Daily writing prompt
List five things you do for fun.
By Kavita Dehalwar
Construction estimates are prepared at different stages of a project depending on the level of information available. The main types are:
1. Order of Magnitude Estimate
This is the earliest and roughest estimate prepared.
Purpose
To get a broad idea of project cost
Used for initial decision-making
Basis
Past experience
Cost of similar projects
Very limited data
Accuracy
Use
Project idea stage
Go / No-go decision
2. Feasibility Estimate
Prepared to assess whether the project is financially viable.
Purpose
To evaluate economic feasibility
To compare alternatives
Basis
Approximate quantities
Area or unit rates
Preliminary layouts
Accuracy
Use
Feasibility studies
Investment appraisal
3. Preliminary Estimate
Prepared once the basic design and layout are available.
Purpose
To obtain administrative approval
To estimate project budget
Basis
Plinth area / floor area / cubic content method
Approximate specifications
Accuracy
Use
Budget sanction
Planning stage decisions
4. Substantive Estimate
Prepared after the design is finalized.
Purpose
To obtain technical sanction
To refine cost estimates
Basis
Detailed drawings
Updated specifications
Refined quantities
Accuracy
Use
Before tendering
Final cost assessment
5. Detailed Estimate
This is the most accurate and comprehensive estimate.
Purpose
For tendering and execution
To control project cost
Basis
Item-wise quantity take-off
Rate analysis using SOR
Detailed specifications
Accuracy
Use
Contract award
Construction and payment
Summary Table
Conclusion
As a project progresses, estimates become more detailed and accurate. Early estimates guide decisions, while detailed estimates ensure financial control and successful execution.
