What Universities Don't Teach: The Art of Structural Engineering Judgment

In the world of structural engineering, everyone learns the code. Everyone models the structure. Everyone checks PMM ratios, rebar percentages, and modal participation factors. But what truly separates the experienced from the novice isn’t technical knowledge alone—it’s judgment.

1. Code is the Floor, Not the Ceiling

Codes provide the minimum standards. They define what’s legal, not what’s optimal. In practice, relying solely on minimum code values is a recipe for brittle performance, rebar congestion, and long-term serviceability problems.

"PMM = 1.0 means it just survived on paper. PMM = 0.7 means it breathes in an earthquake."

Parameter	Code Minimum	Best Practice (Tall Buildings)
Shear wall thickness	200 mm	500–600 mm at base
Vertical rebar ratio	0.25%	0.6% – 1.0% in web, >1.5% in boundary
PMM ratio	≤ 1.0	≤ 0.70 for robustness

2. Real Structures Aren't Made of Math

You can't place DB20@75 mm because the spreadsheet said so. Construction tolerances, bar clashes, formwork limits, concrete vibration — all dictate that designs must be buildable, not just "passable."

"If you can't pour it, you can't build it. If you can't build it, it doesn't matter what the software says."

3. Structural Sense Comes from Experience

Judgment is about knowing when something feels wrong:

• A 300 mm wall for 30 stories? It might pass the code, but it won't pass a seismic review.

• No boundary element on a heavily loaded core wall? Not if you want it to survive lateral drift.

• 0.25% vertical rebar in a drift-critical zone? Legal, but not wise.

Experienced engineers have seen failures, reviewed cracked buildings, and argued with contractors. They know the bounds: not just what the code says, but what history whispers.

4. The Role of Reserve

A design that only just passes has no safety margin. Real-world loads vary. Concrete pours are imperfect. Earthquakes don't read the load combinations.

That’s why good engineers add reserve:

• Overdesign thickness for drift and P-Δ

• Add extra steel in critical zones

• Check behavior, not just capacity

5. What to Teach the Next Generation

Encourage young engineers to:

• Question what software tells them

• Think about how the load flows

• Visit sites and touch concrete

• Study failures, not just safe structures

• Understand that passing isn't succeeding

"Codes don’t keep buildings safe. Engineers do."

Final Words

Structural engineering judgment isn’t found in tables or textbooks. It’s forged in responsibility, sharpened by mistakes, and strengthened by understanding. As engineers, we must aim not just to satisfy the code, but to safeguard lives, ensure longevity, and deliver trust.

Let this be the mindset that guides every drawing you stamp and every detail you draft.