Construction Abbreviations Master List
Over 200 commonly used abbreviations found on construction drawings, organized by discipline. This searchable reference covers general drawing notations, structural, architectural, MEP, and fire protection abbreviations that appear across plan sets in commercial and residential projects.
General & Drawing Abbreviations
Universal abbreviations that appear across all disciplines and sheet types in a construction document set. These are the foundational shorthand notations every AEC professional should know.
ABV
Above
ADJ
Adjacent
ALT
Alternate
APPROX
Approximate
ARCH
Architectural
CL
Centerline
CLR
Clear
CONT
Continuous
DET
Detail
DIM
Dimension
DWG
Drawing
EA
Each
ELEV
Elevation
EQ
Equal
EXIST
Existing
EXT
Exterior
FIN
Finish
FT
Foot / Feet
GA
Gauge
HT
Height
HORIZ
Horizontal
IN
Inch
INT
Interior
MAX
Maximum
MIN
Minimum
MISC
Miscellaneous
NIC
Not in Contract
NTS
Not to Scale
O.C.
On Center
OPP
Opposite
QTY
Quantity
R
Radius
REF
Reference
REQ'D
Required
REV
Revision
SCHED
Schedule
SF
Square Feet
SIM
Similar
SPEC
Specification
STD
Standard
TYP
Typical
UNO
Unless Noted Otherwise
VERT
Vertical
VIF
Verify in Field
W/
With
W/O
Without
Structural Abbreviations
Abbreviations found on S-series (structural) sheets covering steel, concrete, masonry, and timber framing notations. These are essential for reading structural plans, details, and schedules.
BM
Beam
B.O.S.
Bottom of Steel
BRG
Bearing
CLM
Column
CMU
Concrete Masonry Unit
CONC
Concrete
DL
Dead Load
EJ
Expansion Joint
EW
Each Way
FOC
Face of Concrete
FOM
Face of Masonry
FOS
Face of Stud
FTG
Footing
GRD
Grade
HSS
Hollow Structural Section
LB
Pound
LL
Live Load
LVL
Laminated Veneer Lumber
NOM
Nominal
PC
Precast
PSF
Pounds per Square Foot
PSI
Pounds per Square Inch
PT
Post-Tensioned
REINF
Reinforcement / Reinforced
SL.O.S.
Slab on Steel
STL
Steel
T.O.C.
Top of Concrete
T.O.F.
Top of Footing
T.O.S.
Top of Steel
T.O.W.
Top of Wall
W
Wide Flange (Steel Shape)
WF
Wide Flange
WWF
Welded Wire Fabric
Architectural Abbreviations
Abbreviations commonly found on A-series (architectural) sheets including floor plans, reflected ceiling plans, elevations, wall sections, and finish schedules.
ACT
Acoustic Ceiling Tile
AFF
Above Finished Floor
AL
Aluminum
BD
Board
BLDG
Building
CAB
Cabinet
CLG
Ceiling
CMT
Ceramic Tile
CW
Curtain Wall
DR
Door
DS
Downspout
FF
Finished Floor
FFE
Finished Floor Elevation
FLR
Floor
GL
Glass / Glazing
GWB
Gypsum Wall Board
HM
Hollow Metal
INSUL
Insulation
LT
Light
MTL
Metal
OH
Overhead
PLY
Plywood
PTD
Painted
RCP
Reflected Ceiling Plan
RM
Room
SHT
Sheet
THK
Thick / Thickness
VCT
Vinyl Composition Tile
WD
Wood
WIN
Window
WP
Waterproof / Waterproofing
MEP Abbreviations
Mechanical, electrical, and plumbing abbreviations found on M, E, and P-series sheets. These cover HVAC equipment, electrical distribution, plumbing fixtures, and building systems.
AC
Air Conditioning
AHU
Air Handling Unit
AMP
Ampere
BFP
Backflow Preventer
BTU
British Thermal Unit
CFM
Cubic Feet per Minute
CHW
Chilled Water
CKT
Circuit
CO
Cleanout
CW
Cold Water
DB
Distribution Board
DF
Drinking Fountain
DISC
Disconnect
EF
Exhaust Fan
ELEC
Electrical
FCU
Fan Coil Unit
FD
Floor Drain
GFCI
Ground Fault Circuit Interrupter
GPM
Gallons per Minute
HP
Horsepower
HW
Hot Water
HVAC
Heating, Ventilation & Air Conditioning
KW
Kilowatt
LAV
Lavatory
MDP
Main Distribution Panel
PRV
Pressure Reducing Valve
RD
Roof Drain
RTU
Rooftop Unit
SD
Smoke Detector
SS
Stainless Steel
V
Volt
VAV
Variable Air Volume
VFD
Variable Frequency Drive
WC
Water Closet
WH
Water Heater
Fire Protection Abbreviations
Abbreviations specific to fire protection and life safety systems, found on FP-series and E-series sheets covering fire suppression, fire alarm, and detection equipment.
FACP
Fire Alarm Control Panel
FDC
Fire Department Connection
FE
Fire Extinguisher
FH
Fire Hydrant
FHC
Fire Hose Cabinet
FP
Fire Protection
FRC
Fire-Resistance Rated Construction
OS&Y
Outside Screw & Yoke (Valve)
PIV
Post Indicator Valve
SD
Smoke Detector
SPR
Sprinkler
Frequently Asked Questions
What does TYP mean on construction drawings?
TYP stands for Typical. When a dimension, note, or detail is marked TYP, it means the same condition applies to all similar instances throughout the drawing or project. For example, a column spacing dimension marked TYP indicates that every bay has the same spacing, even though it is only dimensioned once.
What is the difference between NIC and NTS?
NIC stands for Not in Contract, meaning a particular item or scope of work is shown on the drawings for reference but is not included in the current contract and will be provided by others. NTS stands for Not to Scale, indicating that a drawing or detail is not drawn at an accurate measurable scale and should not be scaled for dimensions.
What does O.C. mean in construction?
O.C. stands for On Center. It is a measurement method that specifies the spacing between repetitive elements (studs, joists, rebar, etc.) measured from the center of one element to the center of the next. For example, studs at 16" O.C. means 16 inches from the center of one stud to the center of the adjacent stud.
What does UNO stand for on construction documents?
UNO stands for Unless Noted Otherwise. It establishes a default condition that applies everywhere except where the drawings specifically indicate a different requirement. For example, a note reading "All GWB partitions are 5/8" type X, UNO" means gypsum board is 5/8" fire-rated throughout unless a specific partition is called out differently.
Related Resources
Construction Glossary
120+ construction industry terms and definitions for AEC professionals.
Drawing Symbols Guide
170+ symbols across architectural, structural, MEP, fire protection, and civil drawings.
Knowledge Base
Guides, references, symbols, abbreviations, and review checklists for AEC professionals.
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