Cost Estimation in Structural Engineering

Cost Accuracy of FS vs FEED vs DED The accuracy of cost estimates varies depending on the phase of the project, from the initial feasibility study to the detailed engineering design (DED). Each phase involves different levels of detail and certainty, which impacts the precision of the cost estimates. Here's an overview of the expected accuracy for each phase: 1. **Feasibility Study** - **Purpose**: To assess the viability of a project before significant resources are committed. - **Detail Level**: Low. Rough estimates based on preliminary data and assumptions. - **Accuracy Range**: Typically -30% to +50%. - **Methods**: Conceptual estimating techniques, analogous estimates, parametric models, or expert judgment. - **Considerations**: High level of uncertainty due to limited information. Includes rough order-of-magnitude (ROM) estimates. 2. **Front-End Engineering Design (FEED)** - **Purpose**: To refine project scope, define major components, and develop a more precise budget. - **Detail Level**: Moderate to high. More detailed than feasibility, but not as comprehensive as DED. - **Accuracy Range**: Typically -15% to +30%. - **Methods**: Detailed quantity take-offs, preliminary design specifications, vendor quotes, and more accurate cost databases. - **Considerations**: Includes preliminary engineering and design work, risk assessments, and early procurement planning. 3. **Detailed Engineering Design (DED)** - **Purpose**: To finalize all project designs, specifications, and procurement plans. - **Detail Level**: High. Comprehensive and detailed engineering and design. - **Accuracy Range**: Typically -5% to +15%. - **Methods**: Detailed engineering drawings, complete material take-offs, finalized vendor and subcontractor quotes, and detailed cost databases. - **Considerations**: Most precise phase with minimized uncertainties, incorporating all finalized details of the project. Best Practices to Enhance Accuracy: 1. **Data Quality and Detail**: Use high-quality data and detailed designs at each phase to improve accuracy. 2. **Experience and Expertise**: Leverage the experience of project managers, engineers, and cost estimators. 3. **Historical Data**: Utilize historical project data to inform estimates and validate assumptions. 4. **Contingency Planning**: Include appropriate contingency allowances to manage unforeseen changes. 5. **Regular Reviews**: Continuously update and refine estimates as more information becomes available. 6. **Software Tools**: Employ specialized cost estimation software to enhance precision and manage complex data. By following these practices, you can ensure that your cost estimates are as accurate and reliable as possible, providing a solid foundation for successful project management and execution. #ProjectManagement #CostEstimation #Project

⚡️ Free n8n CAD (BIM) workflow: 𝗔𝗨𝗧𝗢𝗠𝗔𝗧𝗜𝗖 𝗖𝗢𝗦𝗧 𝗘𝗦𝗧𝗜𝗠𝗔𝗧𝗜𝗢𝗡 𝗙𝗢𝗥 𝗚𝗥𝗢𝗨𝗣𝗦 𝗔𝗡𝗗 𝗧𝗛𝗘 𝗘𝗡𝗧𝗜𝗥𝗘 𝗣𝗥𝗢𝗝𝗘𝗖𝗧 𝗪𝗜𝗧𝗛 𝗟𝗟𝗠 (works with Revit, IFC, DWG) This is a ready-made solution on n8n that allows you to automatically calculate the cost of different groups of elements and the entire construction project based on data from Revit, IFC, or DWG files. It uses any LLM (such as Grok, OpenAI, Anthropic) — they automatically classify materials, search for prices in databases and online sources, and generate reports in a convenient format. 𝗛𝗼𝘄 𝗱𝗼𝗲𝘀 𝗶𝘁 𝘄𝗼𝗿𝗸? 1️⃣ Revit/IFC/DWG are automatically converted into a structured DataFrame 2️⃣ LLM determines the grouping parameters, classifies materials, and finds current prices in databases and online 3️⃣ Reports and dashboards are generated automatically — visualizations and tables appear without manual routine work The input is an RVT or IFC project, and the output is a finished document with a detailed analysis of groups by cost. At the same time, any parameter in the open workflow can be customized for your project (grouping process, country for prices, LLM API keys, or your own models). The average processing speed for one group of elements is 5 to 15 seconds, depending on the LLM you choose. 𝗪𝗵𝗮𝘁 𝗱𝗼𝗲𝘀 𝘁𝗵𝗶𝘀 𝗺𝗲𝗮𝗻 𝗳𝗼𝗿 𝘁𝗵𝗲 𝗺𝗮𝗿𝗸𝗲𝘁? Traditional roles—BIM coordinator, BIM manager, estimator, designer—are gradually ceasing to be “manual data operators.” The key competency is no longer how to manually check a table and find the right group, but how to correctly compile a prompt, adjust process parameters, and analyze the result. 𝗥𝗲𝗮𝗹-𝗹𝗶𝗳𝗲 𝗲𝘅𝗮𝗺𝗽𝗹𝗲: Using ChatGPT, it took about 30 minutes to estimate the cost of a standard Revit project from Autodesk (rac_basic_sample.rvt). The total cost of the rac_basic_sample project is €647,700, with glass and walls accounting for the lion's share. The workflow even calculated the cost of the “vase on the table,” estimating it at €70. The XSLS and the HTML report received after the workflow is completed can be found in our telegram group ⬇️). 📥 𝗟𝗶𝗻𝗸 𝘁𝗼 𝘁𝗵𝗲 𝘄𝗼𝗿𝗸𝗳𝗹𝗼𝘄: 🔗 GitHub: https://lnkd.in/eSFxTf6m Workflow file: n8n_Construction_Price_Estimation_with_LLM.json Instructions inside the repo — import the workflow into n8n ➡️ specify the file, grouping, and country ➡️ add the LLM API keys ➡️ and run. Everything works out of the box, but the accuracy of the prompts can be easily adjusted to suit your experience. Advice: the highest recognition and classification accuracy in my tests was given by Claude 4 Opus and Grok4. P.S. If anyone has RVT or IFC projects with already calculated costs, please write to me. I will be happy to test them on real data and fine-tune the prompts for your case. ♻️ Feel free to share this post with colleagues who are struggling with data quality and calculations, perhaps the headache and routine of the task can be solved by LLM

