How engineering work is really done and licensed: project phases, calculation packages, specs and submittals, codes and standards, QA/QC, the FE and PE, and ethics.

Engineering Practice & Licensure

Find out which building code edition your city, county or state has adopted, using the local building department or state website. Note the edition and whether there are local amendments.

Open that edition (or the nearest edition you can read free) and find the chapter that covers your topic using the table of contents or index, using the code's own vocabulary.

Read the whole section, including the paragraph that introduces it, and copy the requirement in your own words.

Look up every defined term the requirement relies on in the definitions chapter and note any that surprised you.

Check for exceptions and, if the value comes from a table, read every footnote that applies.

Follow at least one reference from the section to another section or to a referenced standard and note what it adds.

Write a full citation: code, edition, section, table, footnote or exception used, and any local amendment.

Convert any numeric requirement to the other unit system (SI or US customary) and show the conversion factor you used.

## Why this matters

Codes are the legal minimum for safety in buildings, electrical installations, pressure equipment and much more. Engineers do not memorise them; they **navigate** them: find the clause that governs a situation, read it exactly, follow its references and exceptions, and cite it so a checker or an inspector can verify the decision. Reading a code badly (the wrong edition, a missed exception, a skipped definition) is a common source of rework and, occasionally, of real danger.

## The core idea: model codes, adoption and editions

- A **model code** is written by a standards organisation, for example the **International Building Code (IBC)** from the International Code Council (ICC), or the **National Electrical Code (NEC, NFPA 70)** from the National Fire Protection Association.
- A model code has no legal force on its own. A state, county or city **adopts** it, often a specific edition and often with local **amendments**.
- Codes **reference standards** for technical detail. The IBC, for example, refers to **ASCE 7** (*Minimum Design Loads and Associated Criteria for Buildings and Other Structures*) for loads, and to material standards such as ACI 318 for concrete.

So the first question on any project is: **which code, which edition, with which amendments, does this jurisdiction enforce?** The answer is on the building department's or state's website, or in the project's basis of design. The newest edition is not necessarily the one that applies.

## How a code is laid out

1. **Scope and administration:** what the code applies to and how it is enforced.
2. **Definitions:** defined terms (often in italics) have a precise meaning that may differ from everyday use. "Story", "occupancy" and "dwelling unit" all have exact definitions.
3. **Technical chapters:** organised by topic, numbered hierarchically (chapter 16, section 1607, subsection 1607.1 and so on).
4. **Tables:** many requirements live in tables with footnotes. **Read the footnotes**: they often change the value.
5. **Exceptions:** listed after a requirement; they apply only when every condition in them is met.
6. **Referenced standards:** a chapter listing the exact standard editions the code calls up.

Language matters: **"shall"** is mandatory; **"may"** is permissive. Commentary and handbooks explain intent, but they are not the code.

## A method for finding and applying a clause

1. **Confirm the edition** the jurisdiction has adopted, and any amendments.
2. **Classify the situation** using the code's terms (occupancy, construction type, equipment type).
3. **Search** the index or table of contents with the code's vocabulary, not your own.
4. **Read the whole section,** including the charging paragraph above it, its exceptions and the table footnotes.
5. **Look up every defined term** you are relying on.
6. **Follow references** to other sections or standards.
7. **Record the citation:** document, edition, section, table and any footnote or exception you used.

## Worked example: a floor live load

You need the uniform live load for an office floor in a building designed to the IBC, which in turn points to ASCE 7 for loads.

1. The project basis of design says the jurisdiction enforces a specific IBC edition, which references a specific ASCE 7 edition.
2. Occupancy: business; the space is office use.
3. In the IBC loads chapter, the live-load section points to a table of minimum uniformly distributed live loads by occupancy (Table 1607.1 in recent editions). ASCE 7 has the equivalent table in its live-load chapter.
4. The "office buildings" row lists separate values for offices, for lobbies and first-floor corridors, and for corridors above the first floor. In recent editions the office value is 50 psf, and corridors carry more. Footnotes and nearby sections add requirements, such as an allowance for movable partitions and concentrated loads.
5. Citation: "Office floor live load per [IBC edition] Table 1607.1 / [ASCE 7 edition] live-load table, plus partition allowance per [section]."

