# Number
A Amperes
A Air or Compressed Air
A/C Air conditioner
AB Anchor Bolt
ABV Above
AC Alternating Current
ACD Automatic Control Damper
ACI American Concrete Institute
ACOUS Acoustical
AD Access Door
ADA Americans with Disabilities Act of 1992
ADDL Additional
ADH Adhesive
ADJ Adjustable
AF Air Foil
AFCI Arc Fault Circuit Interrupter
AFF Above Finished Floor
AFG Above Finished Grade
AGG Aggregate
AHJ Authority Having Jurisdiction
AHU Air Handling Unit
AIA American Institute of Architects
AIC Ampere Interrupting Capacity
AISC American Institute of Steel Construction
AISI American Iron and Steel Institute
AL & ALUM Aluminum
ALT Alternate
AMP Ampere
ANC Anchorage
ANOD Anodized
ANSI American National Standards Institute
AP Access Panel
APD Air Pressure Drop
APT Apartment
APX Approximate
ARCH Architect
AS Air Stream
ASCE American Society of Civil Engineers
ASD Allowable Stress Design
ASME American Society of Mech Engineers
ASPH Asphalt
ASTM American Society for Testing & Material
ATC Automatic Temperature Control
ATM Atmosphere
ATS Automatic Transfer Switch
AUTO Automatic
AVE Avenue
AVR Average
AWG American Wire Gauge
AWN Awning
AWS American Welding Society
B Bottom
B/O By Others
BD Board
BDD Back-Draft Damper
BHP Brake Horsepower
BI Backwards Inclined
BITUM Bituminous
BLDG Building
BLDV Boulevard
BLK Block
BLKG Blocking
BLW Below
BM Beam
BO Bottom Of or Building Official
BOD Bottom of Duct
BOF Bottom of Footing
BOF Bottom of Foundation
BOM Bill of Material
BOT Bottom
BOW Bottom of Wall
BP or B/P Blueprint
BR Bedroom
BRG Bearing
BRKT Bracket
BSMT Basement
BT Bath Tub
BTU British Thermal Units
BTUH BTU per Hour
BTW Between
BUR Built-Up Roofing
BV Butterfly Valve
BVL Beveled
BWV Back Water Valve
C Conduit
C/B Circuit Breaker
CAB Cabinet
CAD Computer-Aided Drafting
CALC Calculation
CAS Casement
CATV Cable Television
CB Critical Branch or Catch Basin
CBM Certified Ballast Manufacturer
CC Center to Center
CCT, CIR, CKT Circuit
CCTV Closed Circuit Television
CD Candela or Cabinet Door
CENT Center or Centrifugal
CF Cubic Feet
CFH Cubic Feet per Hour
CFM Cubic Feet per Minute
CFS Cubic Feet per Second
CG Corner Guard
CH Chilled or Chiller
CHW Chilled Water
CHWR Chilled Water Return
CHWS Chilled Water Supply
CI Cast Iron
CIP Cast-In-Place
CIR Circuit (also: CCT, CKT) or Circle
CJ or CJT Control Joint
CL Centerline or Closet
CLDI Cement Lined Ductile Iron
CLF Current Limiting Fuse
CLG Ceiling
CLK Caulking
CLR Clear
CMU Concrete Masonry Unit
CO Carbon Monoxide or Cleanout
COL Column
CONC Concrete
CONN Connection
CONST JT Construction Joint
CONST Construction
CONT Continuous
CONTR Contract
COORD Coordinate
CORR Corrugated
CP Chrome Plated
CPT Carpet or Control Power Transformer
CRES Corrosion-Resistant Steel
CRPT Carpet
CRSI Concrete Reinforcing Steel Institute
CSINK Countersink
CT Current Transformer
CT Cooling Tower or Ceramic Tile
CTBD Cooling Tower Blow Down
CTE Connect to Existing
CTYD Courtyard
CU Copper
CU. FT. Cubic Feet
CU. YD. Cubic Yard
CUFT Cubic Foot
CUH Cabinet Unit Heater
CUYD Cubic Yard
CW Cold Water
CWR Cold Water Return
CWR Condenser Water Return
CWS Cold Water Supply
CWS Condenser Water Supply
