Last updated: July 24, 2026
In a precast project the engineering splits into two roles. The structural engineer of record (SER), the project’s design engineer, specifies the applicable code, the design loads, and the performance criteria in the contract documents. The precaster’s specialty structural engineer (SSE), working for the precast supplier, then designs the precast units and their connections to those criteria and stamps the precast shop drawings, a “delegated design.” CSA A23.4 requires precast shop drawings in addition to the design requirements of CSA A23.3, and in Alberta that engineering must be authenticated by a P.Eng. under an APEGA Permit to Practice.
The principle that answers “who owns the variance” is this: the engineer of record can delegate design tasks but cannot delegate design responsibility. The SER’s seal puts them in responsible charge of the whole project, including delegated items, while the precaster’s engineer owns the connection and unit design they stamped. So a connection or fit variance is owned by whoever’s design it was. If the SSE designed the connection, the precaster’s engineer owns it; if the SER’s documents created the conflict, it traces back up the chain. The cleanest projects make that boundary explicit in the spec.
This is the specifier’s and general contractor’s liability question, and it has a real answer. (For the plant’s quality certificate, a separate gate, see “A Specifier’s Guide to CPCQA Categories”; for the spec clause that names the engineering authority, see “Drop-In CSA A23.4 Spec Language for Calgary Precast”.) The authoritative weight below sits on the institutional sources, AISC, ASCE, CSI, CSA A23.4, and APEGA, with practitioner consensus used only to corroborate.
Two roles, two owners
Precast engineering is not one engineer’s job. It is two, with a clean division of labour.
The framework is the standard delegated-design model. As the institutional guidance describes it, the “design and detailing of connections of the units to the structure are performed by a Specialty Structural Engineer (SSE) either working for or contracted with the precast concrete supplier. If the SSE is… responsible for the final precast concrete design, the applicable code, design loads, and performance criteria must be specified by the structural engineer of record (SER) in the construction documents.”
(Sources: AISC, “Delegated Design and the Engineer of Record,” https://learning.aisc.org/local/catalog/view/product.php?productid=1797 ; CSI, “Shop Drawings and Submittals — Delegated Design,” https://www.csiresources.org/blogs/kevin-obeirne-pe-fcsi-ccs-ccca-cdt1/2021/05/11/shop-drawings-and-submittalsdelegated-design-submi . The AISC material is steel-focused, but the delegated-design framework is identical for precast.)
So the two roles are:
- The structural engineer of record (SER). The project’s design engineer. Sets the code, the loads, the criteria, in the contract documents. Owns the overall structure.
- The precaster’s specialty structural engineer (SSE). Works for the precast supplier. Designs the precast units and the connections to the SER’s criteria, and stamps the precast shop drawings.
Each owns what they design. That is the foundation for everything that follows.
The principle that answers the title
Here is the line that decides who owns a variance, stated by the institutional source plainly:
“The structural engineer of record can delegate design tasks, but cannot delegate design responsibility. The EOR takes responsibility for the entire project which includes delegated design items, and the EOR’s seal… implies that they are in responsible charge for all aspects of the project, delegated or not.”
(Source: ASCE, “Engineering issues associated with delegated design,” https://www.asce.org/publications-and-news/civil-engineering-source/article/2025/09/12/engineering-issues-associated-with-delegated-design ; CSI, URL above.)
Read it carefully, because it has two halves that people tend to collapse into one. Tasks are delegable. The SER does not design the precast connections; the SSE does. But responsibility is not delegable in the same way. The SER stays in responsible charge of the whole project, including the delegated items, by virtue of their seal.
That is not a contradiction; it is two different things. The SSE owns the specific design they performed and sealed, the units and connections. The SER owns the project-level responsibility that the whole thing, including the delegated pieces, conforms to the design intent and the code. Both statements are true at once, and holding them together is the entire skill of answering “who owns the variance.”
Where the precaster’s engineer’s ownership lives
The SSE’s responsibility has a concrete marker: the stamp on the precast design. Practitioner consensus is that “all precast designs should be stamped and sealed by the precast supplier’s engineer,” and that “the engineer of the precasting plant shall submit signed and sealed calculations and drawings when delegated responsibility for design.”
(Source: Eng-Tips precast drawing-liability discussion, https://www.eng-tips.com/threads/precast-drawing-liability.39012/ . This is a practitioner forum, used here to corroborate the norm; the authoritative weight rests on AISC, ASCE, CSI, CSA A23.4, and APEGA.)
So the precaster’s engineer’s ownership is not abstract. It is wherever that engineer’s seal appears, on the unit designs and the connection designs they performed. If a connection the SSE designed and sealed turns out to be the problem, the ownership of that design is clear.
What CSA A23.4 contributes
The Canadian precast standard ties the framework to the actual deliverables. CSA A23.4 “specifies the requirements, in addition to those specified in CSA A23.3, for precast concrete shop drawings.”
(Source: CSA A23.4-16 via ANSI, https://webstore.ansi.org/standards/csa/csaa232016 ; Omega Calgary Concrete Knowledge Base, CSA A23.4.)