Cost Estimating 🔹 What is Cost Estimating? Predicting project cost from scope + drawings + specs + market data. Used for: Tendering | Budgeting | Cost Control. Golden rule: realistic, defendable, measurable + market-based. 🔹 Levels of Accuracy: Conceptual (-25%/+40%) – Feasibility Preliminary (-15%/+20%) – Budget approval Detailed (-5%/+10%) – Tender/BOQ Control (based on actual BOQ/contracts) – Payments 🔹 Components of an Estimate: 1. Direct costs (labour, materials, plant) 2. Indirect costs (site + head office overheads) 3. Profit & Risk (margin + contingencies) 🔹 Step-by-Step Process: 1. Understand the scope 2. Quantity Take-Off (QTO) 3. Build unit rates  Unit Rate = Materials + Labour + Plant + OH + Profit 4. Add preliminaries 5. Include risk/contingencies (5–10%) 6. Review & benchmark 🔹 Quick Example: Blockwork 200 m² → 109 SAR/m² → Total = 21,800 SAR 🔹 Common Junior Mistakes: ❌ Ignoring wastage ❌ Overlooking site conditions ❌ Using “market rates” with no breakdown ❌ Forgetting preliminaries ❌ Copy-pasting old rates 🔹 Pro Tips: ✅ Keep a rate build-up sheet ✅ Build your own rate database ✅ Cross-check against cost/m² benchmarks ✅ Never submit without risk allowance ✅ Accuracy matters more than being the cheapest #QuantitySurveying #CostEstimating #BOQ

Cost Estimation * Cost estimation is the process of forecasting the financial resources required to complete a project within its defined scope and timeframe.    Purpose: To provide an approximate budget for the project. To determine the feasibility and economic viability of the project. To assist in project planning and decision-making. Stages: Initial Estimation: Broad estimates made during the early stages of the project based on limited information. Refined Estimation: More detailed and accurate estimates made as the project scope becomes clearer and more information is available. Techniques: Analogous Estimating: Using historical data from similar projects. Parametric Estimating: Using statistical relationships between historical data and other variables. Bottom-Up Estimating: Breaking down the project into smaller components and estimating the cost of each component. Expert Judgment: Consulting with experts who have experience with similar projects. Output: A detailed cost estimate document that outlines the expected financial requirements for the project. Cost Control *Cost control is the process of monitoring and managing project expenditures to ensure that the project stays within the approved budget. Purpose: To manage and reduce cost overruns. To ensure the project is completed within the approved financial resources. To provide data for financial reporting and project decision-making. Stages: Budget Baseline: Establishing a baseline budget based on the cost estimation. Monitoring: Continuously tracking actual costs against the budget. Controlling: Taking corrective actions to address any deviations from the budget. Techniques: Earned Value Management (EVM): Measuring project performance and progress in an objective manner. Variance Analysis: Identifying and analyzing differences between planned and actual costs. Trend Analysis: Using historical data to predict future performance. Change Control: Managing changes to the project scope that may affect costs. Output: Regular cost reports and updates. Corrective action plans to address any deviations. Final cost performance assessment at project completion. Key Differences Focus: Cost estimation focuses on predicting the financial resources needed before the project starts. Cost control focuses on managing and adjusting the project budget during execution. Timing: Cost estimation is primarily a pre-project activity. Cost control is an ongoing activity throughout the project lifecycle. Objective:  The objective of cost estimation is to create a financial plan.  The objective of cost control is to adhere to the financial plan and mitigate deviations. Both cost estimation and cost control are crucial for effective project management. Accurate cost estimation sets the foundation for a realistic budget, while diligent cost control ensures that the project stays on track financially, ultimately contributing to the project's success. #Cost_Estimation #Cost_control #Safeek #LinkedIn