D Drain & Nail Size
dB Decibel
DB Dry Bulb (Temperature)
DC Direct Current
DCVA Double Check Valve Assembly
DDC Direct Digital Control
DEG Degree
DEPR Depression
DET Detail
DF Drinking Fountain
DH Double Hung
DIA Diameter
Dim Dimension
DIR Direction
DIV Division
DL Development Length
DN Down
DP Damp-proofing; Distribution Panel
DP Differential Pressure or Dampproofing
DR Door
DRWR Drawer
DS Downspout
DT Drain Tile
DTL Detail
DW Dishwasher
DWG Drawing
DWLS Dowels
E East
EA Each or Exhaust Air
EAHU Exhaust Air Handling Unit
EAT Entering Air Temperature
EB Equipment Branch
EC Elec Code or Elec Contractor
ED Edge Distance
EE Each End
EF Each Face or Exhaust Fan
EJ Expansion Joint
EL or ELEV Elevation
ELEV Elevator
EM or EMER Emergency
EMS Energy Management System
EMT Electrical Metallic Tubing
EP Emergency Power
EPO Emergency Power Off
EQ Equal
EQP Equipment
ES Each Side
ESP External Static Pressure
ET Expansion Tank
EUH Electrical Unit Heater
EW Each Way
EWC Electric Water Cooler
EWT Entering Water Temperature
EXCV or EXC Excavate
EXH or EX Exhaust
EXIST Existing
EXP Bolt Expansion Bolt
EXP JT Expansion Joint
EXP Expansion
EXT External or Exterior
F Fuse or Fahrenheit
FA Free Area or Fire Alarm
FAA Fire Alarm Annunciator
FACP Fire Alarm Control Panel
FAO Finish All Over
FBD Fiberboard
FBO Furnished by Others
FC Flexible Connection
FCB Fiber Cement Board
FCO Floor Cleanout
FCU Fan Coil Unit
FD Floor Drain, Fire Damper, or Fire Depart
FE Fire Extinguisher
FEC Fire Extinguisher Cabinet
FF Far Face
FFE Finished Floor Elevation
FFL Finished Floor Level
FGL Fiberglass
FHV Fire Hose Valve
FIN Finish
FL Floor Level
FLA Full Load Amperes
FLEX Flexible
FLOR Fluorescent
FLR Floor
FLRDR Floor Drain
FLSH Flashing
FMC Flexible Metal Conduit
FND Foundation
FOC Face of Concrete
FOF Face of Finish
FOM Face of Masonry
FOS Face of Studs
FOW Face of Wall
FP Fire Protection
FPL Fireplace
FPM Feet per Minute
FPS Feet per Second
FPWH Freeze-Proof Wall Hydrant
FRM Framing
FRP Fiberglass Reinforced Plastic
FRPF Fireproof
FS Far Side or Flow Switch
FT Foot or Feet
FTG Fitting or Footing
FTR Fin Tube Radiation
FUR Furred
FV Flush Valve
G Ground or Gas
G.T. Glazed Tile
GA Gauge
GAL Gallon
GALV Galvanized
GB Grade Beam
GC General Contractor
GCO Ground Clean-Out
GFCI, GFI Ground Fault Circuit Interrupter
GFU Glycol Feed Unit
GI Grease Interceptor or Galvanized Iron
GL Glass, Glazing
GLB Glue Laminated Beam
GLBK Glass Block
GND Ground
GP Gusset Plate
GPF Gallons per Flush
GPH Gallons per Hour
GPM Gallons per Minute
GR or GRD Grade
GRMC Galvanized Rigid Metal Conduit
GT Grout
GWB Gypsum Wall Board
Gyp. Gypsum
HB Hose Bib
HC Handicapped or Hollow Core or Head
HDCP Handicapped
HDPE High-Density Polyethylene
HDR Header
HEF Horizontal Each Face
HIF Horizontal Inside Face
HOA Hand-Off-Automatic Switch
HOF Horizontal Outside Face
HOR Horizontal
HP Horsepower or High Point
HR Hour
HRS Hot Rolled Steel
HRU Heat Recovery Unit
HS High Strength
HT Height
HTG Heating
HV High Voltage
HVAC Heating, Ventilation, Air Conditioning
HW Hot Water
HWD Hardware
HWR Hot Water Return
HWS Hot Water Supply
HZ Hertz (Cycles per Second)
IAW In Accordance With
