Plan Review: 213 Issues Found

Summary: The structural general notes on S105 delegate the design of lateral brace connections to the steel fabricator, specifying they must be engineered for the 'AXIAL FORCES SHOWN IN THE ELEVATIONS'. This delegated design requirement is reinforced by S301 Detail 6, which directs the fabricator to ensure components are 'SIZED FOR BRACE LOADS'. However, every lateral bracing member in the S105 elevatio...

Why it matters: Without actual factored or unfactored axial loads (Tension and Compression), the steel fabricator cannot design the gusset plates, weld sizes, clevises, or bolt configurations. This missing/conflicting information will halt steel detailing and fabrication until the Engineer of Record provides the...

Suggested next step: General notes on S105 and details on S301 require the fabricator to design lateral brace connections based on the axial forces shown in the elevations. However, all brace elevations on S105 indicate a placeholder load of '(0k T or C)'. Please provide the actual required axial ...

RFI draft: General notes on S105 and details on S301 require the fabricator to design lateral brace connections based on the axial forces shown in the elevations. However, all brace elevations on S105 indicate a placeholder load of '(0k T or C)'. Please prov...

Summary: The Foundation Plan shows the top of footings on the east side of the building stepping up significantly (e.g., footings near Grid 8 are at 2185'-8"). However, Lateral Brace Elevation E (5/S105), which spans across the building to Grid 8, depicts a flat Level 00 Slab at 2172'-2" and shows the steel column at Grid 8 extending down past this lower slab to a footing below. This creates a direct ve...

Why it matters: If the steel columns are detailed and fabricated according to the Lateral Brace Elevation, the columns on the east side of the building will be approximately 13 feet too long. This will cause severe constructability issues and clashes with the actual stepped concrete foundation.

Suggested next step: Please clarify the foundation and column base elevations for the lateral brace frames on the east side of the building. Should Lateral Brace Elevation E (5/S105) be updated to reflect the stepped footings at 2185'-8" shown on the Foundation Plan?

RFI draft: Please clarify the foundation and column base elevations for the lateral brace frames on the east side of the building. Should Lateral Brace Elevation E (5/S105) be updated to reflect the stepped footings at 2185'-8" shown on the Foundation Plan?

Summary: On the S101 framing plan, horizontal framing members (e.g., W12X14 [12]) run parallel to the indicated horizontal deck span and have single-number shear stud callouts, designating them as 'Beams' per the legend. Vertical framing members (e.g., W12X26 [9,0,3,6]) run perpendicular to the deck span and have multiple-number shear stud callouts, designating them as 'Girders' per the legend. However,...

Why it matters: This is a critical structural conflict. The shear stud layout details assume an inverted orientation of the deck flutes relative to the steel framing. Shear studs for beams running parallel to the deck span cannot be placed 'in each rib of the steel deck' as dictated by Detail 7, and studs on gir...

Suggested next step: Please clarify the deck span direction relative to the beams and girders. Should the S302 typical details 6 and 7 have their 'DECK SPAN IS...' notes swapped to match the orientations shown on the S101 framing plan?

RFI draft: Please clarify the deck span direction relative to the beams and girders. Should the S302 typical details 6 and 7 have their 'DECK SPAN IS...' notes swapped to match the orientations shown on the S101 framing plan?

Summary: The Level 00 Annotation Plan (A110) locates the elevator core within Lobby 005, bounded horizontally by grid lines D and E. Vertically, its left wall aligns with grid line 2, but it does not span the full bay to grid 3 (restrooms are located between the shaft and grid line 3). While Section 1 (A4/A510) correctly matches the D and E boundaries, Section 2 (A5/A510) incorrectly depicts the shaft a...

Why it matters: This is a coordination failure between the floor plans and the elevator sections. The incorrect grid references on Section 2 (A5/A510) imply the elevator occupies the full width of the bay between grids 2 and 3 and is located near grid C. If built according to the Section 2 grid labels, it would ...

