Quick Answer: To prepare a BOQ for a residential building in Kenya, take off quantities from architectural and structural drawings using standard measurement rules (SMM7 or NRM2), organise them into trade sections, then price each item using current market rates and submit the final document for tendering.
A Bill of Quantities is one of the most critical documents in any construction project. Without it, contractors cannot price accurately, clients cannot compare tenders fairly, and project managers cannot control costs on site.
If you are a quantity surveying student or a junior QS working on your first residential project, this guide breaks down the exact process you need to follow .. from reading the drawings to submitting a priced document.
What Is a Bill of Quantities and Why It Matters
A Bill of Quantities (BOQ) is a document that lists all the materials, labour, and work items needed to complete a construction project, together with their quantities and unit rates.
In Kenya, BOQs are prepared in accordance with the Association of Architectural and Quantity Surveyors (AAQS) standards and follow the measurement rules set out in the Standard Method of Measurement (SMM). Every item must be described clearly enough for a contractor to price it without needing to ask questions.
The BOQ is not just a pricing tool. On site, it becomes a contract document. It is used to value work done, assess variations, and process monthly payment certificates. A poorly prepared BOQ creates disputes. A well-prepared one keeps the project financially clean from start to finish.
Step 1: Read and Understand the Drawings Before You Take Off Any Quantities
This is where most students go wrong. They start measuring before they understand what they are measuring.
Before taking off any quantities, study the architectural plans, sections, and elevations alongside the structural drawings. Note the wall thicknesses, floor-to-floor heights, roof type, foundation depth, and any special finishes. Cross-check the drawing list to confirm all drawings are available and coordinated.
If anything is unclear, raise a Request for Information (RFI) to the architect or engineer before proceeding. Guessing at this stage creates errors that compound through the entire document.
Step 2: Organise the BOQ into Work Sections
A residential BOQ in Kenya is typically divided into trade sections, each priced by the relevant contractor or subcontractor. Organising clearly from the start makes the tendering process efficient and reduces pricing errors.
| Section | What It Covers |
|---|---|
| Preliminaries | Site establishment, supervision, insurance, plant hire |
| Substructure | Excavation, foundations, ground floor slab |
| Superstructure | Walling, columns, beams, floor slabs |
| Roofing | Timber roof structure, roofing sheets or tiles, gutters |
| Finishes | Plastering, tiling, painting, ceilings, screeds |
| Joinery | Doors, windows, frames, ironmongery |
| Plumbing and Drainage | Water supply, sanitary ware, drainage pipes, septic system |
| Electrical | Wiring, fixtures, switchgear, consumer units |
| External Works | Boundary walls, paving, landscaping, external drainage |
This structure mirrors how contractors organise their subcontractors, which makes pricing and comparison of tenders efficient for the client and the project QS.
Step 3: Take Off Quantities Accurately from the Drawings
Taking off is the process of measuring quantities directly from the drawings. In Kenya, this is done using the SMM7 rules or the NRM2 (New Rules of Measurement) published by RICS, which many firms are transitioning to.
Key principles to apply:
- Work to a system. Measure from left to right, then top to bottom, and always in the same sequence across drawings.
- Use dimension paper. Record timesing factors clearly so your supervisor can check your work and verify every number.
- Measure net, deduct separately. Measure walls in full, then deduct openings for doors and windows as distinct line items.
- State the unit clearly. Each item must show the unit (m, m², m³, nr, or sum), quantity, description, unit rate, and total amount.
The truth is, accuracy at this stage determines the quality of the entire document. A 10% error in concrete volumes for the ground floor slab can cost a project hundreds of thousands of shillings .. and it traces directly back to the take-off.
Step 4: Price the BOQ Using Current Market Rates
Once quantities are confirmed, apply rates to each item. For a Kenyan residential building, reliable sources for current rates include the AAQS Schedule of Rates, Ministry of Public Works standard rates, current quotations from material suppliers such as Bamburi Cement and Devki Steel, and direct rates from subcontractors for specialist trades.
Every rate must cover material supply, labour, plant where applicable, and a contribution to overheads and profit. Preliminaries are typically priced as 8% to 15% of the overall construction cost, depending on project complexity and programme duration.
In simple terms.. if you are pricing mass concrete for a strip foundation, your rate must account for the cost of cement, sand, ballast, water, mixer hire, labour to mix and pour, and curing. Leaving out any one of these will underprice the item and create a financial dispute later in the project.
Step 5: Check, Format, and Submit the Final Document
Before submission, review every section for arithmetic errors, missing items, and inconsistent descriptions. A BOQ with pricing errors or missing trade sections will generate contractor queries during tendering and slow down the entire process.
Format the document professionally: clear headings, consistent units, and a summary page that totals each section. In Kenya, the summary sheet typically separates construction costs, preliminaries, contingencies (usually 5% to 10%), and consultant fees before arriving at the final contract sum.
Honestly, the difference between a junior QS and a competent one is not just how fast they measure. It is how clearly they describe, how accurately they price, and how cleanly they present the final document.
Frequently Asked Questions
Q: What is the difference between a BOQ and a BQ?
BOQ (Bill of Quantities) and BQ are the same document .. the terms are used interchangeably in Kenya and across the East African construction industry. The abbreviation preferred depends on the firm or institution you are working with.
Q: Can a civil engineering student prepare a BOQ?
Yes. Civil engineering students are trained in quantity surveying as part of their curriculum. In practice, professional-standard BOQ preparation requires working knowledge of measurement rules (SMM7 or NRM2), drawing interpretation, and current pricing data .. skills that develop through practice on real projects.
Q: What software is used for BOQ preparation in Kenya?
Most QS firms in Kenya use Microsoft Excel for BOQ preparation and cost management. Some firms use CostX or Buildsoft for larger commercial projects. For small residential projects, Excel with a well-structured template is the industry standard and is entirely sufficient.
Preparing a BOQ for a residential building is a skill that sits at the heart of cost management in construction. The document you produce will influence tendering, contract management, and every valuation from ground level to roof. Get the measurements right, organise the sections clearly, and price accurately using current data.
Whether you are a QS student completing your first take-off or a site engineer trying to understand how the contract document was assembled, the BOQ is worth understanding in detail.
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Thank you for the kind word. The BoQ guide covers a lot of ground, so work through the cost breakdown section carefully when you are ready to apply it on a real project. For more in-depth guidance, join our WhatsApp community at +254731393520 — we cover quantity surveying and estimation topics there regularly.