What are alteration levels in construction and how do they relate to delegate engineers?

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(2020 Florida Existing Building Code Section 503) (adopted by use of IBC 2018 with amendments, definitions apply nationwide)

Alteration – Level 1 (FBC Existing Buildings Section 602)

  • Removal and replacement, or covering of existing materials, equipment, fixtures using new materials that serve the same purpose.
  • Alteration –Level 1 does not include reconfiguration of space.

Commentary:  Typically the component (delegate) engineer (such as Engineering Express® who are Building Component Design Engineers) serves as the only engineers for this level alteration and do not need to provide host reactions for others or require shop drawing approval.  Since there is typically no architect or engineer above the component engineer, the component engineer produces work either at the master plan (non-site specific) level or addresses a site specific condition with the assistance of the permitting contractor to develop a code compliant solution.


Alteration – Level 2 (Section 603):

Reconfiguration of spaces, the addition or elimination of any door or window, the reconfiguration or extension of any system, or the installation of additional system.

  • Reconfiguration of spaces (i.e. removal and addition of walls that could alter paths of egress.
  • The addition or elimination of any door or window.
  • Reconfiguration or extension of any system or   installation of new equipment such as HVAC,   electrical, plumbing systems,..etc.
  • Requirements for improvements or upgrade outside the scope of work exist in this category.
  • Full compliance with the Code for new construction is not required.
  • Alteration-Level 2 apply where the work area is less than 50% of the aggregate area of the building.

Commentary:   Typically there is an architect and/or engineer of record (AOR/EOR) on level 2 alterations that receives the delegate engineer’s information for approval and incorporation in their design.  Delegate engineers do not have final decisions on design work and are subject to AOR/EOR review and approval.  The contractor typically facilitates coordination between trades, but at times the delegate engineers work directly with the AOR/EOR for approval.  Notes and disclaimers exist on the delegate engineer’s plans to ensure compliance and limited liability that they are serving as delegate engineers (Engineering Express typically is the delegate engineer).  In cases where there is no AOR/EOR, the commentary from level 1 applies.


Alterations-Level 3 (Section 604):

  • Level 3 Alteration is level 2 alterations where the work area exceeds 50% of the aggregate area of the building (total floors area).
  • Work area is defined as that portion or portions of a building consisting of all reconfigured spaces, as indicated in the construction documents.
  • The work area excludes portions of the building in which work not initially intended by the owner is specifically required by the code.
  • Triggers in this classification are work that potentially affects the building’s fire protections systems, vertical openings, means of egress, accessibility and structural system.

Commentary: The notes from level 2 commentary apply with the exception that there would nearly always be an AOR/EOR at this alteration level.  Building Component Engineers such as Engineering Express would   not engage fully in a project of this alteration level and serve exclusively as the delegate engineer.

Last Update: March 31, 2021  

March 23, 2018  Codes & Standards  
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