A Bill of Quantities (BOQ) is a structured list of all the work items, materials, and services needed to complete a construction project—each with a quantity, unit, rate, and amount. Think of it as the project’s price dictionary and progress checklist. It keeps pricing transparent, bids comparable, and payments fair.
Why a BOQ Matters
- Transparent pricing: You see what you’re paying for—line by line.
- Comparable bids: Contractors price the same scope, so you compare apples to apples.
- Cost control: Makes variations (scope changes) easy to price and approve.
- Cash-flow planning: Helps phase payments by milestones.
- Dispute reduction: Clear quantities + clear rates = fewer arguments later.
What’s Inside a BOQ (Typical Structure)
- Preliminaries – Site setup, insurances, permits, temporary utilities, HSE, mobilization.
- Measured Works – The core trades, broken into work sections, e.g.
- Site clearance & earthworks
- Concrete & reinforcement
- Masonry & blockwork
- Roofing & waterproofing
- Doors, windows & glazing
- Finishes (plaster, paint, tiles)
- MEP (electrical, plumbing, drainage)
- External works (paving, fencing, landscaping)
- Prime Cost (PC) Items – Client-selects-brand later (e.g., sanitary ware, tiles).
- Provisional Sums (PS) – Allowances for uncertain scope (e.g., rock excavation).
- Preliminaries & General (P&G) Summary – Overheads not tied to one trade.
- Contingency – A percentage (often 5–10%) for small unknowns.
- Grand Summary – Totals per section and overall project cost.
How to Read a BOQ Line
Each line describes what, how much, and how it’s measured.
| Item No. | Description | Unit | Qty | Rate (UGX) | Amount (UGX) |
| 3.02 | 200mm solid block wall, mortar 1:4, includes scaffolding up to 3m | m² | 85 | 65,000 | 5,525,000 |
- Unit: How it’s measured—m² (area), m³ (volume), m (length), nr (number), sum (lump).
- Rate: Cost per unit (materials + labor + small tools + waste + overhead + profit).
- Amount: Qty × Rate.
Units of Measure (Quick Guide)
- m² — walls, plaster, tiling, painting, roofing sheets
- m³ — concrete, excavation backfill
- m — pipes, cables, skirtings, perimeter fencing
- nr — doors, windows, sanitary fixtures, light fittings
- sum — preliminaries, mobilization, specialized systems
What Builds Up a Rate? (Simple Example)
Example: 200mm blockwork per m²
Materials (per m²):
- Blocks (≈10 pcs/m²) @ 3,500 = 35,000 UGX
- Mortar cement & sand (≈0.015 m³ mix) = 7,500
- Water, additives, waste allowance = 1,000
Materials subtotal: 43,500
Labor:
- Masons + helpers (productivity ≈ 5 m²/day/team)
- Daily cost of team (e.g., 150,000) / 5 m² = 30,000
Labor subtotal: 30,000
Small tools & scaffolding: ≈ 2,500
Overheads & profit (say 10%): (43,500 + 30,000 + 2,500) × 10% ≈ 7,600
Indicative Rate: 43,500 + 30,000 + 2,500 + 7,600 ≈ 83,600 UGX/m²
Contractors’ rates vary by brand, location, access, height, finish level, and market prices.
Prime Cost (PC) Items vs Provisional Sums (PS)
- PC Items: You set an allowance for a yet-to-be-chosen product (e.g., “Toilet set PC = 600,000 UGX each”). If you later pick a 650,000 UGX model, you pay the difference + agreed handling.
- PS: A best-guess lump allowance for uncertain work (e.g., “PS = 8,000,000 UGX for landscaping”). Final payment adjusts to actual measured work and agreed rates.
Preliminaries & General (P&G)
Covers project-wide costs not tied to a single line item:
- Site office, storage, toilets, fencing, security
- Site power/water, equipment mobilization
- HSE gear and compliance
- Supervision, engineering control, program management
Often priced as lump sums or time-related rates (per week/month). These are real costs—cutting them recklessly risks safety and quality.