ICBO International Conference of BO
ID Inner Diameter
IE Invert Elevation
IEEE Institute of Electrical & Electronics Engineers
IG Isolated Ground
IMC Intermediate Metal Conduit
In Inch
INCL Include
INS Insulate
Insul Insulation
INT Interlock or Interior
INV Invert
ISO International Organization for Standards
IW Indirect Waste
J-Box Junction Box
Jct Junction
JNT or JT Joint
Jst Joist
K Kip (1000 Pounds)
KCMIL Thousand Circular Mils
KD Kiln Dried
KIT Kitchen
KVA Kilovolt-Amperes
KVAR Kilovolt-Amperes Reactive
KW Kilowatt
L Length
LAM Laminated
LAT Leaving Air Temperature
LAV Lavatory
LB Pound
LD Linear Diffuser
LDD Limited Dimension Drawing
LF Linear Feet
LFMC Liquid Tight Flexible Metal Conduit
LFT Linear Feet
LH Left Hand
LL Live load
LLV Long Leg Vertical
LM List of Materials
LOA Length Overall
LP Low Point
LPS Low-Pressure Steam
LRA Lock Rotor Amps or Locked Rotor Amps
LRFD Load & Resistance Factor Design
LT Light
LTG Lighting
LUVR or LVR Louver
LVDR Louvered Door
LVG Leaving
LVL Laminated Veneer Lumber
LW Light Weight
LWC Light Weight Concrete
LWT Leaving Water Temperature
MAS Masonry
MAX Maximum
MBH 1000 BTUH
MBR Member
MBW Measurement Between Wires
MC Metal Clad Cable or Medicine Cabinet
MCA Minimum Circuit Amps
MCB Main Circuit Breaker
MCC Motor Control Center
MCP Motor Circuit Protection
MD Motorized Damper
MDF Medium Density Fiberboard
MDO Medium Density Overlay
MECH Mechanical
MED Medium
MFG Manufacturing
MFR Manufacturer
MH Manhole
MI Mineral Insulated
MIN Minimum
MIR Mirror
MISC Miscellaneous
MLB Micro Laminate Beam
MLD Molding
MLO Main Lugs Only
MMB Membrane
MO Masonry Opening
MOD Module
MOW Measurement Over Wires
MSB Mop Service Basin
Mtl Material
MTL Metal
MU Make-Up Water
MUA Make-Up Air
MW Megawatt
MWK Millwork
N North
NC Noise Criteria or Normally Closed
NEC National Electrical Code
NEMA National Electrical Manufacturers Assoc
NF Near Face
NFPA National Fire Protection Association
NIC Not in Contract
NL Night Light
NO Normally Open or Number
NOM Nominal
NTS Not To Scale
NWC Normal Weight Concrete
O Non-Operable Window
OA Outside Air
OAI Outside Air Intake
OAL Overall length
OBS Obscure
OC On Center
OD Outside Diameter
ODP Open Drip Proof
OED Open-End Drain
OP Opaque
OPNG or OPG Opening
OSB Orientated Strand Board
OV Outlet Velocity
P Pole
PB Push Button or Panic Button or Pull Box
PBD Particle Board
PBF Prefabricated
PC Pile Cap
PCC Precast Concrete
PCF Pounds Per Cubic Foot
PCS Pieces
PD Pressure Drop
PER Perforated
PH Phase or Toilet Paper Hanger
PIV Post Indicator Valve
PL Plaster or Property Line or Plate
PLAM Plastic Laminate
PLAS Plaster
PLBG Plumbing
PLF Pounds Per Linear Foot
PLT Plate
PLYWD Plywood
PMT Painted
PNL Panel
PRF Preformed
PRT Partition
PRV Pressure Reducing Valve
PSF Pounds Per Square Foot
PSI Pounds Per Square Inch
PSIA Pounds Per Square Inch – Absolute
PSID Pounds Per Square Inch – Differential
PSIG Pounds Per Square Inch – Gauge
PT Point or Potential Transformer
PT Pressure Treated
PTD Painted
PVC Polyvinyl Chloride
PVMT Pavement
PWR Power
QT Quarry Tile
QTY Quantity
R & RAD Radius
R&S Rod & Shelf
R Riser
RA Return Air
RC Reinforced Concrete
RD Roof Drain or Rod
