Knowing how a drawing set is put together saves hours on every bid. This guide walks through the drawing types, how sheets are numbered, how a set changes from schematic design to issued for construction, and the other documents that sit alongside the drawings, including the difference between a bill of quantities and a bill of materials.
Drawing Disciplines and Sheet Designators
Most US drawing sets follow the US National CAD Standard, which assigns a letter to each discipline. The order below is the typical order of sheets in a set:
| Designator | Discipline | What it covers |
|---|---|---|
| G | General | Cover sheet, sheet index, code summary, life safety plans, general notes |
| C | Civil | Grading, drainage, utilities, paving and site layout |
| L | Landscape | Planting, irrigation and hardscape |
| S | Structural | Foundations, framing plans, beam and column schedules, connection details |
| A | Architectural | Floor plans, elevations, sections, wall types, door and finish schedules, details |
| I | Interiors | Interior elevations, furniture and finish plans (on larger projects) |
| F / FP | Fire protection | Sprinkler layouts, standpipes and fire pump details |
| P | Plumbing | Water, waste and vent layouts, risers, fixture schedules |
| M | Mechanical | HVAC duct and piping, equipment schedules, controls |
| E | Electrical | Power, lighting, one-line diagrams, panel schedules |
| T | Telecommunications | Data, voice, security and audio-visual systems |
How Construction Sheets Are Numbered
A sheet number such as A-201 tells you more than which page you are on. The letter is the discipline, the first digit is the sheet type, and the last digits are the sequence:
| First digit | Sheet type | Example |
|---|---|---|
| 0 | General: legends, notes, symbols | A-001 |
| 1 | Plans | A-101 First floor plan |
| 2 | Elevations | A-201 Exterior elevations |
| 3 | Sections | A-301 Building sections |
| 4 | Large-scale views (enlarged plans) | A-401 Enlarged restroom plans |
| 5 | Details | A-501 Wall details |
| 6 | Schedules and diagrams | A-601 Door and finish schedules |
| 9 | 3D representations | A-901 Isometric views |
Sheet type designators per the US National CAD Standard. Many firms use their own variations.
The Main Types of Construction Drawings
- Site plan: the building on its lot, with property lines, setbacks, parking, utilities and grading.
- Floor plans: a horizontal cut through each level showing walls, doors, windows, rooms and dimensions.
- Reflected ceiling plans (RCPs): the ceiling as if seen in a mirror on the floor, showing ceiling types, heights, lights and diffusers.
- Roof plan: slopes, drains, curbs, rooftop equipment and roofing system.
- Elevations: flat views of each exterior face, or interior walls, showing heights, materials and openings.
- Sections: vertical cuts through the building or a wall, showing how the assembly goes together from foundation to roof.
- Detail drawings: enlarged views of specific conditions, such as a window head, a parapet or a stair handrail, at scales like 1-1/2″ = 1′-0″.
- Schedules: tables for doors, windows, finishes, hardware, equipment, fixtures and structural members.
- Isometric drawings: 3D views, common for plumbing risers, ductwork and complex assemblies.
- Structural drawings: foundation and framing plans, with beam, column and footing schedules and connection details.
- MEP drawings: mechanical, electrical and plumbing layouts, risers and schedules.
For estimators, the schedules and details are where much of the money hides. A wall type that looks simple on the floor plan may turn out to be a two-hour rated assembly once you read the partition schedule.
Drawing Sets by Design Phase
A drawing set grows in detail as design progresses. Each stage is issued for a different purpose:
| Phase / issue | Typical completion | Purpose |
|---|---|---|
| Schematic design (SD) | About 15% to 30% | Overall layout, massing and systems; early budget pricing |
| Design development (DD) | About 50% to 65% | Materials, systems and major dimensions fixed; more reliable estimates |
| Construction documents (CD) | 90% to 100% | Full detail for permitting, bidding and construction |
| Permit set | Varies | Submitted to the building department for plan review |
| Bid set | 100% CDs plus addenda | The documents contractors price |
| Issued for construction (IFC) | Final | Approved for building, after permit comments and bid revisions |
| Conformed set | Final | Bid set updated to include all addenda, so the field works from one clean set |
| Record / as-built drawings | After completion | What was actually built, including field changes |
Completion percentages are typical ranges, not fixed rules.
The difference between schematic design and design development matters for pricing. An SD estimate is a budget built on square foot costs and assumptions. A DD estimate can be built from real quantities, but it still needs allowances for details that are not drawn yet.
What Are Construction Documents?
