Construction drawings are sorted three ways. By discipline, a set runs from general (G) and civil (C) through structural (S), architectural (A), fire protection, plumbing, mechanical, and electrical. By phase, they move from schematic design through construction documents, permit, bid, IFC, shop drawings, and record drawings. By view, each one is a plan, elevation, section, detail, schedule, or diagram.
Last reviewed October 2026
Helonic, an AI drawing review platform, reads all three at once: it knows an M-201 is a mechanical plan, checks which issue the sheet belongs to, and compares it with the sheets it should agree with. This page is the map, with a link to a reading guide for each type.
| Sorted by | What it tells you | Examples |
|---|---|---|
| Discipline | Who drew it and which trade builds from it | A, S, M, E, P, FP |
| Phase | How complete it is and what it can be used for | SD, DD, CD, permit, bid, IFC, record |
| View | Which way you're looking at the building | Plan, elevation, section, detail, schedule |
Each discipline gets a letter, and that letter starts every sheet number in its part of the set. The order below follows the Uniform Drawing System in the National CAD Standard, which most US sets loosely follow. The standard uses F for fire protection, but many sets use FP.
| Prefix | Discipline | What the set contains | Guide |
|---|---|---|---|
| G | General | Cover sheet, sheet index, code summary, symbols, abbreviations, general notes | Construction abbreviations |
| C | Civil | Site plan, grading, utilities, paving, stormwater, erosion control | How to read civil drawings |
| L | Landscape | Planting, hardscape, irrigation, site furnishings | How to read landscape drawings |
| S | Structural | Structural notes, foundation and framing plans, sections, connection details, schedules | How to read structural drawings |
| A | Architectural | Floor plans, RCPs, roof plan, elevations, sections, details, door and window schedules | How to read architectural drawings |
| I | Interiors | Finish plans, furniture plans, interior elevations, finish schedules | Finish schedule guide |
| FP | Fire protection | Sprinkler layout, standpipes, fire pump, riser details, hydraulic design criteria | How to read fire sprinkler drawings |
| P | Plumbing | Domestic water, sanitary, vent, storm, and gas plans, riser diagrams, fixture schedule | How to read plumbing drawings |
| M | Mechanical | HVAC duct and piping plans, equipment schedules, controls, sequences of operation | How to read mechanical drawings |
| E | Electrical | Power and lighting plans, one-line diagram, panel schedules, fire alarm on some projects | How to read electrical drawings |
| T | Telecommunications | Data and voice outlets, pathways, telecom rooms, AV and security on some projects | How to read telecom drawings |
Larger projects add more letters: V for survey, B for geotechnical, Q for equipment such as food service. For how sheets are numbered and ordered inside each discipline, see drawing types and sheet organization by discipline. The HVAC drawings guide and MEP drawings guide cover the engineering sheets in more depth.
The phase tells you what a drawing can be used for. The first three phases are the design phases named in AIA owner-architect agreements. The rest are issues of the finished documents, plus the drawings the trades and the contractor produce.
| Phase | What it is | Guide |
|---|---|---|
| Schematic design (SD) | Early plans, massing, and sections from the architect that set the layout and size. Little engineering yet. | |
| Design development (DD) | Systems and materials chosen; structural and MEP layouts drawn; enough detail for a reliable estimate. | |
| Construction documents (CD) | The full coordinated set with details, schedules, and specifications, drawn to be built from. | Drawing set phases guide |
| Permit set | The CDs issued to the building department for plan review. Corrections from plan check often follow. | Permit set checklist |
| Bid set | The CDs issued for pricing, with addenda during bidding. Sometimes the same issue as the permit set. | |
| Issued for construction (IFC) | The set the field builds from, with permit comments and addenda folded in. | Permit set vs IFC set |
| Shop drawings | Drawn by subcontractors and fabricators to show how their work is made and installed. Reviewed by the design team. | How to review shop drawings |
| Coordination drawings | Composite trade layouts that route duct, pipe, conduit, and sprinkler through the same space before install. | Coordination drawings |
| Record and as-built drawings | The contractor's field markups of what was actually built, and the record set compiled from them at closeout. | As-built drawings guide |
The phase is printed on the cover sheet and in each title block, usually as an issue name and date. Two sets that look identical can be different issues, so check the title block before you compare them.
Within any discipline and phase, a sheet holds one or more views. The view tells you which way you're looking and how much of the building you're seeing.
| View | What it is | Guide |
|---|---|---|
| Plan | A horizontal cut looking down: floor, site, roof, foundation, and framing plans, plus enlarged plans of busy rooms. | How to read a site plan |
| Reflected ceiling plan (RCP) | The plan looking up: ceiling heights, grid, lights, diffusers, and sprinkler heads. | How to read reflected ceiling plans |
| Elevation | A straight-on view of an exterior face or an interior wall, showing heights and materials. | |
| Section | A vertical cut through the building or one wall that shows how the parts stack. | Building section vs wall section |
| Detail | An enlarged view of one condition, such as a roof edge, a footing, or a door head. | How to read detail sheets |
| Schedule | A table keyed to tags on the plans: doors, windows, finishes, equipment, panels. | How to read a door schedule |
| Diagram | A non-scaled view of how a system connects, such as a riser diagram or an electrical one-line. | Plumbing riser diagram guide |
Electrical one-line diagrams have their own guide at electrical single-line diagrams. Plumbing sets also use isometric views, which show piping in three dimensions without a true scale.
Take sheet A-301 in an IFC set. The A says architectural. Under the Uniform Drawing System the 3 says sections, and 01 is the first sheet of them. The title block says the issue is IFC and gives its date.
You need all three to know whether a sheet answers your question. A wall section on A-301 from the permit set may be superseded by a later revision. A detail on S-501 governs the structure, while the architectural detail of the same corner governs the finish. Reading order for a whole set is in how to read blueprints.
The field builds from the current IFC set plus every revision, bulletin, and ASI issued since. Estimators price from the bid set and its addenda. Plan reviewers check the permit set. Mixing them up is one of the easiest ways to build something that was already changed.
Before you review, confirm every sheet in the set carries the same issue name, or a later revision. One sheet left at an older issue is enough to put the wrong detail in the field.
Helonic's revision comparison shows what changed between two issues of the same sheet, and drawing set completeness checks that the disciplines you expect are all present. For the full review process, see how to review construction drawings.
Practitioner insight
“Half my questions from new hires are really 'which set is this?' They'll find a detail in the bid set that we revised three bulletins ago and ask why the field didn't build it.”
Conversations with general contractor project managers running document control on active building projects.
Manas is the co-founder and CTO of Helonic, where he leads engineering and AI research for construction drawing analysis. He works directly with structural, MEP, civil, and fire protection engineers to translate the way they review drawings into AI systems that flag the issues that actually matter in the field. Before Helonic, he built machine learning pipelines for technical document understanding and has spent the last several years interviewing licensed design engineers and discipline leads to ground product decisions in real practice rather than industry assumptions.
How this page was researched: Discipline designators and sheet type digits follow the Uniform Drawing System in the National CAD Standard. Design phase names follow AIA owner-architect agreements. Firms adapt both, so the article points readers to each set's index and title block.
Last reviewed by Manas Gandhi · October 2026
Related references for drawing sets, phases, and sheet types.
The reading order for a full drawing set.
What changes from SD to DD to CD.
How trades route systems through shared space.
Field markups and the record set at closeout.
How sheet numbers and sheet order work.
A systematic approach to catching drawing errors before construction.