A common conversation in architectural circles involves using a delegated design approach to nonstructural interior partitions and ceilings. What is delegated design? Who is responsible for the approach? Is it appropriate for interior nonstructural cold-formed steel (CFS) applications?
Let’s answer the last question first. Use a delegated design approach with interior CFS framing? Probably not.
The Steel Framing Industry Association recommends that designers should follow a performance-based specification for interior CFS framing applications. Why is that?
Delegated Design and CFS
Traditionally, the delegated design process was reserved for structural applications of CFS framing. And here, delegated design is well established. It is described in both the national guidelines for structural engineers published by the Coalition of American Structural Engineers (CASE) and the AISI S202-20, Code of Standard Practice for Cold-Formed Steel Structural Framing.
What is Delegated Design?
In one definition, the design professional establishes the performance requirements for an element of a building, and a contractor assumes the responsibility of designing that element. Delegated design is based on the underlying contract language governing the project.
- The AIA Contract Document C404™-2021, “Standard Form of Agreement Between Contractor and Consultant for Delegated Design Services” has the contract language for this type of delegated design process.
Not Common in Interior CFS Applications
The architect would provide the performance requirements for various nonstructural elements. These would include:
- Fire resistive requirements
- Sound performance requirements, such as STC ratings
- Structural requirement, such as height of the wall and fixture loading
- Moisture requirements, such as vapor and temperature drives
- Sustainability requirements
The contractor would be tasked with providing a solution to meet the requirements.
“The use of this design process is not common for interior partitions,” says Robert Grupe, SFIA general manager, architectural services, “but many architects are re-thinking how they approach design solutions.”
“In my experience, ceilings have been increasing in complexity,” says Patrick Ford, SFIA technical director. “This and the inherent danger of an event failure has given rise to most interior delegated design requirements.”
How is Delegated Design Administered?
The delegated design process is administered through the construction drawings, such as the architectural specifications and partition schedules.
The architectural specifications and the drawings should be tightly coordinated so there is no confusion as to the intent of, and the adherence to, specified performance requirements.
In the architectural specification, the delegated design definition starts with Division 01 of MasterFormat® (2020 ed.), which covers submittal procedures, shop drawings, product data and samples (if required). Section 01 35 73 of Division 01 is entitled, “Delegated Design Procedures.” Then, more information should be conveyed in the appropriate specification section:
- 054000 Cold-Formed Metal Framing
- 092116 Gypsum Board Assemblies
- 092216 Nonstructural Metal Framing
- 095700 Acoustical Ceilings
In the end, delegated design must be described in the contract documents. The language found in AIA Contract Document C404-2021 can be used. It’s a standard form agreement where a contractor can hire a consultant to perform delegated design services on a project.
A Better Option for Nonstructural CFS Applications
What drives delegated design is the increased level of complexity of interior nonstructural systems and increased oversight through the ever-expanding role of evolving model building codes and regulatory standards. And it is especially evident in the healthcare and education segments.
“The design of cold-formed steel framing systems has many intricacies,” says Grupe. “There are issues involving composite design, the effect of sound performance by steel thickness and framing spacing, proprietary versus generic design, and they all give rise to the thought of just letting the contractor solve the design problem with their preferred vendor partner.”
CFS Performance-Based Design
An alternative to delegated design in interior nonstructural applications is to closely follow a performance-based option for nonstructural CFS framing.
In this case the professional designer dictates the desired level of performance through the architectural specifications, which are then clearly communicated in the construction documents, primarily through the partition schedule.
- Each wall type would be delineated with key information, such as framing type, spacing, wall height, fire resistance and acoustical attenuation requirements
- Contractors call out their proposed solution in their bids through action submittals
“Action submittals require the architect’s approval which closes the communication loop,” Grupe says.
Thus, a performance-based option allows the design profession to maintain the right and responsibility for final approval thus assuring that all design parameters are met.
Again, the Steel Framing Industry Association recommends the performance-based specification for nonstructural CFS framing applications.
Delegated Design FAQs
What is Delegated Design?
Delegated Design describes a form of design collaboration where the contractor assumes responsibility for an element or portion of a project’s design. … C404-2021 is a flexible agreement that allows the parties to define the portion of the design that will be performed by the consultant. (Source: AIA Contract Document C404-202)
Who is Responsible?
The building designer is responsible for the overall design of the building as required by the applicable building code. The building designer or the owner is permitted to solicit designs, plans, building design models, specifications and data for the CFS structural framing or CFS component assemblies, or steel deck, from the CFS component manufacturer, installer, specialty designer, or steel deck supplier. However, the responsibility for specifying the requirements of the design, including the applicable building codes and standards, remains with the building designer. (Source: AISI S202, A5.1)
Who is the Designer?
Building Designer. Owner of the building or the person that contracts with the owner for the design of the framing structural system or who is responsible for the preparation of the construction documents. When mandated by the legal requirements, the building designer shall be a registered design Professional. (Source: AISI S202)
Specialty Designer. The registered design professional individual or organization having responsibility for the design of the specialty items. This responsibility shall be in accordance with the state’s, province’s or territory’s statutes and regulations governing the professional registration and certification of architects or engineers. Also referred to as CFS component designer, specialty engineer, delegated engineer, design engineer, registered engineer, and engineer, but hereinafter shall be referred to as Specialty Designer. The requirement for a Specialty Designer is typically called out in the specification or general notes. The Specialty Designer is typically not the building designer. (Source: AISI S202)
What Must Be Documented?
Specifications. Written instructions, which, with the plans or building design model, define the materials, standards, design of the products, and workmanship expected on a construction project. (Source: AISI S202)
Plans. Also referred to as construction drawings. Drawings prepared by the building designer for the owner of the project. These drawings include, but are not limited to floor plans, framing plans, elevations, sections, details and schedules as necessary to define the desired construction. (Source: AISI S202)
Construction Documents. Written, graphic and pictorial documents prepared or assembled for describing the design (including the framing structural system), location and physical characteristics of the elements of a building necessary to obtain a building permit and construct a building. Construction documents include the specifications and plans, or where the parties have agreed in the contract to provide 3D digital model(s), the building design model. A combination of drawings and 3D digital models also may be provided. (Source: AISI S202)
Are Delegated Design and Design-Build the Same?
No. Delegated design is a design collaboration. Design-build is a project delivery method where the owner signs one contract with a single organization that will both design and construct a given building or structure.
Are Delegated Design and Design Assist the Same?
No. In design assist, the contractor provides technical information to the architect in crafting the project design. In this scenario, there are individual contracts between the owner and the architect, and then again between the owner and the contractor. The architect is liable for the overall design, whereas the contractor is liable only for the information provided.
Additional Resources
- SFIA Releases Updated Technical Guide with the Most Up-to-Date CFS Load and Span Tables in the Industry
- Steel—Doing It Right® #3: Engineering Considerations
- How to Navigate Change Orders with Cold-Formed Steel