“Construction documents” means more than the drawings. A complete set usually includes:
| Document | What it is |
|---|---|
| Drawings | The graphic description of the work, organized by discipline |
| Project manual / specifications | Written requirements for materials, products, workmanship and procedures, organized by CSI MasterFormat division |
| Owner-contractor agreement | The contract itself, often an AIA A101 or similar |
| General and supplementary conditions | Rights, responsibilities, payment, changes and claims, often AIA A201 plus project-specific changes |
| Addenda | Changes and clarifications issued during bidding |
| Bid documents | Instructions to bidders, bid forms, bonds and alternates |
| Reports | Geotechnical, environmental and survey information, sometimes included for reference only |
Construction Documents Through the Project Lifecycle
The document set keeps growing after the contract is signed. Here is what a typical project produces at each stage:
| Stage | Documents | Purpose |
|---|---|---|
| Design and bidding | Drawings, specifications, contract and general conditions, bid forms, addenda, geotechnical and survey reports | Define the work and the deal |
| Preconstruction | Permits, baseline schedule, cost estimate and schedule of values, insurance and bonds, subcontracts | Plan the work and set the budget |
| Construction | RFIs, shop drawings and other submittals, change orders, daily logs, meeting minutes, inspection reports, pay applications | Track questions, changes, progress and payment |
| Closeout | As-built drawings, O&M manuals, warranties, punch lists, lien waivers, certificate of occupancy | Hand over the building and close the contract |
When drawings and specs conflict, the contract usually sets an order of precedence. A common rule is that specifications govern over drawings, and larger-scale details govern over smaller-scale plans, but the actual contract language is what counts.
BOQ vs. BOM: Bill of Quantities vs. Bill of Materials
Both are quantity lists, but they serve different purposes and audiences:
| Bill of quantities (BOQ) | Bill of materials (BOM) | |
|---|---|---|
| What it lists | Items of work with measured quantities and units, such as cubic yards of concrete or square feet of drywall | The specific materials and components needed to build or fabricate something |
| Who prepares it | Estimator or quantity surveyor, usually for the owner or contractor | Fabricator, manufacturer, supplier or trade contractor |
| Main use | Tendering and pricing: every bidder prices the same quantities | Procurement and fabrication: what to buy, cut or assemble |
| Includes labor? | Priced rates usually include labor, materials and equipment | Usually materials only |
| Common where | UK, Middle East, Asia, Australia and international work | Manufacturing, fabrication and procurement everywhere |
On most US projects, owners do not issue a formal BOQ. Each bidder does its own quantity takeoff, and the contractor later breaks the price into a schedule of values for billing. On international and public work, a BOQ is often part of the tender documents. Our guide to construction tender document preparation covers how BOQs and bid packages are put together.
How Estimators Read a Drawing Set
- Start with the sheet index and general notes to confirm the set is complete and see which codes and standards apply.
- Read the code summary for construction type, occupancy and sprinkler status, which drive rated assemblies.
- Check the revision block and clouds on every sheet, and log all addenda.
- Read schedules before measuring plans, so each wall, door and finish is priced as the right type.
- Cross-check disciplines: architectural ceiling heights against mechanical duct sizes, structural openings against MEP penetrations.
- Read the specs for products, testing and requirements that never appear on the drawings.
Help With Drawings and Takeoffs
Design Estimation prepares CAD drawings, as-built and shop drawings, and quantity takeoffs and estimates from full construction document sets for contractors across the US. See our CAD drawing services or send your drawing set for a quote.
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Frequently Asked Questions
Quick answers to the questions contractors ask us most.
What are the types of construction drawings?
The main types are site plans, floor plans, reflected ceiling plans, elevations, sections, details and schedules. These are produced for each discipline: civil, structural, architectural, mechanical, electrical, plumbing and fire protection.
What are construction documents?
Construction documents are the drawings, specifications and contract documents that define a project. They include addenda and general conditions, and they are what contractors bid and build from.
What does IFC mean on drawings?
IFC means “issued for construction.” It marks the drawing set approved for building, after permit comments and bid revisions have been incorporated.
What is a conformed set of drawings?
A conformed set is the bid set updated to include all addenda and bid-phase changes. It gives the field one clean, current set instead of the original drawings plus separate addenda.
What is the difference between schematic design and design development?
Schematic design sets the overall layout and concept; design development fixes materials, systems and major dimensions. SD supports budget pricing, while DD supports more detailed estimates.
What is a detail drawing in construction?
A detail drawing is an enlarged view of a specific condition, such as a wall base, window head or connection. It shows exactly how materials meet, at a larger scale than the plans.
What is the difference between BOQ and BOM?
A BOQ lists measured quantities of work for pricing; a BOM lists materials and components for purchasing or fabrication. BOQs are common in tenders outside the US, while BOMs are used by fabricators and suppliers everywhere.
What are building drawings?
Building drawings are the plans, elevations, sections and details that describe a building for permits and construction. Our construction documentation services prepare these sets from sketches, PDFs or markups.
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