Construction jargon explained: site terms in plain English

In your first weeks about a third of what people say to you will be words you do not know, and asking every time is impractical. This is the vocabulary of a US construction site, grouped so you can find things, with the terms that actually matter to you flagged. Learn the people, the paperwork and the money terms first, because those are the ones where not knowing costs you something. Everything here appears on a normal job.‍‌‌‌‌‌​​​​​‌‌​‌‌​‌‌​​​​‌‌‌‌​​‌‌‌​‍

People and roles

• GC, general contractor. The company running the whole job for the owner.
• Sub, subcontractor. A specialist company doing one trade under the GC. Most trades people work for a sub.
• Super, superintendent. The GC's person on site running the day and the schedule.
• PM, project manager. Runs the job from the office: money, schedule, submittals.
• Foreman. Runs a crew. Yours is who you take direction from.
• Owner. The person or company paying for the building. Also called the client.
• AHJ, authority having jurisdiction. The local body that enforces the code, in practice usually the building department and its inspectors. How do I work with the building inspector (the AHJ)?
• Competent person. An OSHA role, not a job title: someone able to spot hazards and with authority to correct them. What is a "competent person" and why every job needs one
• Journeyman, master. Rungs on a trade licensing ladder. Apprentice, journeyman, master: how long does it take to the top?

Paperwork and drawings

• Plans, drawings, prints. The drawn design. "Blueprints" is old but everyone still says it.
• Specs, specification. The written half of the design: materials, standards, and how things must be done. When the plans and the specs disagree, somebody has to ask.
• Submittal. Product data or samples sent up for approval before you buy or install.
• Shop drawing. A detailed fabrication drawing produced by whoever is making something.
• RFI, request for information. A written question when the drawings are unclear or contradictory. The formal way of asking rather than guessing.
• Takeoff. Measuring quantities off the drawings so a job can be priced or ordered. How to do a material takeoff from a set of plans
• As-built. The drawings updated to show what was actually built, handed over at the end.
• Punch list. The list of small items to fix before the job is signed off. The last two percent that takes twenty percent of the time.
• CO, certificate of occupancy. The document saying a building may legally be occupied.
• Change order. A signed agreement covering work outside the original scope, with a price. Change orders: how to actually get paid for extra work
• Scope. What your price covers. The most important word on any job. Scope of work and exclusions

Money terms, and these are the ones to learn first

• W-2 and 1099. How you are paid and taxed. A W-2 employee has FICA withheld and overtime protection; a 1099 subcontractor pays both halves of FICA and has neither. 1099 vs W-2: which are you really?
• W-9. The form a business asks a subcontractor to complete so it can issue a 1099.
• Per diem. A daily allowance for working away from home.
• Prevailing wage, Davis-Bacon. A wage and fringe rate set by law on many public jobs, which you must be paid on that job whatever your normal rate. What is prevailing wage, and does it apply to my job?
• Certified payroll. The weekly payroll report required on those jobs, usually on form WH-347. Certified payroll: filling in the WH-347 without losing the job
• Retainage. A slice of money earned but held back until well after the work is finished. Retainage and prompt pay
• Backcharge. When somebody deducts from your money for something they say you caused. Always get it in writing.
• Mechanic's lien. A legal claim against a property when you have not been paid. Not been paid? The mechanic's lien is your strongest move.
• Prelim, preliminary notice. A notice served early on many jobs to keep lien rights alive. Miss it and the lien can be gone before there is a dispute. The preliminary notice
• COI, certificate of insurance. Proof of insurance, usually demanded before you can start. Certificate of insurance and additional insured
• Progress billing, draw. Being paid in stages as work advances rather than at the end. Deposits and progress billing

The building itself

• Footing and foundation. What the building sits on, and the wall or slab above it.
• Slab. A concrete floor poured on the ground.
• Rebar. Steel reinforcing bar cast into concrete.
• Stud, plate, header, joist, rafter, truss. The framing members: vertical, horizontal top and bottom, over an opening, floor or ceiling, roof, and factory-made roof structure.
• Blocking. Short pieces between framing members to support or fix something later.
• Sheathing. The board skin over framing, usually plywood or OSB.
• Rough-in. First fix: everything installed before the walls close up.
• Trim out, finish out. Second fix: fixtures, devices and trim after the walls are finished.
• Dry-in. The point where the building is weather-tight.
• Flashing. The metal or membrane that keeps water out of a joint. Where roofs actually leak.
• Soffit and fascia. The underside of an overhang and the board at its edge.
• Grade. Ground level, or the process of leveling ground.
• MEP. Mechanical, electrical and plumbing, as a group.
• Egress. A legal way out. Does a bedroom need an egress window, and how big?
• Setback. How far a building must sit from a boundary.

