Estimate Based on Working Drawings

Test Your Knowledge

Quiz: Estimating Based on Working Drawings (Class A Estimates)

Instructions: Choose the best answer for each question.

1. What is the primary source of information for a Class A Estimate? a) Previous project budgets b) Contractor bids c) Working drawings d) Market research

2. Which of the following is NOT a key characteristic of a Class A Estimate? a) Detailed breakdown of project elements b) Based on preliminary sketches c) Specialized expertise required d) Iterative process

3. Why are Class A Estimates considered vital for risk management? a) They guarantee project completion within budget. b) They identify potential cost overruns early on. c) They eliminate the need for contingencies. d) They predict future market fluctuations.

4. Which of the following is an example of an element that would be included in a Class A Estimate for a commercial building project? a) Cost of marketing materials b) Salary of the project manager c) Number of employees working on the project d) Quantity of concrete for the foundation

5. What is the main purpose of a Class A Estimate? a) To determine the profitability of a project. b) To secure funding for a project. c) To provide an accurate cost projection for a project. d) To finalize the project schedule.

Exercise: Class A Estimate Application

Scenario: You are tasked with creating a preliminary Class A Estimate for a residential renovation project. The working drawings indicate the following:

• Kitchen Remodel: New cabinets, countertops, flooring, appliances (including a new refrigerator, oven, and dishwasher).
• Bathroom Remodel: New shower, bathtub, vanity, flooring, and fixtures.
• Exterior Painting: Repainting the entire house.

Instructions:

1. Break down the project into its major components (e.g., kitchen remodel, bathroom remodel, exterior painting).
2. List the key elements within each component (e.g., cabinets, countertops, flooring for the kitchen).
3. For each element, consider the materials, labor, and potential contingencies that would need to be factored into the estimate.
4. Provide a brief description of how you would research costs for each element (e.g., online resources, material suppliers, local contractors).

Techniques

Estimating Based on Working Drawings: A Deeper Dive into Class A Estimates

This expanded version breaks down the topic into separate chapters.

Chapter 1: Techniques

Estimating based on working drawings (Class A estimating) relies on a variety of techniques to achieve accuracy and detail. These techniques can be broadly categorized as:

• Quantity Takeoff (QTO): This is the foundational technique. It involves meticulously extracting quantities of materials from the working drawings. This might involve counting the number of bricks, measuring the area of flooring, or calculating the volume of concrete needed. Software tools are often employed to automate this process, but manual takeoffs remain crucial for complex details. Different methods exist, including:

  • Direct Measurement: Measuring directly from the drawings using rulers and calculators.
  • Digital Takeoff: Using specialized software to automatically measure quantities from digital drawings (PDFs, DWGs, etc.).
  • Factor Method: Using pre-determined factors (e.g., square footage per unit) for faster estimation of certain items.

• Pricing: Once quantities are determined, each item needs a price assigned. This requires access to up-to-date material costs, labor rates (including labor burden), and equipment rental costs. Factors to consider include:

  • Material Cost Fluctuations: Pricing should account for potential market changes.
  • Labor Rates: Regional variations and union/non-union status significantly impact labor costs.
  • Equipment Costs: Rental rates, fuel, and operator costs need to be included.
  • Markup: A percentage added to cover overhead, profit, and unforeseen expenses.

• Cost Modeling: This involves assembling all the individual costs into a comprehensive project cost model. This model often utilizes spreadsheets or dedicated estimation software to track costs, allowing for easy adjustments and "what-if" scenarios. Advanced techniques include parametric modeling where cost is dynamically linked to design changes.

• Contingency Planning: A critical aspect of Class A estimating involves building in a contingency buffer to account for unforeseen issues, material price increases, or schedule delays. This is often expressed as a percentage of the total estimated cost.

Chapter 2: Models

Several models can be employed within the Class A estimating process, each with its own strengths and weaknesses. The choice of model often depends on project complexity and available resources:

• Unit Cost Model: This model focuses on establishing unit costs for various elements (e.g., cost per square foot of flooring, cost per linear foot of wall). It's relatively straightforward but can lack precision for complex projects.

• Component Cost Model: This model breaks the project into individual components (foundations, framing, roofing, etc.), estimating costs for each. It provides more detail than the unit cost model but still relies on some generalizations.

• Resource-Based Model: This model meticulously lists every resource needed (materials, labor hours, equipment days) with associated costs. It's the most detailed approach, enabling accurate cost forecasting but demands significant effort.

Chapter 3: Software

Various software solutions facilitate the Class A estimating process. These tools range from simple spreadsheets to sophisticated dedicated estimation platforms. Key features to look for include:

• Quantity Takeoff Capabilities: Automated measurement tools significantly speed up the QTO process.

• Database Management: Access to up-to-date material and labor cost databases.

• Reporting and Visualization: Tools for generating detailed reports and visualizing cost breakdowns.

• Integration with CAD software: Seamless data transfer between CAD drawings and the estimation software.

Examples of popular software include:

• PlanSwift
• On-Screen Takeoff
• Estimating Software by Sage
• CostOS
• Microsoft Excel (with add-ons)

Chapter 4: Best Practices

Effective Class A estimating demands adherence to best practices:

• Clearly Defined Scope: The project's scope must be explicitly defined to avoid ambiguities and omissions.

• Accurate Drawings: Using current and complete working drawings is paramount. Any revisions or changes need to be incorporated promptly.

• Experienced Estimators: The estimation process should be overseen by skilled and knowledgeable estimators.

• Regular Updates: Costs should be regularly reviewed and updated to reflect market fluctuations.

• Collaboration: Collaboration between estimators, designers, and contractors is essential for accuracy.

• Documentation: Maintaining thorough documentation of the entire estimation process is crucial for auditing and future reference.

• Quality Control: Implementing robust quality control checks helps to identify and correct errors.

Chapter 5: Case Studies

(This section would require specific examples. Below are outlines for potential case studies. Real-world data would replace the placeholder information.)

• Case Study 1: High-Rise Residential Building: Discuss how a Class A estimate helped accurately predict the cost of a high-rise residential building, highlighting the challenges of managing complex quantities of materials and labor. Include specific examples of cost breakdowns and contingency planning. Mention the software used. Show how the estimate facilitated negotiations with contractors.

• Case Study 2: Large-Scale Infrastructure Project: Examine a Class A estimate for a bridge or highway construction project. Focus on the use of advanced modeling techniques and the management of significant uncertainties related to site conditions and potential delays. Detail the process of incorporating detailed material quantities and specialized labor requirements into the estimate.

• Case Study 3: Renovation Project: Illustrate how Class A estimating can be applied to a complex renovation project, emphasizing the challenges of dealing with unforeseen conditions and hidden costs. Discuss the iterative nature of the estimating process and the importance of regular updates.

By expanding on these chapters with specific examples and detailed information, a comprehensive guide to estimating based on working drawings can be created.