RDL Roof Drain leader
RE Right End or Reinforced
REBAR Reinforcing Bar
REF Reference
REFR Ref
REG Register
REINF Reinforced
REQ & REQD Required
RET Return
RETG Retaining
REV Revision
RFG Roofing
RFL Reflect
RH Right Hand or Relative Humidity
RLA Running Load Amps
RLF Relief
RM Room
RMC Rigid Metal Conduit
RMS Root Mean Squared
RNC Rigid Non-Metallic Conduit
RO Rough Opening
RPBP Reduced Pressure Backflow Preventer
RPM Revolutions per Minute
RTS Remote Test Station
RTU Roof Top Unit
S South
SA Shock Absorber or Supply Air
San Sanitary
SC Sharp Corners or Shear Connector
SC Solid Core
SCH Schedule
SCN Screen
SCT Saturated Condensing Temperature
SD Sanitary Drain
SD Smoke Detector or Smoke Damper
SDI Steel Deck Institute
SE Smoke Exhaust
SEB Service End Line Box or Service Elec Box
SECT Section
SEN Sensible
SF Step Footing or Square Foot
SFD Combination Smoke / Fire Damper
SGD Sliding Glass Door
SH or SHWR Shower
SH Shelf, Shelving
SHC Sensible Heat Capacity
SHT Sheet
SHTH, Sht’g Sheathing
SIM Similar
SK Sink
SKL Skylight
SL Splice Length
SLB Slab
SLD Slider(ing)
SLV Short Leg Vertical
SOG Slab on Grade
SP Spare or Static Pressure
SPEC Specification
Specs Specifications
SPK Sprinkler
SQ Square
SQ. FT. Square Feet
SQ. IN. Square Inches
SS Soil Stack or Stainless Steel
ST Shunt Trip
STD Standard
STIFF Stiffener
STL Steel
STR Structural
STV Stove
SUP Support or Supply
SW Switch or Shear Wall
SY Square Yard
SYM Symmetrical
SYS System
T Top or Temperature or Thermostat
T&B Top & Bottom
T&G Tongue & Groove
T/O Top of
T Tread
TB Towel Bar
TEFC Totally Enclosed Fan Cooled
TEL & TELE Telephone
TEMP Temperature or Tempered
TGB Telecommunications Grounding Busbar
THK Thick or Thickness
THRD Threaded
TK Tight Knot
TLT Toilet
TMCB Thermal Magnetic Circuit Breaker
TO Top of
TOB Top of Beam
TOC Top of Curb or Top of Concrete
TOF Top of Footing/Foundation
TOJ Top of Joist
TOM Top of Masonry
TON 12,000 BTUH (Cooling Capacity)
TOS Top of Steel
TOW Top of Wall
TS Tamper Switch or Tubular Steel
TSP Total Static Pressure
TSTAT Thermostat
TW Tempered Water
TYP Typical
U Urinal
UC Undercut (Door)
UG Underground
UL Underwriters Laboratory
UNF Unfinished
UNO Unless Noted Otherwise
US Underside
V Volts or Vent
VA Voltage or Volt-Ampere
VAR Varnish
VAV Variable Air Volume
VB Vacuum Breaker or Vapor Barrier
VD Volume Damper
VEF Vertical Each Face
VEL Velocity
VERT Vertical
VFD Variable Frequency Drive
VG Vertical Grain
VIF Vertical Inside Face or Verify in Field
VIN Vinyl Sheet
VOF Vertical Outside Face
VRN Veneer
VS Vent Stack
VT Voltage Transformer
VTR Vent Through Roof
W Watt or Wire or Waste
W/ With or West
W/O Without
WB Wet Bulb Temperature
WC Water Column or Water Closet (Toilet)
WD Wood
WG Water Gauge
WH Wall Hydrant or Water Heater
WI Wrought Iron
WIC Walk-in Closet
WIN & Wdw Window
WL Water Level or Wall
WP Weather Proof or Working Point
WPD Water Pressure Drop
WR Weather Resistant
WRB Weather Resistive Barrier
WS Weatherstripping or Water Stop
WS Waste Stack
Wt Weight
WTD Water Temperature Difference
Wtr. Htr. Water Heater
WWF Welded Wire Fabric
WWM Welded Wire Mesh
X Operable Window Section
XFMR Transformer
Φ Phase Ω Ohm