What are shop drawings?

Why Shop Drawings Are the Key to a Smooth Construction Process

Every project starts with a design — a vision of what the building will look like and how it’s supposed to work.
But turning that vision into something that actually fits and functions in the field? That’s where things often go sideways.

A lot of confusion (and frustration) on construction sites comes from misunderstanding the difference between contract drawings, coordination drawings, and shop drawings. Each one serves a purpose, but only one of them truly shows how your project gets built in the real world.

Let’s walk through what they are — and why shop drawings are where the real work happens.

What Are Contract Drawings?

Contract drawings — sometimes called design drawings — are the plans the architect or engineer provides.
They show the intent of the design: how systems should generally run, what should connect where, and the overall layout of the building.

But they don’t show how those systems will actually fit together in the field. Most of the time, they’re single-line diagrams — great for concept, not so great for fabrication. Ducts, pipes, and conduits are often drawn as simple lines, without accounting for real-world dimensions, slopes, or clearances.

In short:
Contract drawings tell you what to build — not how to build it.

What Are Coordination Drawings?

Coordination drawings take the design to the next level.
These are usually developed by the mechanical, electrical, plumbing, and fire protection (MEP) contractors to make sure every trade can install their work without conflicts.

At this stage, we’re making sure everything actually fits — that your ductwork clears the beams, your drainpipes slope properly, and your conduits don’t block access panels.
This is often done using 3D modeling (BIM), but the goal is the same even in 2D: find and fix problems before they hit the field.

Why coordination drawings matter:

• They uncover clashes between trades early.

• RFIs can be handled before crews mobilize.

• Prefabrication becomes smoother and faster.

• Everyone installs with confidence instead of guesswork.

When coordination is skipped (often under “Value Engineering” to cut costs), you’re left coordinating in the field — which really means paying for rework later.

What Are Shop Drawings?

Once everything is coordinated, each trade produces shop drawings — the final, fabrication-ready version of the plan.

This is where all the thinking and coordination turn into exact measurements your shop and installers can trust.
Shop drawings include:

• Dimensions and elevations down to the inch

• Hanger and support locations

• Equipment connections and clearances

• Sleeve and penetration locations

• Consistency between plans, risers, and details

These drawings are what the fabrication shop and field crews actually use.
They’re the difference between hoping it fits and knowing it fits.

Why Contract Drawings Alone Don’t Cut It

If coordination or shop drawings are removed from the scope — which happens too often under Value Engineering — the trades are left working from diagrammatic contract drawings. That’s where problems start.

Ceilings end up too tight.
Pipes can’t slope correctly.
Ducts clash with lights or trusses.

And suddenly the contractor is redesigning on the fly, taking on risk that was never part of their scope.
It’s a quick way to lose time, money, and patience.

Why Shop Drawings Matter

1. They Catch Problems Early

Shop drawings turn design intent into reality on paper first — spotting missing duct sizes, bad slopes, or conflicts before anyone cuts material.

2. They Save Time and Money

Fixing a clash on paper takes minutes. Fixing it in the field can cost days.
Accurate drawings mean less rework, fewer delays, and more predictable budgets.

3. They Improve Accuracy

When your plan, riser, and sections all align perfectly, your systems go in cleanly and function the way they should.

4. They Protect You

Once approved, shop drawings serve as your record that the engineer reviewed and accepted the design. If issues come up later, you’ve got documentation to back up your work.

5. They Leave a Good Impression

As-built shop drawings are usually the last thing the owner sees from you. Delivering clean, accurate drawings at closeout makes you look professional — and helps you win the next project.

Real Lessons From the Field

We’ve all seen what happens when drawings come too late: ceilings get dropped, soffits cut across windows, or whole rooms get redesigned mid-build.
Every one of those issues could’ve been caught with proper coordination and shop drawings done early.

There’s an old saying — measure twice, cut once.
In our world, it’s coordinate twice, build once.

Conclusion

Contract drawings show the idea. Shop drawings make it buildable.
They’re the bridge between the engineer’s intent and the installer’s reality.

When you invest in detailed coordination and shop drawings early on, you save yourself time, stress, and expensive surprises down the road.

At ShopDrawings.com, that’s exactly what we focus on — clear, accurate, buildable drawings that make your install go smoother from day one.

Plan it right. Draw it right. Build it right.