On construction drawings, VIF (also written V.I.F.) means “verify in field,” TYP means “typical,” and NIC means “not in contract.” They are standardized shorthand—alongside terms like UON and O.C.—that let a drafter state a condition once instead of writing it out on every sheet. Misreading one, or missing where a project’s own general notes redefine it, is a common and avoidable source of RFIs and field errors.
Why drawings rely on abbreviations and symbols
Most firms and public agencies keep a project- or office-specific legend sheet, but the underlying vocabulary is fairly consistent across the industry because it traces back to a small number of shared references. The United States National CAD Standard, maintained by the National Institute of Building Sciences with the American Institute of Architects and the Construction Specification Institute, publishes a dedicated terms-and-abbreviations module. Public agencies also publish their own versions for the sets submitted to them; San Diego’s Citywide CADD and Drafting Standards is one public example, with its own symbols and abbreviations sections. Both pages were live when checked on 2026-09-16.
None of that guarantees one universal shorthand. A project’s own general notes and legend sheet govern when they define a term differently, and a single detail can redefine an abbreviation for just that sheet. Treat the table below as the common default, not a substitute for the legend on the set in front of you. Fire safety symbols on alarm, sprinkler, evacuation, and signage drawings have their own standard; the NFPA 170 symbols guide shows how to check them against the legend.
What VIF means in construction
VIF, sometimes written V.I.F., stands for “verify in field.” It is placed next to a dimension or condition the designer could not confirm from the office, usually because it depends on existing construction or on work built earlier in the job. The note shifts responsibility for that one number to whoever builds from it: the contractor or installer measures the actual condition on site before fabricating or ordering anything that depends on it.
- Where it shows up: renovation and addition work tying into existing walls, slabs, or openings; storefront, casework, and other items fabricated off site to fit a built opening; and details that meet existing utilities or grades.
- What to do with it: measure the condition, compare it with the drawn number, and raise a question or RFI if the two disagree by enough to change the work.
- What it is not: an invitation to redesign. VIF confirms a dimension; it does not change who decides how the design responds if the field condition is different.
Common construction drawing abbreviations and symbols
These are the abbreviations that come up most often across disciplines. Confirm the project’s own legend before assuming one applies unchanged.
| Abbreviation | Meaning | Typically appears on |
|---|---|---|
| NIC | Not in contract — shown for reference but excluded from this scope of work | Plans, general notes |
| TYP | Typical — this condition repeats at similar locations without being redrawn or redimensioned each time | Plans, details |
| VIF | Verify in field — confirm the dimension or condition on site before fabricating or ordering material | Details, plans |
| UON | Unless otherwise noted — the note applies everywhere it could, except where a drawing states something different | General notes, details |
| EQ | Equal — a series of spaces or dimensions are meant to be the same size; the exact value is calculated, not stated | Plans |
| O.C. | On center — spacing measured from the center of one repeated element to the center of the next | Plans, schedules, details |
| DN | Down — a stair, ramp, or level change going downward | Plans |
| UP | Up — a stair or ramp going upward | Plans |
| EX. / EXIST. | Existing — the element is already in place and is not part of the new work | Plans, elevations, site plans |
| N.T.S. | Not to scale — the drawing is not scaled accurately; use the noted dimensions instead of measuring the page | Details, plans |
| AFF | Above finished floor — a height measured from the finished floor rather than the structural slab | Elevations, details, schedules |
| CLR | Clear — the clear dimension between two surfaces, not to a centerline or a face of stud | Details |
| SIM | Similar — the referenced detail applies with noted differences, not exactly as drawn | Details |
| CONT | Continuous — the element runs without a break across the condition shown | Details, sections |
| R.O. | Rough opening — the framed opening size before finish materials, doors, or windows are installed | Schedules, details |
| REF | Reference — points to information carried on another sheet rather than repeating it here | Details, plans |
Where these abbreviations typically live
The right-hand column above is a starting point, not a rule; the same abbreviation can turn up on more than one sheet type. A few patterns hold often enough to be useful.
- Plans carry the shorthand that saves space next to a symbol: TYP beside a repeated window head, EQ between three bays, DN and UP at a stair — worth checking against the stair riser and tread calculator once you know which direction the run goes.
- Details carry the shorthand that qualifies a dimension or a condition: VIF where a field measurement governs, CLR where the dimension runs to a face rather than a centerline, SIM where the drawn detail is close but not identical to the condition being built.
- Schedules carry the shorthand that shortens a repeated column heading, such as R.O. for “rough opening” or AFF for “above finished floor.”
- General notes and legends are where a project defines what its own abbreviations mean, and where a firm’s office standard can differ from the table above for a specific term.
A missed VIF is a common, avoidable field problem: if a detail assumes a dimension will be confirmed on site and the fabricator instead treats the drawn number as final, the built condition and the drawing can disagree before anyone notices. Reading the abbreviation, not just the number beside it, is what prevents that.
Where Groundbook fits
Groundbook’s document review already reads the legend sheets, general notes, and abbreviation lists in an uploaded set as part of reading the whole package, and can flag where a tag, note, or symbol is used inconsistently across sheets, such as a term defined one way on the cover sheet and used differently on a detail. That is part of the existing symbols-and-legends check in a Groundbook review, not a new capability, and a flagged inconsistency is a question for your team to confirm rather than an automatic correction.