Suggested next step: Please clarify the correct grid references for the elevator shaft on Section 2 (A5/A510). The plan correctly shows the elevator between grids D and E, adjacent to grid 2 but not extending to grid 3. Section 2 references grids C, 2, and 3, inaccurately implying a full bay width...

RFI draft: Please clarify the correct grid references for the elevator shaft on Section 2 (A5/A510). The plan correctly shows the elevator between grids D and E, adjacent to grid 2 but not extending to grid 3. Section 2 references grids C, 2, and 3, inaccura...

Summary: The Level 00 Annotation and Dimension Plans (A110) depict VESTIBULE 001, FIRE RISER 002, and LOBBY 005 as adjacent rooms without any stairs or ramps, implying they reside on the same continuous floor elevation. However, the referenced wall sections on A334 (Detail 4 for the Vestibule and Detail 3 for the Fire Riser) locate the slab-on-grade foundation for these exterior rooms at 'VESTIBULE LOW ...

Why it matters: If the vestibule and fire riser rooms are physically located 6 feet below the main Level 00 lobby, the floor plan is missing critical stairs and ramps required for access and life safety egress. If these rooms are intended to be flush with Level 00, the wall sections are incorrectly detailing the...

Suggested next step: Please clarify the intended finished floor elevation for VESTIBULE 001 and FIRE RISER 002. If their floors are at VESTIBULE LOW (2166'-2"), please update the A110 floor plan to include the necessary stairs/ramps connecting them to the main Level 00 Lobby (2172'-2"). If their f...

RFI draft: Please clarify the intended finished floor elevation for VESTIBULE 001 and FIRE RISER 002. If their floors are at VESTIBULE LOW (2166'-2"), please update the A110 floor plan to include the necessary stairs/ramps connecting them to the main Level 0...

Summary: There is a direct contradiction regarding the floor plan layout and cross-referencing between horizontal grids B and C on Level 01. Drawing A500 'STAIR 1 - LEVEL 01 ENLARGED PLAN' locates Stair 1 between Grids B and C, and incorrectly includes an elevation callout '4/A622' within this space. Conversely, drawing A622 'LEVEL 01 - ENLARGED PLAN COPY / PRINT & BREAK ROOM' indicates that the space a...

Why it matters: This grid shift and overlapping programming (Stair 1 vs. Copy/Print/Break Room) across different sheets represents a major architectural coordination failure. If the primary stair layout contradicts the interior casework plan in terms of grid locations, it will lead to severe framing, spatial, an...

Suggested next step: Please clarify the correct layout for Level 01 between Grids B, C, and D. Is Stair 1 located between Grids B and C (per A500), or are the Copy/Print and Break Rooms located there (per A622)? Additionally, please confirm that the casework elevation callout '4/A622' should be re...

RFI draft: Please clarify the correct layout for Level 01 between Grids B, C, and D. Is Stair 1 located between Grids B and C (per A500), or are the Copy/Print and Break Rooms located there (per A622)? Additionally, please confirm that the casework elevation...

Summary: Sheet A501 contains conflicting grid locations for Stair 2, creating a physical impossibility that is confirmed by the grid layout on Sheet A301. The 'STAIR 2 - LEVEL 01 ENLARGED PLAN' locates the stair between horizontal grids D and E. However, the 'STAIR 2 - LEVEL 02 ENLARGED PLAN' and 'STAIR 2 (SECTION 3)' locate the same stair at horizontal grid B. Sheet A301's 'EXT ELEVATION - WEST' confir...

Why it matters: If Stair 2 is constructed at Grids D and E on Level 01 but is designed to arrive at Grid B on Level 02, the stair structure will fail to align vertically. This would cause severe structural and architectural coordination failures, as the foundation, steel framing, stringers, and floor openings wo...

Suggested next step: Clarify the correct grid location for Stair 2. Please confirm if the 'STAIR 2 - LEVEL 01 ENLARGED PLAN' should be located at Grid B instead of Grids D/E, or if the Level 01 plan incorrectly depicts a completely different staircase (such as Stair 0 or 1).

