How do you estimate construction costs

Estimating construction costs in Singapore involves several key steps and considerations, particularly given the current market landscape.

Factors Influencing Costs

Construction costs in Singapore are significantly influenced by a shortage of skilled labour, especially in the mechanical and electrical work sectors, which has led to higher labour costs. Additionally, high material costs due to global supply chain disruptions and high demand play a crucial role. For example, the cost of steel bars and cement has seen substantial increases in recent years.

Estimation Methods

Several estimation methods are used at different stages of a construction project:

Conceptual Estimation

In the early stages, such as the planning or schematic design stage, the Rough Order of Magnitude (ROM) method is often used. This method estimates construction costs based on the total gross area of the project.

Semi-Detailed Estimation

During the design development stage, a more detailed estimation is made using lists of expected materials and quantities. This helps in evaluating the budget in relation to the proposed design.

Detailed Estimation

As the project nears the completion of its design phase, estimators use the construction documents stage to establish a more realistic budget based on nearly finalized plans. This estimate considers all project specifications and provides a detailed overview of anticipated costs.

Specific Estimation Techniques

• Unit Cost Estimating: Assigns unit costs to each component of the construction process, allowing for quick adjustments.
• Analogous Estimating: Uses costs from similar past projects as a reference to gauge expected expenses.
• Parametric Estimating: Utilizes statistical data and formulas to predict costs based on project parameters, such as cost per square foot.
• Bottom-Up Estimating: Breaks the project into smaller components, estimates costs for each part, and aggregates these estimates for a comprehensive view.

Current Market Considerations

Given that Singapore is ranked as the fourth-most expensive construction market in Asia, with an average construction cost of approximately US$2,079 per square meter, it is crucial to factor in the volatility of tender prices, which are expected to increase by 10-15% due to labour and material cost increases.

By considering these factors and using the appropriate estimation methods at each stage of the project, stakeholders can make informed decisions regarding project viability, financing, and budget management.