If you need SI units: 1 psf = 47.88 Pa, so 50 psf = 2,394 Pa, about 2.39 kPa.

Your value must always come from the edition that applies to your project, not from this lesson. This example shows the method; selecting loads for a real design is the responsibility of the engineer of record.

## Where to read codes

Many model codes can be read free online in a read-only view, for example ICC codes at [codes.iccsafe.org](https://codes.iccsafe.org) and NFPA codes (including NFPA 70) through free access on [www.nfpa.org](https://www.nfpa.org). ASCE 7 is available from [www.asce.org/publications-and-news/asce-7](https://www.asce.org/publications-and-news/asce-7). Access terms change, so check each site (checked on 2026-10-23). Universities and employers often provide full subscriptions.

## Common mistakes

- **Wrong edition.** Using the latest edition when the jurisdiction enforces an older one.
- **Skipping footnotes and exceptions.** The headline value is not the whole answer.
- **Everyday meanings for defined terms.**
- **Citing a handbook or commentary** instead of the code itself.
- **Ignoring local amendments.**

## Quick recap

- Model codes become law when a jurisdiction adopts a specific edition, often with amendments.
- Definitions, tables, footnotes, exceptions and referenced standards all shape the answer.
- Confirm the edition, classify, search with code vocabulary, read the whole section, follow references, cite exactly.
- Real designs use the project's governing edition, under a licensed engineer's responsibility.

## Try it

Open the **Do** tab and find, read and cite a real code clause using a free online code library.


Find, read and cite a code clause: the adopted edition, definitions, tables, footnotes, exceptions and referenced standards.

Reading a code

How to Read a Code Book | ICC Code Books

Gravity Loads (ASCE 7)

## Why this matters

Engineering documents are full of short codes: "ASTM A992", "ACI 318", "ASME B31.3", "IEEE 1584", "NFPA 70". Each points to a standard that thousands of engineers, manufacturers and inspectors rely on, so that a steel beam, a concrete mix or a circuit breaker means the same thing everywhere. Knowing which body publishes what lets you find the right document quickly, specify materials correctly and understand what a reviewer is asking for.

## The core idea: codes, standards and who writes them

- A **standard** is a published document that sets requirements, test methods, specifications or recommended practice, agreed by a committee through a consensus process.
- A **code** is a standard (or a collection) intended to be adopted into law, such as a building code or electrical code.
- A standard becomes mandatory when a code or a contract **references** it. On its own it is voluntary.

In the United States, **ANSI** (the American National Standards Institute) does not usually write technical standards itself; it accredits the organisations that do and approves American National Standards. Internationally, **ISO** and **IEC** (International Electrotechnical Commission) publish standards used worldwide.

## The main bodies and what they cover

| body | known for | examples |
|---|---|---|
| **ASME** (American Society of Mechanical Engineers) | pressure equipment, piping, mechanical components, drawings | Boiler and Pressure Vessel Code (BPVC); B31 piping codes such as B31.1 power piping and B31.3 process piping; Y14.5 dimensioning and tolerancing (GD&T) |
| **IEEE** (Institute of Electrical and Electronics Engineers) | electrical power, electronics, communications | IEEE 1584 arc-flash hazard calculations; IEEE 802 networking (802.3 Ethernet, 802.11 Wi-Fi); the National Electrical Safety Code (NESC, C2) for utility systems |
| **ASTM International** | material specifications and test methods | ASTM A992 structural steel for wide-flange shapes; ASTM C39 compressive strength testing of concrete cylinders; ASTM E8 tension testing of metals |
| **ACI** (American Concrete Institute) | concrete design and construction | ACI 318 *Building Code Requirements for Structural Concrete*; ACI 301 specifications for concrete construction |
| **ASCE** (American Society of Civil Engineers) | loads and civil infrastructure | ASCE 7 minimum design loads (wind, snow, seismic, live) |
| **AISC** (American Institute of Steel Construction) | structural steel design | AISC 360 specification for structural steel buildings |
| **NFPA** (National Fire Protection Association) | fire and electrical safety | NFPA 70 (NEC); NFPA 70E electrical safety in the workplace; NFPA 13 sprinkler systems |
| **UL** (UL Standards & Engagement) | product safety standards and the listing and certification of products by UL Solutions | UL 508A industrial control panels |

## How to read a standard designation

Designations carry information. Take **ASTM A992/A992M-yy**, where `yy` stands for the edition year:

- `A`: ASTM's letter for ferrous metals (C is for cementitious, ceramic, concrete and masonry materials; D for miscellaneous materials such as plastics and soils; E for miscellaneous subjects including many test methods).
- `992`: the standard number.
- `/A992M`: the metric (SI) companion.
- `-yy`: the last two digits of the edition year (for example `-20` would mean 2020).