RFI draft: Clarify the correct grid location for Stair 2. Please confirm if the 'STAIR 2 - LEVEL 01 ENLARGED PLAN' should be located at Grid B instead of Grids D/E, or if the Level 01 plan incorrectly depicts a completely different staircase (such as Stair 0...

Summary: Sheet S105 includes a general note delegating the design of lateral brace connections to the fabricator, specifically requiring them to use the un-factored axial forces shown on the elevations. However, the brace forces across the elevations uniformly display a placeholder value of '(0k T or C)'. Furthermore, S301 Detail 6 explicitly requires connection hardware to be sized for 'brace loads', w...

Why it matters: A design force of 0 kips makes it impossible for the fabricator to appropriately size gusset plates, welds, and pinned connections. Since this is the Lateral Force Resisting System (LFRS), designing connections for zero lateral load would compromise the structural integrity of the building. An RF...

Suggested next step: Please provide the actual unfactored (ASD) axial tension and compression design forces for all lateral braces shown on S105, replacing the '0k T or C' placeholder values, so the fabricator can design the connections as instructed by the elevation notes.

RFI draft: Please provide the actual unfactored (ASD) axial tension and compression design forces for all lateral braces shown on S105, replacing the '0k T or C' placeholder values, so the fabricator can design the connections as instructed by the elevation ...

Summary: The SPREAD FOOTING SCHEDULE on S500 lists the F9.0 footing mark twice with conflicting reinforcement requirements. One entry specifies '(9) #7 EA. WAY BOTTOM' while the second entry specifies '(9) #7 EA. WAY TOP & BOTTOM'. The foundation plan (S100) calls out F9.0 footings, creating a direct contradiction regarding which reinforcement scheme should be installed.

Why it matters: Inconsistent reinforcement specifications can lead to incorrect rebar placement, potential structural inadequacy if top reinforcement is omitted where needed, or unnecessary material costs if the heavier top and bottom reinforcement is used where only bottom reinforcement is required.

Suggested next step: Please clarify which reinforcement requirement applies to the F9.0 footings called out on S100. Should they have top and bottom reinforcement, or bottom reinforcement only?

RFI draft: Please clarify which reinforcement requirement applies to the F9.0 footings called out on S100. Should they have top and bottom reinforcement, or bottom reinforcement only?

Summary: A drawing note directs the fabricator to design the lateral brace connections based on the "UNFACTORED (ASD) AXIAL FORCES SHOWN IN THE ELEVATIONS." However, the bracing members in the elevations are labeled with placeholder forces of "0k T or C" (zero kips Tension or Compression). IBC Section 1603.1 requires that design loads pertinent to the structural design be indicated on the construction d...

Why it matters: Providing 0 kips as the design load for lateral force-resisting elements fails to provide the fabricator with the necessary information to safely design the structural connections. This omission will delay the shop drawing phase and poses a critical risk of structural failure if connections are n...

Suggested next step: The structural notes indicate that the fabricator is to design lateral brace connections for the axial forces shown in the elevations, but all diagonal braces are tagged with "(0k T or C)". Please provide the actual unfactored (ASD) axial design forces for all lateral bracing ...

RFI draft: The structural notes indicate that the fabricator is to design lateral brace connections for the axial forces shown in the elevations, but all diagonal braces are tagged with "(0k T or C)". Please provide the actual unfactored (ASD) axial design f...

Summary: Detail 10 specifies to attach a deck support to an "EXISTING ROOF JOIST" and explicitly instructs to "COPE SIMILAR @" a wide flange beam. Coping or cutting the bearing ends or chords of a manufactured open web steel joist destroys its structural capacity.

Why it matters: Steel joists are proprietary engineered components that cannot be field-coped without rendering them structurally deficient and liable to fail. Instructing the contractor to cope an existing joist as they would a wide flange beam is a critical structural detailing mistake that could lead to local...

Suggested next step: Revise the detail to provide a connection to the existing roof joist that does not require coping, or verify if the existing member is actually a wide flange beam rather than an open web joist.

RFI draft: Revise the detail to provide a connection to the existing roof joist that does not require coping, or verify if the existing member is actually a wide flange beam rather than an open web joist.

