Lesson 8.4
Coordination & Checking
A set of drawings is only as good as its agreement. When the plan says one thing and the section another, the building gets built wrong — and someone pays. Coordination and checking are the quiet, essential discipline that makes a set trustworthy.
Start hereA window is 1200 mm wide in the plan, 1000 in the elevation, and missing from the schedule. Which is right? The builder has to guess — and a guess on site is a mistake waiting to happen.
Catching that disagreement before the drawings leave your desk is the whole job of checking.
01 — Spot the disagreement
The drawings must agree
From Module 4.5 you know a set must be internally consistent: the same feature must read the same way in every drawing that shows it. Coordination is the active work of keeping it so. Below, the plan and elevation of one wall start out disagreeing — find and fix the error.
Until both drawings show the same width, the set is wrong. Coordination is making every view agree — for every feature, across the whole set.
The elevation is fixed at 1200. Toggle the plan width until both drawings agree — that is coordination.
02 — How professionals check
Systematic, not hopeful
Checking isn't glancing and hoping — it's systematic. Professionals use repeatable habits: cross-reference every feature across the drawings that show it; check dimensions add up (the detail string should equal the overall, from 5.1); verify every tag on a plan has a matching entry in its schedule; confirm every reference flag points to a sheet that exists; and review against the code one last time. Many offices use a printed checklist and a "redline" pass — marking up a printout in red, then correcting — precisely so checking doesn't depend on memory or mood.
| Check | Catches |
|---|---|
| Cross-reference views | Plan/section/elevation disagreements |
| Dimensions add up | Arithmetic errors, gaps |
| Tags vs schedules | Missing or mismatched doors/windows |
| Reference flags resolve | Callouts to sheets that don't exist |
| Code review | Non-compliant dimensions |
03 — The culture of care
Someone will build exactly what you drew
Behind all the techniques is a single attitude: care. A builder will build, literally, what your drawings say — including the mistakes. A wrong dimension becomes a wrong wall; a forgotten code clearance becomes a failed inspection or, worse, an unsafe building. Holding that reality in mind — that real people will act on your lines, and that errors cost money, time and sometimes safety — is what turns drawing from an academic exercise into a professional responsibility. Check your work as if someone's home depends on it, because it does.
On a real project, dozens of people across multiple disciplines — architects, structural and services engineers, contractors — all draw the same building, and their drawings must align: the structural beam can't clash with the architectural ceiling, the duct can't run where a window is. Coordination is the enormous, unglamorous work of resolving these clashes before they reach site, where fixing them costs ten or a hundred times more. Modern practice increasingly uses 3D building-information models (BIM) precisely to catch clashes automatically — but the discipline is the same one you're learning at the scale of a single set: make everything agree. An uncoordinated set isn't just untidy; it's dangerous and expensive. This is why checking, though invisible in the finished building, is one of the most valued skills a drafter can have. The drawings that never caused a problem on site are the mark of a true professional.
15 minutes
- Use the demo: fix the window so plan and elevation agree. Note how the readout changes from error to coordinated.
- Take a small set you've drawn (or sketch one). Do a redline pass: print it, mark every disagreement in red, then correct.
- Run the five checks from the table on it. How many issues did you catch?
- Pick one dimension string and confirm the parts add up to the overall.
Key terms — added to the Drawing Atlas
- Coordination
- The active work of keeping every drawing in a set in agreement, resolving clashes before they reach site.
- Internal consistency
- The requirement that the same feature reads the same way in every drawing that shows it (see also Module 4.5).
- Redline
- A checking pass in which errors are marked in red on a printout, then corrected — so checking doesn't rely on memory.
- Clash detection
- Finding where elements from different drawings or disciplines collide (a beam through a duct); increasingly automated with BIM.
- BIM
- Building Information Modelling — a coordinated 3D model from which drawings derive, used to catch clashes automatically.
Check yourself
2 quick questions — pick an answer to see why.
Q1If the plan shows a window 1200 mm wide and the elevation shows 1000 mm, the set is…
Q2Which is a systematic checking habit professionals use?
- A set must be internally consistent — every feature reads the same in every view.
- Check systematically: cross-reference, dimensions add up, tags match schedules, flags resolve, code review.
- Coordination resolves clashes before site, where fixes cost far more; BIM automates clash-checking.
- Behind it all is care: someone builds exactly what you drew, mistakes included.
You now know every stage — sketch, develop, set, coordinate. Time to walk the whole journey end to end, from a napkin idea to a finished, checked sheet, in one piece.