Many standards are reapproved or revised every few years. A project specification should cite the edition, or the code that references it should fix the edition. As with codes, the edition that applies is the one the contract or the adopted code calls up, not necessarily the newest.

## Worked example: matching standards to a task

| task | where you look first |
|---|---|
| Specify the steel grade for a building's wide-flange beams | ASTM A992 (material), designed to AISC 360 |
| Check what strength test the concrete lab should run on cylinders | ASTM C39 |
| Design reinforced-concrete beams in a US building | ACI 318, as adopted through the building code |
| Design a process-plant piping system | ASME B31.3 |
| Estimate incident energy for an arc-flash study | IEEE 1584, with workplace practices from NFPA 70E |
| Determine snow and wind loads on a roof | ASCE 7 |

## Getting access

Standards are usually sold, and fees and access terms change, so check the publisher (checked on 2026-10-23): [www.asme.org/codes-standards](https://www.asme.org/codes-standards), [standards.ieee.org](https://standards.ieee.org), [www.astm.org](https://www.astm.org), [www.concrete.org](https://www.concrete.org), [www.asce.org/publications-and-news/asce-7](https://www.asce.org/publications-and-news/asce-7) and [www.nfpa.org](https://www.nfpa.org). University libraries and employers often hold subscriptions; NFPA and ICC offer free read-only access to many codes.

## Common mistakes

- **Confusing the material standard with the design standard.** ASTM A992 says what the steel is; AISC 360 says how to design with it.
- **Citing no edition** in a specification.
- **Assuming a standard is law.** It is mandatory only when referenced by an adopted code or a contract.
- **Using a summary table from the internet** instead of the standard itself.

## Quick recap

- Standards are consensus documents; codes are standards meant for adoption into law.
- ASME: pressure equipment and piping. IEEE: electrical, electronics and communications. ASTM: materials and tests. ACI: concrete. Also ASCE 7 loads, AISC steel, NFPA fire and electrical safety, UL product safety.
- Read designations for the number, metric version and edition year.
- The edition that applies is set by the adopted code or the contract.

## Try it

Open the **Do** tab and take the quiz to match standards bodies to real engineering tasks.


Match ASME, IEEE, ASTM, ACI and other standards bodies to the documents engineers use, and read a standard designation.

Standards bodies

What is a standard? A quick guide to standards and why they matter

Code vs Standard: What’s the Difference? (ASME/API Explained for Engineers)

Set up a comment log with columns: number, line, comment, originator's response, status.

Check the inputs: does each one have a source? Note anything you would confirm against the drawing or table.

Make your own rough estimate of the moment and deflection before checking the arithmetic line by line.

Check each line's arithmetic and units. Mark agreed lines with a tick (or yellow) and errors in red.

Write a specific comment for each error, with the correct value: you should find at least an arithmetic error and a unit-conversion error.

Recompute the deflection with the corrected values and state whether the conclusion (NG, increase beam size) changes.

Note any process issues on the cover (for example the checker and date fields).

Swap roles: write the originator's response to each comment, then back-check that each correction is right and sign the check.

## Why this matters

Every engineer makes mistakes: a dropped factor of ten, a load copied from the wrong drawing, a code clause from the wrong edition. Professional practice does not assume perfection; it builds **checking** into the process so that errors are caught before documents are issued. Firms with strong quality systems issue fewer revisions, have fewer claims and earn more trust. As a junior engineer you will be checked constantly, and soon you will check others' work.

## The core idea: QA plans the process, QC checks the product

- **Quality assurance (QA)** is the *system*: procedures, templates, required reviews, checklists, training and records that make good work likely. It is about prevention.
- **Quality control (QC)** is the *checking* of a specific deliverable against requirements: this calc, this drawing set, this specification. It is about detection.

