5, Determination of seismic design category as follows:

(1) Add an exception to read as follows: Exception: For other than H and E occupancies, the seismic design category need not exceed Seismic Design Category C for buildings and structures in Risk Category Groups I, II, and III for Class 1 buildings and structures.

(2) Delete "1613.5.5(2)" and insert "1613.3.5(2)".

(3) In the last line after "structure," insert "T".

  (w) Add a new Section 1613.5, Existing buildings, to read as follows:

(1) Additions, alterations, modifications, or changes of occupancy shall be in accordance with this section. Existing buildings shall be analyzed to the loads required by the code in effect at the time the building was constructed.

(2) Add a new subsection 1613.5.1 to read as follows: 1613.5.1 Additions to existing buildings. An addition that is structurally independent from an existing structure shall be designed and constructed with the seismic requirements for new structures. An addition that is not structurally independent from an existing structure shall be designed and constructed such that the entire structure conforms to the seismic-force-resistance requirements for new structures unless the following conditions are satisfied:

1. The addition conforms with the requirements for new structures,

2. The addition does not increase the seismic forces in any structural element of the existing structure by more than 10 percent cumulative since the original construction, unless the element has the capacity to resist the increased forces determined in accordance with generally accepted engineering practices such as ASCE 7, using professional structural engineering computer software, and

3. Addition does not decrease the seismic resistance of any structural element of the existing structure by more than 10 percent cumulative since the original construction, unless the element has the capacity to resist the forces determined in accordance with generally accepted engineering practices such as ASCE 7, using professional structural engineering computer software. If the building's seismic base shear capacity has been increased since the original construction, the percent change in base shear may be calculated relative to the increased value.

  (x) Add a new subsection 1613.5.2 to read as follows: 1613.5.2 Alterations. Alterations are permitted to be made to any structure without requiring the structure to comply with Section 1613, provided the alterations conform to the requirements for a new structure. Alterations that increase the seismic force in any existing structural element by more than 10 percent cumulative since the original construction or decrease the design strength of any existing structural element to resist seismic forces by more than five percent cumulative since the original construction shall not be permitted unless the entire seismic-force-resisting system is determined to conform generally accepted engineering practices such as ASCE 7, using professional structural engineering computer software for a new structure. If the building's seismic base shear capacity has been increased since the original construction, the percent change in base shear may be calculated relative to the increased value.

Exception: Alterations to existing structural elements or additions of new structural elements that are not required by generally accepted engineering practices such as ASCE 7, using professional structural engineering computer software and are initiated for the purpose of increasing the strength or stiffness of the seismic-force-resisting system of an existing structure need not be designed for forces conforming to generally accepted engineering practices such as ASCE 7, using professional structural engineering computer software, provided that an engineering analysis is submitted indicating the following:

1. The design strength of existing structural elements required to resist seismic forces is not reduced.

2. The seismic force to required existing structural elements is not increased beyond their design strength.

3. New structural elements are detailed and connected to the existing structural elements as required by Chapter 16.

4. New or relocated nonstructural elements are detailed and connected to existing or new structural elements as required by Chapter 16.

5. The alterations do not create a structural irregularity as defined by generally accepted engineering practices such as ASCE 7, using professional structural engineering computer software or make an existing structural irregularity more severe.

6. The alterations do not result in the creation of an unsafe condition.

  (y) Add a new subsection 1613.5.3 to read as follows: 1613.5.3 Change of occupancy. When a change of occupancy results in a structure being reclassified to a higher occupancy category, the structure shall conform to the seismic requirements for the higher occupancy category.

Exceptions: 1. Specific seismic detailing requirements of this code for a new structure shall not be required to be met where it can be shown by generally accepted engineering practices such as ASCE 7, using professional structural engineering computer software that the level of performance and seismic safety is equivalent to that of a new structure. Such analysis shall consider the regularity, overstrength, redundancy, and ductility of the structure within the context of the existing and retrofit (if any) detailing provided.

2. When a change of use results in a structure being reclassified from Risk Category I or II to Risk Category III and the structure is located in a seismic map area where SDS < 0.33, compliance with the seismic requirements of this code are not required.

(Fire Prevention and Building Safety Commission; 675 IAC 13-2.6-18; filed Aug 1, 2014, 11:12 a.m.: 20140827-IR-675130339FRA, eff Dec 1, 2014)