Planning & documentation
Seismic Retrofit Scope for Existing Steel Buildings
Define records, performance objectives, investigation limits, and professional responsibilities for evaluation and seismic retrofit of steel buildings.
Understand the project condition
An existing steel building may be considered for seismic evaluation because of a planned alteration, owner objective, or applicable local requirement. The work can involve records, inspection, analysis, and retrofit design. A generic statement that a building is steel does not establish its seismic performance.
For a US project, begin with the intended use and documents applicable to that site. The building manufacturer, project engineer of record, and contractors may have different scopes. Identify who provides each input and who reviews the interfaces; purchasing a metal building system does not by itself resolve foundations, building services, or occupancy requirements.
References: AISC 342: Evaluation and retrofit of existing structural steel buildings · Assessment and repair of structural steel in existing buildings
Compare decisions before fabrication release
Define the reason for evaluation and the required objective with the qualified project team. Identify applicable standards and local acceptance requirements through the responsible professionals. Review original frames, braces, connections, foundations, and later alterations. State investigation limits clearly; inaccessible conditions may affect the confidence and scope of conclusions.
Compare alternatives on the same project basis. Record dimensions, revisions, and assumptions explicitly, and distinguish a confirmed requirement from a future possibility. When a decision changes reactions, connections, or geometry, request revised documents before authorizing affected work. A sales note or preliminary drawing should not silently become a field instruction.
References: AISC 342: Evaluation and retrofit of existing structural steel buildings · Assessment and repair of structural steel in existing buildings
Coordinate the trade interface
Retrofit design can affect occupied operations, foundations, cladding, and service routes. Coordinate construction-stage stability and access with qualified contractors. Keep owner performance goals distinct from minimum applicable requirements so proposals and completion records address the same intended outcome.
References: AISC 342: Evaluation and retrofit of existing structural steel buildings · Assessment and repair of structural steel in existing buildings
Prepare a reviewable record
This matrix organizes decisions and evidence; it does not provide design capacities or tolerances. Use the project's units and elevation references, and attach complete documents when a screenshot omits applicable notes. Each review should state its scope, unresolved items, and the person responsible for closing them.
| Condition | Required record | Decision supported |
|---|---|---|
| Evaluation purpose | Owner objective and applicable basis | Set a defined review scope |
| Existing system | Records, investigation, and alteration history | Establish evidence and uncertainties |
| Retrofit work | Reviewed design and completion inspections | Demonstrate the agreed modification scope |
References: AISC 342: Evaluation and retrofit of existing structural steel buildings · Assessment and repair of structural steel in existing buildings
Close open items and transfer the information
The final report should identify the evaluated objective, applicable basis, investigation limits, and completed retrofit scope. Preserve unresolved conditions or recommendations instead of reducing the outcome to a universal earthquake-safe claim. Future alterations should review whether they affect the assessed system or objective. Where the project depends on particular occupancy or operational assumptions, include them in the facility record so later owners can interpret the result correctly.
Keep the approved response available to the people performing and inspecting the work. At scope closeout, retain the final revision with its attachments, identified photographs, and resolved items. The following links develop related subjects; manufacturer details and responsible-professional direction remain necessary for the actual project.
- State the evaluation objective before soliciting proposals.
- Have qualified professionals determine investigation and governing criteria.
- Coordinate retrofit work with operations and inspected closeout.
- Purlins vs. Girts: Roof and Wall Secondary Framing Explained
- Steel Connection Documentation Checklist
References: AISC 342: Evaluation and retrofit of existing structural steel buildings · Assessment and repair of structural steel in existing buildings
Common questions
Does replacing one brace establish a complete seismic retrofit?
No. The defined evaluation and retrofit scope must address the relevant system and objective.
Can this guide assign a seismic performance rating?
No. Qualified professionals must evaluate the actual building using applicable criteria.
Sources & further reading
Use the current documentation for the exact product and project. Source links do not imply a partnership or endorsement.
- AISC 342: Evaluation and retrofit of existing structural steel buildings American Institute of Steel Construction
- Assessment and repair of structural steel in existing buildings American Institute of Steel Construction
Prepared with AI assistance. Linked references require current project-specific review. How these guides are prepared.
Prepare a supply inquiry
- Record the project drawing or detail and the specified product, profile, or system.
- List the complete configuration, physical units, quantities, and cuts per piece.
- Request current manufacturer documents; confirm compatibility, price, and availability before ordering.
- Obtain the responsible professional's review for loads, code requirements, or installation.