A typical firm's QA procedure defines which deliverables need which checks, who is qualified to check, how checks are recorded, and when a document may be issued.

## Levels of review

| level | who | what |
|---|---|---|
| **Self-check** | the originator | re-read, units, arithmetic, sanity check against a rough estimate |
| **Independent check** | a qualified checker who did not do the work | inputs, assumptions, method, arithmetic, conclusions; often line by line |
| **Discipline review** | discipline lead or engineer of record | design intent, code compliance, judgement |
| **Interdisciplinary coordination** | all disciplines together | clashes and interfaces (structure versus ducts, electrical loads versus mechanical equipment) |
| **Peer review** | an independent senior engineer, sometimes outside the firm | approach and key decisions on complex or high-consequence work; sometimes required by the authority having jurisdiction |

## How a check is run

A disciplined check follows a loop, often called **check and back-check**:

1. **Originator** issues the calc or drawing for checking with a transmittal: what to check, what references apply, what has changed since any previous check.
2. **Checker** reviews against the references, without redoing the work in the same way. Good checkers use an *independent method* where possible: a different formula, a quick hand estimate, software against a hand calc, or a known textbook case.
3. **Checker marks up.** A common convention (firms differ, so follow yours): yellow highlight for "checked and agreed", red for corrections, and another colour for questions or comments. Every comment is specific and cites the source.
4. **Comments are logged** in a comment-resolution sheet: number, location, comment, originator's response, status.
5. **Originator responds** to every comment: agree and fix, or explain why no change is needed.
6. **Checker back-checks** that each fix was made correctly and that no new errors were introduced, then signs and dates.
7. The document is issued only when every comment is closed.

## Worked example: two errors a checker should catch

An originator's calc reads:

```text
Uniform load w = 2 kip/ft, span L = 20 ft
M_max = w L^2 / 4 = 2 × 400 / 4 = 200 kip-ft
M_max = 200 kip-ft × 0.4448 = 89.0 kN·m
```

The checker's independent estimate and comments:

1. **Formula.** For a simply supported beam under uniform load, `M_max = w L^2 / 8`, giving `2 × 400 / 8 = 100 kip-ft`. (`w L^2 / 4` does not apply here; `P L / 4` is the midspan moment for a single point load P.) *Red: change to w L^2 / 8; M_max = 100 kip-ft.*
2. **Unit conversion.** 0.4448 is not the right factor. 1 kip = 4.448 kN and 1 ft = 0.3048 m, so 1 kip-ft = 4.448 × 0.3048 = 1.356 kN·m. *Red: 100 kip-ft × 1.356 = 135.6 kN·m.*

Three lines, two errors: the first doubles the moment, and the second shrinks the converted value by a factor of about three. Neither would crash a program or look obviously wrong at a glance. This is why checks exist.

## What a checker looks at

- **Inputs:** do they match the latest drawings, vendor data and criteria? Are sources cited?
- **Assumptions:** stated, reasonable and consistent with the design?
- **Method and references:** right formula, right code edition, applicable limits?
- **Arithmetic and units:** spot-check by hand; check that units cancel.
- **Reasonableness:** does the answer make sense compared with a rule of thumb or a similar past project?
- **Conclusions:** do they follow from the results, and are they carried to the drawings?

## Common mistakes

- **Checking by re-reading.** Reading the same steps again tends to repeat the same error. Use an independent method.
- **Vague comments.** "Looks off" gives the originator nothing to act on.
- **No back-check.** A fix that introduced a new error goes out unchecked.
- **Checking your own work as the "independent" checker.**
- **Taking comments personally.** A check is about the document, not the person. Thank your checker.

## Quick recap

- QA is the system that prevents errors; QC is the checking that detects them.
- Reviews range from self-check to independent check, discipline review, coordination and peer review.
- Run checks as a loop: issue, mark up, log, respond, back-check, sign.
- Use independent methods and reasonableness checks; cite sources in every comment.

## Try it

Open the **Do** tab and run a peer check on a short calculation with planted errors, using a comment log.


Run an independent check of a calculation with a comment log and back-check, and tell quality assurance from quality control.

QA/QC and peer review

Quality Assurance vs Quality Control: What’s the Difference?

Find, read and cite code clauses, match standards bodies to their documents, and run QA/QC checks and peer reviews.