Variations (Changes After Contract)
Changes are normal—how you manage them matters.
- Describe the change (scope, drawings, location).
- Measure the quantity (m², m, nr, etc.).
- Apply existing BOQ rates where possible (keeps pricing consistent).
- New rate build-up if no suitable rate exists (show materials, labor, OHP).
- Approval in writing before work proceeds (Variation Order).
Common BOQ Pitfalls (and Easy Fixes)
- Vague descriptions: Leads to disputes. → Ask for brand/specs or performance standards.
- Missing items: Later appear as “extras.” → Cross-check drawings vs BOQ; add omissions before contract.
- Unbalanced pricing: Very low rate on one item, high on another. → Compare multiple bidders; watch PS/PC adjustments.
- Double counting: Same work in two sections. → Walk the drawings line by line.
- Ignoring waste/height/complexity: Rates explode on site. → Confirm scaffolding, access, and finishes in descriptions.
- Too little contingency: Prices move. → Keep 5–10% contingency outside the contract sum if possible.
How to Use a BOQ to Compare Bids
- Issue the same drawings, specs, and BOQ to all bidders.
- Request filled BOQs + a priced summary from each contractor.
- Check: Rates consistency, math errors, PC/PS assumptions, program duration.
- Normalize bids: adjust for different PC items and exclusions to compare fairly.
- Shortlist on both price and capability (experience, team, references, HSE record).
- Post-bid meeting to clarify program, cash flow, and key assumptions.
Payment & Cash-Flow with a BOQ
- Milestone schedule: Mobilization → Foundation → Superstructure → Roof → Finishes → Practical completion.
- Valuations: Monthly measurement of completed quantities × agreed rates = certified payment.
- Retention: Typically 5–10% held until defects liability period ends.
- Advance payment: Sometimes allowed against a bond, then recovered from interim payments.
Value Engineering (VE) Without Sacrificing Quality
- Material alternatives: Equivalent brands with proven warranties.
- Detail tweaks: Standard sizes to reduce waste (tile sizes, block modules).
- Scope clarity: Remove duplicated preliminaries when trades overlap.
- Buildability: Prefer details that simplify installation (fewer special cuts, safer access).
- Energy efficiency: Insulation, solar-ready roofing, LED/efficient fixtures reduce lifecycle cost.
Simple BOQ Snippet (Example)
SECTION 5: WALL FINISHES
5.01 Skim coat plaster 12mm, both sides of internal block walls m² 210 18,500 3,885,000
5.02 Primer + 2 coats quality emulsion, internal walls m² 210 12,000 2,520,000
5.03 Ceramic wall tiles 300×600 incl. adhesive & trims (wet areas) m² 38 78,000 2,964,000
SUBTOTAL SECTION 5 —— 9,369,000
Your First-Time Builder Checklist
✅ Have final drawings (plans, sections, elevations, MEP) before pricing.
✅ Use a standard BOQ format with clear descriptions and units.
✅ Define PC items and PS sums with realistic allowances.
✅ Agree variation rules (use existing rates first; new rates require build-ups).
✅ Keep a contingency (5–10%) outside the contract.
✅ Set payment milestones, retention, and defects period in the contract.
✅ Insist on as-builts & warranties at handover.
Key Terms (Mini-Glossary)
- BOQ: Bill of Quantities—line-item list of works for pricing & payment.
- Rate: Price per unit (includes materials, labor, overheads, profit).
- PC Item: Prime Cost allowance for client-selected products.
- PS: Provisional Sum for uncertain work scope.
- Preliminaries: Project-wide overheads (setup, HSE, supervision).
- Variation: Approved change to scope, quantity, or specification.
- Retention: Withheld amount to ensure defects are fixed.
Final Word
A good BOQ is your cost control toolkit—it translates drawings into prices, turns progress into fair payments, and turns changes into manageable numbers. Invest time to get it right upfront, and your build will run smoother, faster, and with fewer surprises.