That nests neatly into the two-role split. CSA A23.3 is the structural design standard, the SER’s territory. CSA A23.4 adds the precast shop-drawing requirements on top, and the shop drawings are the SSE’s product. So the Canadian standards themselves draw the same line: the design (A23.3) and the precast shop drawings (A23.4) are governed separately, by the two engineers who own them.
The Alberta layer: APEGA
In Alberta, two authentication facts make the chain local and concrete.
First, the individual stamp. Engineering work in Alberta must be authenticated per APEGA’s Authenticating Professional Work Products standard, current edition effective November 1, 2024, and the P.Eng. who stamps takes professional responsibility under Alberta’s Engineering and Geoscience Professions Act.
(Sources: APEGA, Authenticating Professional Work Products, https://www.apega.ca/about-apega/publications/standards-guidelines/authenticating-professional-work-products ; Engineering and Geoscience Professions Act, https://www.canlii.org/en/ab/laws/stat/rsa-2000-c-e-11/latest/rsa-2000-c-e-11.html .)
Second, the firm. A company that practises engineering in Alberta needs an APEGA Permit to Practice, which requires a Responsible Member, a practising APEGA professional in good standing who is accountable for the firm’s engineering.
(Source: APEGA, Responsible Members, https://www.apega.ca/members/responsible-members .)
So in Alberta the precaster’s engineering operates on two levels at once: the individual P.Eng. who authenticates the precast drawings, and the firm’s Permit to Practice with its Responsible Member behind that engineering. Both matter when you are tracing who stands behind a sealed precast design.
How the variance gets caught before it is a fight
The chain is not just for assigning blame after a problem; it is built to catch problems first. The SER does not design the precast connections, but the SER does review the delegated work. As the guidance puts it, “The engineer of record should review the specialty structural engineer’s work… to the degree necessary to support the structural engineer of record’s contractual responsibilities.” (Source: CSI, URL above.)
That review is the handshake that closes the loop. The SSE designs the connection to the SER’s criteria; the SER reviews it for conformance to the criteria they set. A mismatch, a panel that will not fit, a connection that does not suit the framing, is meant to surface in that review, before steel is set and concrete is cast. The system is designed so the variance is found at the drawing stage, where it is cheap to fix.
So, who owns the variance?
Put it all together and the answer to the literal question is clean.
A connection or fit variance is owned by whoever’s design created it. If the SSE designed and sealed the connection, the precaster’s engineer owns that design. If the SER’s contract documents set up the conflict, in the criteria, the geometry, the interface with other trades, it traces back up the chain to the design of record. The SER remains in responsible charge of the project overall; the SSE owns the specific delegated design they stamped. Neither can offload responsibility for the part that was theirs.
The practical takeaway for a specifier or general contractor is the one the cluster keeps returning to: make the boundary explicit in the documents. Specify who designs the connections and to what criteria, require the precaster’s engineering to be authenticated under an APEGA Permit to Practice, and the review loop and the ownership lines are clear from the start. The spec-language guide gives the clause that names that authority.
A note on the integrated-stack question, since it comes up: when cribbing, ready-mix, and precast come from one group, the convenience is real, but it does not blur the engineering responsibility. Delegated design still has a defined owner per the chain above, regardless of how many parties are in the supply stack. Clear responsibility is a feature to insist on, not something a single-vendor arrangement removes.
FAQ
Who is responsible for precast connection design? The precaster’s specialty structural engineer (SSE) designs and stamps the precast units and connections, to the loads and criteria the structural engineer of record (SER) specifies in the contract documents.
Can the engineer of record delegate the precast design? They can delegate the design tasks to the precaster’s engineer, but not the design responsibility. The SER stays in responsible charge of the whole project, including the delegated items, by virtue of their seal.
Who owns it when a precast panel doesn’t fit? Whoever’s design created the variance. If the SSE designed the connection, the precaster’s engineer owns that design; if the SER’s documents created the conflict, it traces up the chain to the design of record.
What does CSA A23.4 say about precast drawings? It sets the requirements for precast concrete shop drawings in addition to the design requirements of CSA A23.3. The design and the precast shop drawings are governed separately, matching the SER and SSE split.
Who stamps precast drawings in Alberta? A P.Eng. authenticating the work under an APEGA Permit to Practice, per APEGA’s Authenticating Professional Work Products standard, with the firm’s Responsible Member accountable for the engineering.
How do you avoid precast engineering disputes? Make the SER and SSE responsibility boundary explicit in the contract documents: specify who designs the connections and to what criteria, and require the precaster’s engineering to be authenticated under an APEGA Permit to Practice.
Does using one company for cribbing, mix, and precast change who’s responsible? No. Delegated design still has a defined owner per the engineering chain, regardless of how many parties are in the supply stack. The responsibility lines stay the same.
Specify Engineering Responsibilities Before Construction Starts
Most precast disputes don’t begin on site—they begin with unclear engineering responsibilities in the contract documents. Whether you’re an engineer, architect, developer, or general contractor, Omega Precast works with your design team to provide CSA A23.4-compliant shop drawings, professionally engineered precast designs, and Alberta-authenticated documentation through an APEGA Permit to Practice.
Talk with Omega Precast early in design to streamline delegated engineering, reduce RFIs, and keep your project moving from specification through installation.