Trade shorthand you will hear

• Square (roofing). 100 square feet of roof surface. A 20-square roof is 2,000 square feet.
• Level 4 and Level 5 (drywall). Finish standards. Level 5 adds a full skim coat and is specified where high-gloss paint or raking light would show any imperfection.
• Type X. Fire-rated drywall, required on fire-rated assemblies such as the wall between an attached garage and living space.
• Romex and EMT. Common shorthand for sheathed cable and metal conduit.
• Home run. A circuit run straight back to the panel.
• Load calc. The calculation that sizes an electrical service or a heating and cooling system.
• Blue tape. Walking a job marking defects, usually near the end.
• Mobilization. Getting your people and equipment on site and set up.
• Demo. Demolition, the taking-out phase.
• Critical path. The chain of tasks that decides the finish date. If you are on it, everyone is watching you.

Safety and compliance terms

• OSHA. The federal workplace safety agency, and by extension its rules.
• OSHA 10 and OSHA 30. Safety training cards, 10-hour for workers and 30-hour for supervisors. Not a trade license. Do I need an OSHA 10 or 30 card?
• Focus Four. The four hazards that cause most construction deaths: falls, struck-by, caught-in or between, and electrocution. Formerly the Fatal Four, same hazards. The Focus Four
• PPE. Personal protective equipment. Required PPE is provided and paid for by the employer, with narrow exceptions. PPE on site: what's required and who pays for it
• SDS. Safety data sheet, the hazard information for a chemical product. It replaced the older MSDS. Hazard communication: SDS, labels, and your right to know
• LOTO, lockout tagout. Isolating an energy source so a machine cannot start while somebody is working on it.
• JHA or JSA. Job hazard analysis: writing down a task, its hazards and its controls before starting. Job Hazard Analysis (JHA) Builder
• Toolbox talk. A short safety briefing on one topic. Toolbox Talk Sheet
• 300 log. The OSHA log of recordable work injuries and illnesses. OSHA recordkeeping: the 300 log and reporting a serious injury
• Multi-employer site. A site with several companies on it, where OSHA can cite more than one for the same hazard. Who's on the hook for safety on a shared site?

The two rules for using any of this

Ask when it matters. Nodding along to a word you do not know is fine in a conversation about somebody's weekend and dangerous in an instruction. If the sentence tells you what to do, make sure you understood it.

Write down the ones you keep hearing. By the end of a month the list is short, and the second month sounds completely different from the first.

Where to go next in this section

• Your first day on site: what to expect and what to ask, where most of this vocabulary first appears.
• What nobody tells you before you start in construction, the honest picture around it.
• Site orientation and safety training: what you must be told, for the safety terms in context.
• Your first paycheck explained, for the money terms in context.
• The trade math you actually use, for the arithmetic behind the measurements.
• The trades, and what each one takes, for the trade-specific vocabulary beyond this.

Common questions

What does rough-in mean in construction?

Rough-in is the stage where the services are installed before the walls are closed up: the wiring, pipework and ductwork run through open framing. It is inspected before anything is covered, which is why the rough inspection is a scheduling event that everybody waits on. The matching term is trim out or finish out, which is the later stage where fixtures, devices and trim go in after the walls are finished. If someone says the job is at rough-in you know the building is framed, open, and not yet inspected or covered.

What is the difference between a W-2 and a 1099 in construction?

A W-2 means you are an employee: your employer withholds federal income tax and FICA, pays a matching FICA share of 7.65 percent, and you have overtime protection and unemployment cover. A 1099 means you are being treated as an independent subcontractor: nothing is withheld, you pay both halves of FICA at 15.3 percent yourself, and you have neither overtime protection nor unemployment. Being handed a 1099 does not make it correct, because the test is how the relationship actually works rather than what the paperwork says, and misclassification is common in construction.

What is a punch list?

The punch list is the list of small outstanding items that have to be fixed or finished before a job is accepted and signed off. Typically it is generated by walking the finished work and noting defects, sometimes marked physically with blue tape, which is where the phrase "blue tape walk" comes from. It is the last two percent of the job that regularly takes a disproportionate amount of the time, and on many contracts final payment and the release of retainage depend on clearing it, which is why it matters far more than its size suggests.

What does the AHJ mean?

AHJ stands for authority having jurisdiction: the local body that adopts and enforces the building code where you are working, which in practice usually means the building department and its inspectors. It matters because the code is not uniform across the country. Different jurisdictions adopt different editions with their own local amendments, so what passed inspection in one county is not automatically acceptable in the next. When people say to check with the AHJ, they mean the local building department is the authority on what is actually required here.

What is retainage?

Retainage is a portion of money you have already earned that is held back by whoever is paying you, and released only well after the work is complete. It is standard on commercial and public work and it exists to give the paying party security that the job will be finished properly. For a worker it usually shows up as a reason your employer is slow to be paid; for a subcontractor it is a direct cash-flow problem, because you have paid your own labor and materials in full while a slice of your money sits somewhere else. Most states regulate how much can be held and when it has to be released.

The honest bit

• This is a working vocabulary, not a dictionary. Terms vary by region, by trade and by company, and some of these mean slightly different things on a commercial job than on a house.
• The definitions here are the plain-English versions. Where a term has a legal meaning, such as competent person, prevailing wage, retainage or mechanic's lien, the linked guide is the one to rely on rather than the one-line entry.
• Where a term carries a legal deadline, particularly preliminary notice and lien filing, the deadline is set by your state and missing it can end the right entirely.
• This is general guidance, not legal advice.

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