How to Read Construction Plans

Understanding blueprints is essential for accurate takeoffs and successful projects.

Anatomy of a Plan Set

A complete set of construction documents typically includes:

Cover Sheet

• Project name and address
• Owner and architect info
• Drawing index
• General notes
• Code information

Site Plans (C Sheets)

• Property boundaries
• Building location
• Parking and drives
• Utilities
• Grading and drainage

Architectural Plans (A Sheets)

• Floor plans
• Elevations
• Building sections
• Details
• Door/window schedules

Structural Plans (S Sheets)

• Foundation plans
• Framing plans
• Structural details
• Connection details

MEP Plans

• M - Mechanical (HVAC)
• E - Electrical
• P - Plumbing

Understanding Scale

What is Scale?

Scale shows the relationship between the drawing and reality.

1/4" = 1'-0" means:

• 1/4 inch on paper = 1 foot in real life
• A 10' wall measures 2.5" on paper

Common Scales

Reading a Scale Ruler

Architect's scale rulers have multiple scales. Find the correct scale and read directly - no math needed.

Plan Symbols

Door Symbols

┌─────┐      Single door (90° swing shown)
│     │
│   ╱ │
│  ╱  │
└─────┘

┌─────┐      Double door
│ ╲ ╱ │
│  X  │
│ ╱ ╲ │
└─────┘

├═════┤      Sliding door

Window Symbols

═══════      Standard window

══╪══╪══     Window with mullions

▓▓▓▓▓▓▓      Window in elevation

Wall Types

Electrical Symbols

Plumbing Symbols

Reading Dimensions

Dimension Lines

     3'-6"
←─────────→   Dimension with arrows and text

Running Dimensions

Show cumulative distances from a reference point:

┃  2'-0"  ┃  5'-6"  ┃  9'-2"  ┃

Each number is measured from the starting point, not incremental.

Reference Points

• Column lines - Grid labeled A, B, C... and 1, 2, 3...
• Centerlines - CL marked
• Face of stud - F.O.S.
• Face of concrete - F.O.C.

Floor Plans

What They Show

• Room layout and sizes
• Wall locations
• Door and window locations
• Built-in items (cabinets, fixtures)
• Dimensions
• Room names and numbers

What They Don't Show

• Ceiling heights (see sections)
• Material finishes (see schedules)
• Structural info (see structural plans)
• MEP locations (see MEP plans)

Reading Room Sizes

Rooms typically dimensioned to:

• Face of stud (most common)
• Centerline of wall
• Face of finish

Check notes or conventions used.

Elevations

What They Show

• Exterior appearance
• Vertical heights
• Window/door heights
• Roof slopes
• Material indications

Height References

• T.O.F. - Top of foundation
• F.F. - Finished floor
• T.O.W. - Top of wall
• T.O.P. - Top of parapet

Sections

What They Show

• "Cut through" view of building
• Wall construction
• Floor-to-ceiling heights
• Foundation details
• Roof construction

Section Markers

On floor plans, a section cut is shown as:

     A
    ←──
    ──→
     A3

• Top: Section name
• Bottom: Sheet where section is drawn
• Arrow: Direction you're looking

Schedules

Tables that list specifications:

Door Schedule

Window Schedule

Finish Schedule

Abbreviations

Common abbreviations you'll see:

Tips for Reading Plans

Before You Start

1. Read the cover sheet and general notes
2. Understand the scale on each sheet
3. Review the drawing index
4. Note revision dates and clouds

While Reading

1. Orient yourself (north arrow)
2. Use column grid for reference
3. Cross-reference related drawings
4. Check schedules for details
5. Note anything unclear for RFI

Common Mistakes

• Assuming scale without verifying
• Missing addenda or revisions
• Not reading specifications
• Ignoring general notes
• Not asking questions

Practice Tips

Best way to learn:

1. Get plans for a completed project
2. Walk the building with plans in hand
3. Match what you see to drawings
4. Note how things were drawn vs. built

Next Steps

• Takeoff Basics - Measure from plans
• Scale Calibration - Set up digital takeoff
• AI Detection - Auto-detect elements