Summary: Structural drawing S105 ('LATERAL BRACE ELEVATION - C') specifies '1"Ø ROD' cross-bracing between the Low Roof and High Roof across Grids 4-8, and 'HSS5X5X3/8' inverted V-bracing between Grids 4-5 on the North perimeter. Architectural drawings A300 and A301 ('EXT ELEVATION - NORTH') show a continuous band of unobstructed clerestory windows at the roof level and large glazed panels between Grids...

Why it matters: The diagonal rod bracing will cross the clerestory windows, and the HSS bracing will intersect the large curtain wall sections. This uncoordinated structural framing will compromise the architectural design, daylighting intent, and potentially conflict with window mullion alignments.

Suggested next step: Please advise how to coordinate the 1"Ø rod cross-bracing and HSS5x5 inverted V-bracing on the North elevation with the continuous clerestory windows and glazed panels shown on the architectural elevations. Should the mullions be aligned with the rod bracing nodes, or does the...

RFI draft: Please advise how to coordinate the 1"Ø rod cross-bracing and HSS5x5 inverted V-bracing on the North elevation with the continuous clerestory windows and glazed panels shown on the architectural elevations. Should the mullions be aligned with the ...

Summary: The structural floor framing plans locate the 'OPEN TO ELEVATOR' shaft in the western structural bay between vertical grids 2 and 3. Conversely, the architectural slab and dimension plans locate the elevator shaft (marked 'FRONT') in the central bay, adjacent to the 'IDF 121' and 'RECORDS & ARCHIVES 122' rooms.

Why it matters: This discrepancy represents a major spatial and structural miscoordination. The primary steel framing, foundation pits, and slab openings are currently designed in a completely different location than the architectural layout requires, which will halt construction of the core and structural slabs...

Suggested next step: Please clarify the intended location for the elevator core. Update the structural framing plans to support the central architectural shaft location, or revise the architectural plans to place the elevator in the western core as framed on the structural plans.

RFI draft: Please clarify the intended location for the elevator core. Update the structural framing plans to support the central architectural shaft location, or revise the architectural plans to place the elevator in the western core as framed on the struc...

Summary: Framing Elevation - A on sheet S107 (Page 9) calls out detail '16 S300' for the cantilevered beam connection at grid C. However, detail 16/S300 (Page 12) depicts a 'CANTILEVER BEAM w/ CONT. COLUMN - B' where the column is continuous and extends both above and below the horizontal beam, including a 3/4" top base plate for the upper column segment. Framing Elevation - A shows the beam at the top ...

Why it matters: Fabricating the steel using the referenced detail 16/S300 would result in unnecessary top base plates and potential connection misalignments, as it assumes an upper column extending upward. A detail without an upper column extension (such as detail 5/S300 'CANTILEVER BEAM') appears to be the corr...

Suggested next step: Please confirm the correct detail for the cantilevered beam connection at grid C on Framing Elevation - A. Should the callout '16 S300' be revised to reference detail '5 S300' or another detail that does not include an upper continuous column?

RFI draft: Please confirm the correct detail for the cantilevered beam connection at grid C on Framing Elevation - A. Should the callout '16 S300' be revised to reference detail '5 S300' or another detail that does not include an upper continuous column?

Summary: The framing elevations on sheet S107 specify 4-inch long headed studs (1/2"Øx 4") for the typical screenwall embed plates. However, the referenced detailed sections on sheet S304 consistently require 5-inch long headed studs (1/2"x 5").

Why it matters: The length of headed studs dictates the embedment depth into the concrete, which directly impacts the structural pull-out and shear capacity of the screenwall connections. Using undersized studs could compromise the structural integrity of the assembly, while a discrepancy in procurement can caus...

Suggested next step: Please clarify the required length for the headed studs on the screenwall embed plates. Should they be 4 inches long as noted on the S107 elevations, or 5 inches long as detailed in the S304 sections?

RFI draft: Please clarify the required length for the headed studs on the screenwall embed plates. Should they be 4 inches long as noted on the S107 elevations, or 5 inches long as detailed in the S304 sections?