SECTION 3403.2.2.2
SECTION 34 – EXISTING STRUCTURES
3403.2.2.2 Structural alterations. When more than 30 percent, cumulative since
May 21, 1973, of the floor and roof areas of the building or structure have been or are
proposed to be involved in substantial structural alteration, the building or structure
shall comply with Section 3403.6. The areas to be counted towards the 30 percent
shall be those areas tributary to the vertical load carrying components (joists, beams,
columns, walls and other structural components) that have been or will be removed,
added or altered, as well as areas such as mezzanines, penthouses, roof structures
and infilled courts and shafts.
When such alterations involve only the lowest story of a wood frame building or
structure and Section 3405 does not apply, only the lateral force resisting
components in and below that story need comply with Section 3403.6.
COMMENT 1:
Name: CAC Structural Subcommittee
Date: March 5, 2003
Comments/Findings:
3403.2.2.2 Structural alterations. When more than 30 percent, cumulative since
May 21, 1973, of the floor and roof areas of the building or structure have been or are
proposed to be involved in substantial structural alteration, the building or structure
shall comply with Section 3403.6. The areas to be counted towards the 30 percent
shall be those areas tributary to the vertical load carrying components (joists, beams,
columns, walls and other structural components) that have been or will be removed,
added or altered, as well as areas such as mezzanines, penthouses, roof structures
and infilled courts and shafts.
EXCEPTIONS:
1. When such alterations involve only the lowest story of a Type V ((wood frame))
building or structure and Section 3405 does not apply, only the lateral force resisting
components in and below that story need comply with Section 3403.6, or
2. When such alterations involve the lowest story by of a Type V building or structure
of R3 occupancy and that floor’s current and proposed use is as a garage, that level
is exempt from Section 3403.2.2.2. Such alterations need not be counted as part of
the cumulative total of tributary area of structural alterations.
[Note: To clarify the code language on the seismic triggers when structural alterations
are performed in Type V building , to facilitate permit process and to provide
exemptions to minor structural alterations, such as removing posts, with no loss in
lateral force resisting capacity.
Recommend to be brought to full CAC committee for further action.]
Place an X in
one of the
following:
Retain as is:
Place an X in
one of the
following:
More
Restrictive:
Update as noted:
Revise:
Delete:
X
Less Restrictive:
Neither more nor less:
X
COMMENT 2:
Name: Hanson Tom - DBI
Date: May 1, 2003
Comments/Findings:
3403.2.2.2 Structural alterations. When more than 30 percent, cumulative since
May 21, 1973, of the floor and roof areas of the building or structure have been or are
proposed to be involved in substantial structural alteration, the building or structure
shall comply with Section 3403.6. The areas to be counted towards the 30 percent
shall be those areas tributary to the vertical load carrying components (joists, beams,
columns, walls and other structural components) that have been or will be removed,
added or altered, as well as areas such as mezzanines, penthouses, roof structures
and infilled courts and shafts.
EXCEPTIONS:
1. When such alterations involve only the lowest story of a Type V ((wood frame))
building or structure and Section 3405 does not apply, only the lateral force resisting
components in and below that story need comply with Section 3403.6, or
2. When such alterations involve the lowest story by of a Type V building or structure
of R3 occupancy and that floor’s proposed use is as a garage, that level is exempt
from Section 3403.2.2.2. Such alterations need not be counted as part of the
cumulative total of tributary area of structural alterations.
[Note: Editorial change of Comment No. 1, to allow conversion of storage to garage. ]
Place an X in
one of the
following:
Retain as is:
Place an X in
one of the
following:
More
Restrictive:
Update as noted:
Revise:
Delete:
X
Less Restrictive:
Neither more nor less:
X
COMMENT 3:
Name: Pat Buscovich, S. E.
Date: May 1, 2003
Comments/Findings:
Concur with Hanson Tom (Comment No. 2).
Place an X in
one of the
following:
Retain as is:
Place an X in
one of the
following:
More
Restrictive:
Update as noted:
Revise:
Delete:
X
Less Restrictive:
Neither more nor less:
X