Construction industry acronyms - O
This article presents a list of construction industry acronyms beginning with 'O'.
For other letters click on the list below:
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
[edit] O
02 - Oxygen
O&M - Operations and Maintenance (See Building Owner's Manual)
O/A - On or About
OA - On or About
OA - Optimised Alternative
OAD - Outside Access Device
OAPF - Opportunity Area Planning Framework
OBC - Outline Business Case
OBR - Office For Budget Responsibility
Obs - Obsolete/Obsolescent
OBS - Organisation Breakdown Structure
OBS - Office for Building Safety (Northern Ireland)
OBST - Operational Business Systems Team
OC - On Centre
OC - Open Crossing
OCDEA - On Construction Domestic Energy Assessor
OCF - Open Connectivity Foundation
OCIP - Owner-controlled insurance programme
OCR - Opportunity Cost Rent
OCS - Overhead Catenary System
OCT - Overseas Countries and Territories
OD - Ordnance Datum
OD - Original Datum
OD - Outside Diameter
ODA - Olympic Delivery Authority
ODM - Original Design Manufacturer
ODP - Ozone Depletion Potential
ODS - Ozone Delpleting Substances.
ODYM - Open Dynamic Material Systems Model
OECD - Organisation for Economic Cooperation and Development
OEE - Overall Equipment Effectiveness
OEL - Occupational Exposure Limit
OELS - Organic Entry Level Stewardship
OEM - Original Equipment Manufacturer
OES - Occupational Exposure Standard
OES - Optical Emission Spectrometry
OF - Overflow
OFGEM - Office of Gas and Electricity Markets
OFL - Over-Flow alarm
OFS - Oil Fired Appliance Standard
Ofsted - Office For Standards In Education
OFWAT - Office of Water Services
OfWAT - The Water Services Regulation Authority
OGC - Office of Government Commerce (no longer in existence)
OGC - Open Geospatial Consortium
OGD - Other Government Departments
OGSF - Overall Gross Square Footage
OH - Occupational Health
OH - Over Head
OHAC - Occupational Health Advisory Committee
OHP - Overhead Projector
OIC - Open Connectivity Foundation
OIL - Open Items List
OIL - Outstanding Items List
ONR - Office for Nuclear Regulation
OIOO - One In One Out
OIR - Oganisational Information Requirements
OITO - One In Two Out
OJEU - Official Journal of the European Union
OLA - Occupiers' Liability Act
OLB - Timber Origin and Legality (Origine et Légalité des Bois)
OLC - Open Level Crossing
OLE - Object Linking and Embedding
OM - Operating & Maintenance (Manual)
OM - Operations Manager
OM - Organic Matter
OML - Ordinary Maternity Leave
OMM / O&MM Operation & Maintenance Manual
OMP - Odour Management Plan
ONR - Office For Nuclear Regulation
ONS - Office For National Statistics
OP - Orifice Plate
OPA - Output and Performance Analysis
OPAS - Operational Property Asset System
OPC – Ordinary Portland Cement
OPEX - Operational Expenditure
OPIP - Operational Process Improvement Project
OPM - Output and Performance Measures
OPO - One Person Operated
OPPI - Owners' Protective Professional Insurance
OPR - Owner's Project Requirements
OPSS - Office for Product Safety and Standards
ORC - Organic Rankine Cycle
ORR - Office of Rail and Road (was Office of Rail Regulation)
ORR - Office Of Rail Regulation
OS - Ordnance Survey
OSAT - On-Site Assessment and Training
OSB - Oriented Strand Board
OSC - Offsite Construction
OSC - Operational Safety Case
OSD - Over Site Development
OSF - On-the-job, social, formal
OSHA - Occupational Safety and Health Administration
OSI - Open Systems Interconnection (model)
OSM - Offsite Manufacturing
OSP - Offsite Production
OSRPA - Offices Shops and Railway Premises Act
OSS - Open Spaces Society
OTA - Owner Tenant Agreement
OTL - Object Type Library
OTS - Office of Tax Simplification
OUSD - Open Universal Scene Description
OV - Oven
OWIC - The Offshore Wind Industry Council
OWMIS - Offshore Wind Manufacturing Investment Scheme
OZ - Outer Zone
Featured articles
Building Safety Wiki Interviews
Chief executive of the British Woodworking Federation.
Planning condition discharge in England and Wales
A brief explanation from a building compliance expert, with further links.
Overheating guidance and tools for building designers
Guidance for dealing with element of building fabric control that have increasing importance.
Shading for housing, a design guide
From the Good Homes Alliance and British Blind and Shutter Association.
UK Standard Skills Classification (SSC)
A shared framework for describing skills needs.
Social media ban consultation comes to close
CIOB urges UK Government to consider social media’s role in careers guidance in ban debate.
The latest of eight Skills England apprenticeship units
The addition of battery manufacturing welcomed by ECA with a warning about the risks of fast-tracked apprenticeship units.
Building Control Independent Panel final report
A precis of a key report led by Dame Hackitt with full recommendations and link to the government response.
Building Safety recap April, 2026
A short and longer run-through of the month, with links to further information and sources.
CIAT May 2026 briefing.
From medieval scribes to modern word art.
ECA welcomes crackdown on late payment and push for clean energy, whilst CIOB seek fixed cladding removal timeframes.
Cyber Security in the Built Environment
Protecting projects, data, and digital assets: A CIOB Academy TIS.
Managing competence in the built environment
ITFG publishes new industry guide on how to meet the ICC principles.