Bill of Quantities Estimator — Cheat Sheet
Quick-reference cheat sheet for the Bill of Quantities Estimator tool.
Published 27 May 2026
Bill of Quantities Estimator
Quick-reference companion for the free Portal tool
What This Tool Does
The Bill of Quantities (BoQ) Estimator is a powerful tool designed to assist South African architects in generating preliminary cost estimates for building projects. It leverages a database of local material costs, labour rates, and typical construction methodologies to provide a high-level, indicative BoQ. This tool is invaluable during the initial design phases (e.g., Concept Design, Design Development) when quick cost feedback is crucial for informing design decisions and managing client expectations.
Use this tool when you need to provide a client with a rough order of magnitude cost for a proposed project, evaluate the cost implications of different design options, or prepare for initial budget discussions. It streamlines the typically time-consuming process of manual estimation, allowing architects to focus more on design innovation while maintaining a realistic understanding of project viability. It's essential for all architects and project managers working on residential, commercial, or light industrial projects across South Africa.
Step-by-Step Usage Guide
Begin by entering fundamental project information. This includes the project name, type (e.g., Residential, Commercial, Retail), and most critically, the project location. The location is vital as it influences material transport costs, labour rates, and climate zone considerations (e.g., for SANS 10400-XA energy efficiency).
Project Name: "Sandton Office Block"
Project Type: "Commercial"
Location: "Johannesburg, Gauteng" (Use the dropdown/lookup feature for accuracy)
Input the estimated gross floor area (GFA) of the building and the number of storeys. This provides the tool with the primary scale of the project. Be accurate here, as it's a major cost driver.
Gross Floor Area (GFA): 2500 m²
Number of Storeys: 5
Select the primary structural system (e.g., concrete frame, steel frame, load-bearing masonry) and the external wall and roofing materials. These choices significantly impact cost. Consider local availability and typical construction practices.
Structural System: "Reinforced Concrete Frame"
External Walls: "Plastered Brickwork (Double Leaf)"
Roofing: "Concrete Slab with Waterproofing & Insulation"
Specify the window-to-wall ratio and the type of glazing. This is critical for energy efficiency compliance (SANS 10400-XA) and impacts both material and installation costs.
Window-to-Wall Ratio: 35%
Glazing Type: "Aluminium Frame, Double Glazed (Low-E)"
Choose the desired quality level for internal finishes (e.g., basic, standard, premium) and the complexity of services (e.g., standard electrical, advanced HVAC, specialized plumbing). This broadly categorizes the fit-out.
Internal Finishes: "Standard Commercial Grade"
Services Level: "Standard HVAC & Electrical, Basic Fire Suppression"
Click the "Generate Estimate" button. The tool will process your inputs and present a breakdown of estimated costs, typically categorized by major building elements (e.g., Substructure, Superstructure, Finishes, Services). Review the summary and individual line items for reasonableness.
A table showing estimated costs for: Earthworks, Foundations, Structure, External Walls, Roofing, Windows & Doors, Internal Finishes, Wet Services, Electrical Services, HVAC, etc., along with a total estimated project cost (excl. VAT and professional fees).
Common Scenarios & Expected Results
| Scenario | Input | Expected Output (Indicative) |
|---|---|---|
| Small Residential - Basic |
Project Type: Residential Location: Pretoria GFA: 180 m² Storeys: 1 Structure: Load-bearing Masonry Finishes: Basic |
Total Est. Cost: R1.8M - R2.5M (Lower cost/m² due to simplicity) |
| Medium Commercial - Standard |
Project Type: Commercial Location: Cape Town GFA: 1500 m² Storeys: 3 Structure: Concrete Frame Finishes: Standard Commercial Glazing: Double Glazed |
Total Est. Cost: R27M - R38M (Mid-range cost/m², considering higher labour in CT) |
| High-End Retail - Complex |
Project Type: Retail Location: Umhlanga, KZN GFA: 800 m² Storeys: 2 Structure: Steel Frame Finishes: Premium Services: Advanced HVAC, specialized lighting |
Total Est. Cost: R18M - R26M (Higher cost/m² due to premium finishes & complex services) |
| Industrial Warehouse - Basic |
Project Type: Industrial Location: East London GFA: 5000 m² Storeys: 1 Structure: Steel Portal Frame Finishes: Basic Industrial |
Total Est. Cost: R35M - R50M (Lower cost/m² due to large scale and basic finishes) |
Pro Tips
Refine by SANS 10400-XA: Pay close attention to your glazing choices and insulation levels. The tool incorporates SANS 10400-XA energy efficiency requirements. Specifying higher performance glazing (e.g., double-glazed, low-E) and adequate insulation will increase initial costs but contribute to lower operational costs and better compliance. Use the tool to compare different compliance strategies.
Location Matters: The "Location" field is crucial. Prices vary significantly across South Africa due to logistics, availability of skilled labour, and regional supplier networks. For instance, Cape Town and Johannesburg often have higher labour rates than smaller towns. Always use the most specific location available.
Iterate Your Design: Don't treat this as a one-time calculation. Use the BoQ Estimator to rapidly test different design options. Want to see the cost impact of a concrete frame vs. a steel frame? Or a plastered brick wall vs. a lightweight panel system? Input the changes and re-generate the estimate to inform your design decisions.
Disclaimer & Contingency: Always communicate to clients that this is a preliminary estimate. It does not replace a detailed BoQ prepared by a Quantity Surveyor. Advise clients to budget for a contingency sum (typically 10-15% for early stages) on top of the estimate to account for unforeseen circumstances and design development.