Shop drawings are one of those construction terms people hear constantly on site but rarely get a clear explanation of — often confused with the design drawings they’re actually derived from. Here’s shop drawings construction explained properly, along with why the review process matters more than it might look on paper, using Sagheer Avenue G+6, a mixed-use residential and commercial development on a constrained site in Pakistan, where I worked as Civil Site Engineer from 2020 to 2022.
This post pairs with Project Engineer Skills, which references the shop drawing review stage on this same project as a key moment where a drawing conflict was caught early.
A shop drawing is a detailed technical drawing prepared by a contractor, supplier, or fabricator, based on the original design drawings, showing exactly how a specific element will actually be built, fabricated, or installed. Design drawings from the architect or structural engineer establish intent — dimensions, materials, general layout. Shop drawings translate that intent into the practical specifics needed to actually build it: exact reinforcement placement, connection details, fabrication dimensions, and installation sequencing information relevant to that specific element.
The distinction matters because a design drawing can be technically correct and still leave real construction questions unanswered. A structural drawing might show a beam-column connection in principle; the shop drawing for that connection shows the exact bolt pattern, weld details, and tolerances the fabricator needs to actually produce it.
Construction drawings (sometimes called design drawings or working drawings) are prepared by the design team — architect, structural engineer, MEP consultant — and represent the approved design intent. Shop drawings are prepared afterward, usually by the contractor or a specialist fabricator, and represent how that design intent will actually be executed. Construction drawings answer “what is being built.” Shop drawings answer “exactly how, with what dimensions and materials, will this specific piece be produced and installed.”
This is also why shop drawings require formal review and approval before use — they aren’t simply administrative paperwork confirming what was already decided; they’re the point where design intent either translates cleanly into buildable reality, or where a conflict surfaces that needs to be resolved before construction reaches that point.
On Sagheer Avenue G+6, the shop drawing review process followed a consistent structure, floor by floor:
Submission — the contractor or fabricator submits the shop drawing, referencing the relevant design drawing and specification section it’s based on.
Technical review — checking the shop drawing against the approved design drawings and specifications, and, critically, against shop drawings from other disciplines working in the same physical space.
Comments or approval — the drawing is either approved, approved with comments requiring minor revision, or returned for resubmission if it doesn’t meet the design intent or conflicts with other disciplines.
Resubmission if needed — a revised drawing goes through the same review before it’s cleared for construction use.
This cycle happening well ahead of actual construction, rather than in parallel with it, is what makes the review process valuable rather than a bottleneck. On a constrained site with limited room to rework completed work, catching an issue during this cycle is dramatically cheaper than catching it once concrete has been poured or steel has been fabricated to the wrong dimension.
The stakes of shop drawing review scale with how much room a site has to absorb a mistake. On an open site with generous laydown space, a shop drawing issue caught late might mean reordering a fabricated element with manageable delay. On Sagheer Avenue’s constrained footprint, there was no equivalent slack — limited staging space meant materials arrived closer to when they were needed, which meant a drawing conflict discovered after fabrication had already started could hold up the floor above it with almost no room to work around the problem. This is what made the shop drawing review stage on this project less of a formality and more of a genuine risk-control point.
During the shop drawing review stage on Sagheer Avenue, cross-checking the structural and electrical shop drawings for one of the upper floors surfaced a conflict between a beam location and a planned electrical conduit run — the kind of issue that’s a straightforward drawing revision when caught at this stage, and a genuinely disruptive on-site problem if it isn’t. Resolving it on paper, before either discipline’s work reached that floor, meant no rework, no schedule impact, and no argument later about which discipline should have caught it first.
Who is responsible for preparing shop drawings?
Typically the contractor, subcontractor, or a specialist fabricator responsible for that specific element — not the original design team, though the design team’s drawings and specifications are the basis the shop drawing must comply with.
How long does shop drawing review typically take?
It varies by project and consultant workload, but the review cycle should be planned into the schedule well ahead of when the element is actually needed on site — treating it as a late-stage formality is a common cause of avoidable delay.
Are shop drawings the same as as-built drawings?
No. Shop drawings are prepared and approved before construction of an element, showing how it will be built. As-built drawings are prepared after construction, recording how it was actually built, including any changes made along the way.
Aown Muhammad is a Project Engineer based in Dammam, Saudi Arabia, registered with the Saudi Council of Engineers (SCE) and the Pakistan Engineering Council (PEC), with 7+ years of experience across residential, commercial, and industrial construction projects in Pakistan and Saudi Arabia. View full portfolio and projects →
