Outsourcing structural steel detailing works best when you hand over a defined package: agreed inputs, a deliverables list, a stated responsibility split, a review cycle and a handover format. Your team keeps design authority and approval, and the subcontractor supplies production capacity. Most outsourcing problems trace back to undefined scope, not to distance or time zones.
When does outsourcing steel detailing make sense?
Outsourcing tends to work well when:
- the in-house team is at peak load and the backlog is delaying fabrication;
- packages are well bounded, such as a pipe rack, a set of equipment platforms, or a skid-steel package;
- the design is stable enough to detail, or can be split into frozen areas;
- you can name a single technical point of contact on your side.
It is harder when:
- the design is still moving daily and decisions are made informally on site;
- the detailer is expected to resolve design questions without access to the engineer;
- nobody owns the review of returned drawings.
Define the package before you approach suppliers
Before requesting quotations, write a one-page package definition:
| Item | Example entry |
|---|---|
| Scope boundary | Pipe rack PR-01 to PR-04, including secondary steel for pipe supports; excludes stairs |
| Inputs available | IFC structural drawings rev C, piping support loads rev B, vendor data pending for two items |
| Deliverables | Tekla model, assembly and single-part drawings, erection GA, bolt list, MTO |
| Responsibility | Connections per project standard details; non-standard connections designed by EPC structural team |
| Standards | Project specification; drawing standard per client procedure |
| Software and formats | Tekla Structures (version to be agreed); deliver native, IFC, PDF, DWG, NC/DSTV |
| Review | Client comments within an agreed number of working days, one consolidated comment set per issue |
| Milestones | Anchor plans first, then rack by rack |
This definition becomes the basis of your RFQ (see our guide on writing an RFQ for a detailing package) and later the statement of work.
How do you evaluate a detailing subcontractor?
Price matters, but it is a poor predictor of fabrication outcomes on its own. A simple weighted scorecard helps:
| Criterion | What to ask for | Evidence to look for |
|---|---|---|
| Relevant experience | Examples of similar structure types (pipe racks, platforms, modules) | Sanitised sample drawings; clear distinction between company work and individuals' prior employment |
| Scope understanding | Their questions after reading your package | Specific RFIs and assumptions, not just a price |
| Responsibility clarity | How they treat connection design and approvals | Written boundaries, no blanket "we design everything" |
| Checking process | How drawings are checked before issue | Named checking step, checklists, separation of modeller and checker |
| Revision control | How revisions and superseded sheets are handled | Drawing register, revision clouds, transmittals |
| Software and formats | Version compatibility and exchange formats | Confirmation of the version and a test exchange |
| Communication | Point of contact, working hours overlap, query turnaround | Named lead; agreed query log |
| Data security | How your files are stored and shared | NDA willingness; controlled file transfer |
Be cautious about claims that cannot be checked: "error-free", "100% accuracy", or savings percentages given without a stated basis. For a sense of how we handle checking, see our quality and delivery approach.
Managing the work
- 1Kickoff. Walk through the inputs, the responsibility split, priorities and the drawing standard. Agree the query log format.
- 2Queries. Batch RFIs daily or weekly. Answer in writing, and record answers in the log so they are not lost in email or chat.
- 3Staged issues. Ask for a sample assembly and erection drawing early, so you can correct conventions before the whole package is dressed.
- 4Reviews. Consolidate comments from engineering, fabrication and QA into a single return per issue. Conflicting comments from different reviewers are a common cause of churn.
- 5Revisions. Require revision letters, clouds and an updated register with every re-issue.
Data security and confidentiality
Energy project drawings are often confidential. Agree an NDA where needed, define which platforms are used for file transfer, limit access to named personnel, and agree what happens to files at project close. PetroHill can work under a client NDA and agreed transfer arrangements. Raise this when you contact us.
What should you receive at handover?
At completion, expect native model files (if contracted), PDFs, DWGs, reports, NC data, a final drawing register and a list of open items or assumptions. Confirm model ownership and licence compatibility in advance.
Frequently asked questions
Does outsourcing transfer design responsibility?
No, unless explicitly contracted to an appropriately qualified party. The usual arrangement is that the client's engineering team retains design and approval authority.
How do we handle time-zone differences?
Agree a daily overlap window and a written query log. A clear package definition matters more than real-time availability.
Can we start with a small trial package?
Yes. A single rack bay or platform is a practical way to test conventions, communication and quality before awarding more.
Next step
PetroHill supports EPC contractors, consultancies and fabricators with defined CAD, modelling and detailing packages while your team retains engineering authority. See how outsourcing works or discuss your engineering package.
Related services
References
Technical sources consulted. Standards are paid documents; confirm clauses against the licensed edition named in your project specification.
- Structural Steel Detailing Practices—Good and Bad · AISC EJ (opens in a new tab)
