Suele haber una leyenda en cada plano pero por si acaso, aquí tienes una lista de las abreviaciones más comunes en plantas, alzados, secciones y detalles constructivos.


AAB   Air Admittance Valve
AB   Air Brick
AC   Air Conditioning
AOV   Automatic Opening Ventilation
B   Boiler
BD   Board
BS   British Standards
CC   Centre to Centre
CCTV   Closed-Circuit Television
CFHS   Cold Formed Hollow Section
CHS   Circular Hollow Section (perfil tubular)
CL   Centre Line
CLT   Cross-Laminated Timber
CPB   Cement Particle Board (known as sheathing board)
D   Diametre
Dim.   Dimension
DPC   Damp Proof Course
DPM   Damp Proof Membrane
DPS   Damp Proof Spray
DR   Dry Riser
DW   Dishwasher
E   Edge
EPS   Expanded Polystyrene
F   Fridge
FD   Fire Door
FFL   Finish Floor Level
FGL   Finish Ground Level
FSG   Future Shower Gully
G   Gully (sumidero)
GA   General Arragement (plano general)
GL   Grid Line (or Ground Level)
GRP   Glass-Reinforced Polyester (Fibreglass)
H   Height
HRV   Heat Recovery Ventilation
MEV   Mechanical Extract Ventilation
MH   Manhole (alcantarilla)
MJ   Movement Joint
MVHR   Mechanical Vent with Heat Recovery
M&E   Mechanical Engineer
No.   Number
NTS   Not To Scale
OSB   Oriented Strand Board
OV   Opening for Ventilation
PC   Pre-Cast (concrete)
PIR   Polyisocyanurate Board (porexpan extruido)
PUR   Polyurethane Board (porexpan expandido)
PV   Periscope Ventilator
QS   Quantity Surveyor
RC   Reinforced Concrete 
RHS   Rectangular Hollow Section (including square ones)
RSA   Rolled Steel Angle
RWO   Rain Water Outlet
RWP   Rain Water Pipe
SE   Structural Engineer
SFL   Structural Floor Level
SFS   Steel Framing System
SHS   Square Hollow Section 
SO   Structural Opening
SOA   Schedule Of Accommodation
SOL   Setting Out Line
SOP   Setting Out Point
SQ   Square
SS   Stub Stack / Stainless Steel
SSL   Structural Slab Level
STD   Standard
STR   Structure
SV   Safety Valve
SVP   Soil Vent Pipe
TBC   To Be Confirmed
THK   Thick
TOB   Top Of Beam
TOC   Top Of Concrete
TOP   Top Of Parapet 
TOS   Top Of Structure
TOW   Top Of Wall
TPO   Tree Preservation Order
U/S   Underside
UB   Universal Beam (IPE)
UC   Universal Column (HEB)
UNO   Unless Noted Otherwise
VCL   Vapour Control Layer
VP   Vent Pipe
W   Width
WBP   Weather and Boil Proof (plywood)
WL   Water Level
WM   Washing Machine
WPM   Water Proof Membrane