What Is a ROM Estimate?
A ROM (Rough Order of Magnitude) estimate is an early-stage estimate used to establish preliminary project budgets before design documents are fully developed. ROM estimates are typically based on conceptual information, historical data, benchmarking, and high-level assumptions.
Contractors and owners often use ROM estimates during feasibility studies, conceptual design, and early project planning to determine whether a project is financially viable.
What Is a Detailed Estimate?
A detailed estimate is developed once drawings, specifications, and scope definitions are more complete. This type of estimate includes detailed quantity takeoffs, labor analysis, subcontractor pricing, material costs, equipment, indirect costs, escalation, and contingency considerations.
Detailed estimates provide a much higher level of accuracy and are commonly used for bidding, GMP development, procurement planning, and project execution.
Key Differences Between ROM and Detailed Estimates
ROM estimates prioritize speed and budgeting guidance, while detailed estimates prioritize precision and execution planning.
ROM estimates:
- Faster turnaround
- Higher contingency
- Limited design information
- Used for budgeting and feasibility
Detailed estimates:
- Quantity driven
- Trade specific pricing
- Lower contingency
- Used for procurement and construction execution
When Should Contractors Use Each One?
ROM estimates are ideal during:
- Early client discussions
- Concept validation
- Budget feasibility
- Initial funding reviews
Detailed estimates are best for:
- Bid submissions
- GMP validation
- Procurement
- Schedule coordination
- Construction execution
How TBT Estimating Services Can Help
TBT Estimating Services provides both conceptual ROM estimating and detailed preconstruction estimating support tailored to contractors nationwide.
Our services include:
- Quantity takeoffs
- Quantity surveying
- ROM & should-cost estimating
- Bid leveling & ITB management
- Change order management
- Preconstruction support
We handle the numbers so you can build the future.