The detailed estimate ( or contractor's estimate) is based on complete engineering drawings, specifications, and site surveys. Fixed and firm prices against complete specifications are obtained from vendors for all equipment. All Bills of Material are complete and accurate and are priced by erection contractors. In spite of this level of detail the probable error in in the estimate is still ±5%.
Earthworks
Civils
Architectural Buildings
Structural Steelwork
Equipment/Machinery
Piping/Fittings/Valves
Electrics
Instrumentation
Painting
Insulation
Field Indirects
Engineering Costs (Home Office and Site)
Escalation
Contingency
Client's Costs
The estimating team requires the following general and engineering information:
Copies of all enquiry documents
Finalised P&IDs for process, utilities and offsite utilities
Detailed Plot Plans
Detailed engineering specifications
Detailed planning schedules for engineering, plannning, procurement, construction
Equipment data sheets
Detailed engineering data for all disciplines (civil/ piping/electrics/etc.)