Quantity Surveying: Complete Professional Course

What is Quantity Surveying?

Quantity Surveying (QS) is the art and science of extracting material quantities and work items from engineering drawings and specifications. It forms the foundation for project pricing, bid preparation, and cost control throughout construction.

1.1 The Three Pillars of QS

1. Measurement - Accurately quantifying work from drawings
2. Valuation - Pricing measured work
3. Cost Management - Controlling project costs

1.2 Why QS is Critical

1.3 QS vs. Estimating

Often confused, but different:

• Quantity Surveying: Measuring quantities from drawings (WHAT and HOW MUCH)
• Estimating: Applying rates to quantities to get costs (HOW MUCH MONEY)

QS Duties Throughout Project Lifecycle

2.1 Pre-Contract Phase

2.2 Post-Contract Phase

2.3 Types of QS Roles

• Client-side QS: Protect owner's interests, cost control
• Contractor QS: Maximize contractor's entitlements, commercial management
• Consultant QS: Independent measurement and valuation
• PQS (Principal QS): Lead QS on major projects

Standard Methods of Measurement

3.1 Major Measurement Standards

3.2 Units of Measurement

3.3 Measurement Rules Examples

Extracting Quantities from Drawings

4.1 Take-off Process

1. Receive Drawings: Ensure completeness, check revision dates
2. Study Project: Understand scope, specifications, details
3. Plan Take-off: Decide order, grouping, methodology
4. Measure: Extract dimensions from drawings
5. Calculate: Apply formulas, compute quantities
6. Compile: Organize in standard format
7. Check: Verify calculations, cross-reference

4.2 Take-off Methods

4.3 Dimension Paper Layout

┌─────────────────────────────────────────────────────────────────────┐
│ DIMENSION PAPER                            Sheet: 1    Project: Villa │
├──────┬────────┬────────┬────────┬───────────────────────────────────┤
│ Times│   Dim  │   Dim  │   Dim  │        Description                │
├──────┼────────┼────────┼────────┼───────────────────────────────────┤
│   4  │  6.00  │  0.60  │  0.60  │ RC Foundations Type F1            │
│      │        │        │        │ Concrete grade C30                │
│      │        │  =     │  8.64  │ m³                                │
├──────┼────────┼────────┼────────┼───────────────────────────────────┤
│   2  │  8.00  │  0.60  │  0.60  │ RC Foundations Type F2            │
│      │        │        │        │ Concrete grade C30                │
│      │        │  =     │  5.76  │ m³                                │
├──────┴────────┴────────┴────────┴───────────────────────────────────┤
│                              Total Foundations Concrete = 14.40 m³   │
└─────────────────────────────────────────────────────────────────────┘

4.4 Common Formulas

4.5 Rebar Unit Weights

Creating Professional BOQ Documents

5.1 BOQ Structure

1. Preliminaries: General conditions, temporary works, insurance
2. Preambles: Measurement rules, workmanship standards
3. Measured Works: Main quantity items by trade/element
4. Provisional Items: Unknown/undefined scope
5. Prime Cost Sums: Pre-defined amounts for specific work
6. Contingency: Risk allowance (typically 5-10%)
7. Summary: Trade/section totals

5.2 BOQ Item Components

5.3 Sample BOQ Extract

BILL NO. 3: CONCRETE WORKS
─────────────────────────────────────────────────────────────────────────────
Item │ Description                                          │ Unit │   Qty  │  Rate  │  Amount
─────┼──────────────────────────────────────────────────────┼──────┼────────┼────────┼──────────
3.01 │ FOUNDATIONS                                          │      │        │        │
     │                                                      │      │        │        │
3.01.│ Blinding concrete C10 50mm thick                    │  m²  │  85.00 │        │
 01  │ under foundations                                    │      │        │        │
     │                                                      │      │        │        │
3.01.│ Reinforced concrete grade C30/37                    │  m³  │ 145.50 │        │
 02  │ in isolated pad foundations, including               │      │        │        │
     │ placing and vibrating                                │      │        │        │
     │                                                      │      │        │        │
3.01.│ Formwork to edges of foundations                    │  m²  │  42.00 │        │
 03  │ plain vertical not exceeding 500mm high              │      │        │        │
     │                                                      │      │        │        │
3.01.│ High yield steel reinforcement bars                 │  kg  │7,850.00│        │
 04  │ to BS 4449, including cutting, bending               │      │        │        │
     │ and fixing                                           │      │        │        │
─────┴──────────────────────────────────────────────────────┴──────┴────────┴────────┴──────────
                                          ELEMENT TOTAL TO SUMMARY:

5.4 BOQ Preparation Best Practices

• ✅ Use consistent numbering system throughout
• ✅ Description must be complete and unambiguous
• ✅ Reference specifications and drawing numbers
• ✅ Group related items logically
• ✅ Provide sufficient decimal places (2 for most, 3 for small quantities)
• ✅ Include preambles explaining measurement conventions

Building Up Unit Rates

6.1 Rate Components

6.2 Rate Build-up Example

6.3 markup Benchmarks

Monthly Progress Payments

7.1 Interim Valuation Process

1. Schedule joint site measurement (QS + Contractor)
2. Measure completed permanent works
3. Assess value of materials on site
4. Value preliminaries (time-related items)
5. Include approved variations
6. Deduct retention (typically 5-10%)
7. Deduct previous payments
8. Issue payment certificate

7.2 Valuation Calculation

7.3 Retention Release

Retention is typically released in two stages:

• First Half (50%): At Practical/Substantial Completion
• Second Half (50%): At end of Defects Liability Period (typically 12 months)

Project Financial Close-out

8.1 Final Account Components

1. Measured Works: As-built final quantities
2. Variations: All approved changes
3. Claims: Approved contractor claims
4. Dayworks: Work done on cost-plus basis
5. Adjustments: PC sums, contingency, provisional
6. Deductions: Defects, back-charges, liquidated damages

8.2 Common Claim Types

8.3 Final Account Checklist

• ☐ All variations measured and agreed
• ☐ Outstanding claims resolved
• ☐ Defects made good or valued
• ☐ All PC sums and provisional items adjusted
• ☐ As-built drawings received
• ☐ Warranties and guarantees collected
• ☐ Retention release processed
• ☐ Final certificate issued