Construction Estimates and Quantity Surveying - Concept Map
Construction Cost Estimation through Quantity Surveying
Related concepts
Quantity Take-Off (QTO)
Sub concepts
- Concrete Volume Calculation
- Reinforcing Steel Measurement
- Formwork Area Computation
- Earthwork Volumes
- Unit Mass Determination
Relationship to central
Foundation process that measures materials directly from drawings before pricing
Concrete Estimation
Sub concepts
- Volume Computation (L × W × H)
- Mix Design Classes (A, B, C)
- Cement Bags per m³
- Sand and Gravel Quantities
- Water-Cement Ratio
- Additives and Admixtures
Relationship to central
Major quantity category requiring volume and material proportioning calculations
Reinforcing Steel Estimation
Sub concepts
- Bar Diameter Classification
- Unit Mass Formula (0.006165d²)
- Total Bar Length Measurement
- Bar Bending Schedule
- Lap Splices and Anchorages
- Wire Ties and Accessories
Relationship to central
Critical quantity takeoff using unit mass formula and bar scheduling
Formwork Estimation
Sub concepts
- Contact Area Calculation
- Reuse and Recovery Rates
- Stripping Time Considerations
- Support Systems and Bracing
- Form Release Agents
Relationship to central
Measurement of contact surfaces and structural support requirements
Unit Cost Development
Sub concepts
- Material Costs
- Labor Costs and Productivity
- Equipment Costs and Rental
- Waste and Contingency Factors
- Market Price Fluctuations
- Supplier Quotations
Relationship to central
Process of assigning costs to each measured quantity item
Direct Cost Computation
Sub concepts
- Materials Subtotal
- Labor Subtotal
- Equipment Subtotal
- Waste Allowances
- Cost Breakdown by Trade
Relationship to central
Sum of all material, labor, and equipment costs for the project
Bid Price Development
Sub concepts
- Overhead Costs (OCM)
- Profit Margin
- Contingency Reserve
- Markup Percentage (15-25%)
- Value Added Tax (VAT)
- Bonds and Insurance
Relationship to central
Final selling price calculated by adding markups to direct costs
Estimating Standards and References
Sub concepts
- NSCP 2015 (Mix Proportions)
- ACI 318 (Reinforcement Requirements)
- AISC 360 (Steel Specifications)
- RA 544 (Philippine Construction Code)
- Industry Standard Productivity Rates
- Regional Material Pricing Data
Relationship to central
Technical codes and formulas governing quantity and cost calculations
Concept connections
- Quantity Take-Off ProcessConcrete EstimationQTO is the methodology; concrete estimation is one of its primary applications
- Quantity Take-Off ProcessReinforcing Steel EstimationQTO framework used to measure and document all steel bar quantities
- Quantity Take-Off ProcessFormwork EstimationQTO quantifies formwork contact areas from drawing geometry
- Concrete EstimationUnit Cost DevelopmentCalculated concrete volumes feed into unit pricing per cubic meter
- Reinforcing Steel EstimationUnit Cost DevelopmentSteel masses determined by QTO are multiplied by unit cost per kilogram
- Unit Cost DevelopmentDirect Cost ComputationUnit costs multiplied by quantities yield line costs summed into direct cost
- Direct Cost ComputationBid Price DevelopmentDirect cost is the foundation; markups applied to create bid price
- Bid Price DevelopmentTechnical Standards and ReferencesNSCP 2015, ACI 318, AISC 360 standards ensure accurate quantity and cost calculations
- Concrete EstimationTechnical Standards and ReferencesNSCP 2015 defines mix classes (A, B, C) and cement proportions per m³
- Reinforcing Steel EstimationTechnical Standards and ReferencesACI 318 and NSCP 2015 specify reinforcement requirements and unit mass calculations
- Formwork EstimationUnit Cost DevelopmentFormwork contact areas are priced per square meter
- EarthworkDirect Cost ComputationEarthwork volumes calculated in QTO; costs added to total direct cost
- Material CostsDirect Cost ComputationComponent of direct cost; includes concrete, steel, and other material expenses
- Labor CostsDirect Cost ComputationComponent of direct cost; based on productivity rates and wage schedules
- Equipment CostsDirect Cost ComputationComponent of direct cost; includes rental and operating expenses
- Overhead and ContingencyBid Price DevelopmentOCM markup applied to direct cost (10% typical)
- Profit MarginBid Price DevelopmentProfit percentage applied to direct cost to yield contractor compensation
- Waste and Contingency FactorsUnit Cost DevelopmentWaste allowances (5-10% for concrete, 2-5% for steel) increase quantities
- Bar Diameter ClassificationUnit Mass DeterminationDiameter d in mm is input to unit mass formula 0.006165d²
- Mix Design ClassesCement Bags per m³Class A (9 bags), Class B (7.5 bags), Class C (6 bags) - direct correspondence
Diagrams
Construction Estimates and Quantity Surveying - Complete Concept Map
Comprehensive mind map showing the hierarchical structure of construction estimation and quantity surveying, organized from raw quantity take-off through final bid pricing, with technical standards and references integrated throughout.
Quantity Take-Off Decision Tree and Calculation Sequence
Step-by-step flowchart depicting the quantity take-off process from drawing review through calculation of concrete volumes, steel masses, formwork areas, and earthwork quantities, with decision points for concrete mix classes and item type classification.
Bid Price Development and Cost Build-Up Process
Complete cost build-up flowchart showing the progression from quantities and unit costs through direct cost calculation, markup application (OCM and profit), tax consideration, and final bid price quotation. Illustrates how bid price is derived using the formula: Bid = Direct Cost × (1 + Markup).
Concrete Estimation Workflow with Mix Proportioning
Detailed workflow for concrete estimation showing geometry identification, volume calculation, NSCP 2015 mix class selection (A/B/C), cement bag determination, and aggregates computation with waste allowances.
Reinforcing Steel Mass Calculation Procedure
Step-by-step procedure for calculating reinforcing steel mass using the unit mass formula (0.006165d² kg/m), showing diameter-specific calculations, total length measurement, and waste allowance application per NSCP 2015 and ACI 318 standards.
Cost Estimate Development: From Quantities to Bid Price
Simplified overview of the cost build-up process showing the parallel paths for material, labor, and equipment costs converging into direct cost, then with markups and taxes applied to reach the final bid price.
Typical Bid Price Distribution and Markup Components
Pie chart illustrating the typical composition of a construction bid price, showing the proportion of direct cost (materials + labor + equipment), overhead and contingency, profit margin, and taxes/VAT. This visualization helps understand how markups are distributed within the final quotation.