Estimating costing in projects is a key part of project cost management. It involves forecasting how much money will be required to complete project activities. Here’s a breakdown of how it’s done, including the types, tools, and techniques used: 🔹 1. Cost Estimating – Definition Cost estimating is the process of developing an approximation of the monetary resources needed to complete project activities. It includes direct and indirect costs, such as: Labor Materials Equipment Services Facilities Overheads Contingency reserves 🔹 2. Types of Cost Estimates Estimate Type Description Accuracy Range Used When Rough Order of Magnitude (ROM) Broad estimate for feasibility phase -25% to +75% Early project phases Budget Estimate More refined, used for funding requests -10% to +25% Planning phase Definitive Estimate Most accurate, used for baselines and control -5% to +10% Execution/Pre-construction 🔹 3. Common Cost Estimating Techniques A. Analogous Estimating (Top-Down) Based on historical data from similar projects. Fast but less accurate. ✅ Example: Last bridge project cost $1.2M, so estimate similar cost. B. Parametric Estimating Uses mathematical models based on historical data and variables. ✅ Example: $50 per meter of cable × 1,000 meters = $50,000. C. Bottom-Up Estimating Estimates each activity or work package and sums them up. Most accurate but time-consuming. ✅ Example: Labor (300 hrs × $40/hr) + Materials ($5,000) + Equipment ($2,000). D. Three-Point Estimating Considers uncertainty with three estimates: Optimistic (O), Most likely (M), Pessimistic (P) Expected Cost (PERT) = (O + 4M + P) / 6 ✅ Example: ($10K + 4×$12K + $15K) / 6 = $12.17K E. Expert Judgment Use the knowledge of experienced professionals or SMEs. ✅ Often used in combination with other methods. F. Reserve Analysis Adds contingency for identified risks and management reserve for unknowns. ✅ Example: Add 10% of total cost for contingency. 🔹 4. Outputs of Cost Estimating Process Cost estimates Basis of estimates (assumptions, methodology) Project documents updates (e.g. risk register, schedule) 🔹 5. Tools & Software Microsoft Project, Primavera P6 Spreadsheets (Excel) Cost estimating software like CostX, RSMeans, or specialized ERP tools Would you like an example of a cost estimate worksheet or a template for your type of projects (e.g. construction, electrical, hydraulic)? #costing #estimating

Quantity Take-Off (QTO) Quantity Take-Off is a process used by Quantity Surveyors (QS), Estimators, and Engineers to measure and list the quantities of materials, labor, and works required to complete a construction project. It is the first step before preparing cost estimates, tender pricing, or bills of quantities (BOQ). Purpose of Quantity Take-Off To find out exactly how much material, labor, and equipment is needed. To help prepare accurate cost estimates and budgets. To support tendering, procurement, and cost control. To ensure no part of the work is missed during pricing. How Quantity Take-Off is Done 1. Study Drawings and Specifications: Architectural drawings Structural drawings MEP (Mechanical, Electrical, Plumbing) drawings Project specifications 2. Measure Quantities: Measure dimensions (length, area, volume) directly from drawings. Take measurements using scaling tools, CAD software, or BIM models. 3. List Out Items: For each trade (concrete, masonry, painting, etc.), list the quantities. Example: How many cubic meters of concrete, how many square meters of tiles. 4. Apply Units of Measurement: Use correct units: m³ for concrete, m² for plastering, tons for steel, numbers for doors. 5. Prepare Take-Off Sheets or Software Entry: All measurements are organized neatly for further costing. Typical Items Measured in QTO Earthworks: Excavation, filling Concrete Works: Foundation, slab, beams Masonry Works: Blockwork, brickwork Steel Works: Reinforcement bars, structural steel Finishes: Plastering, painting, tiling MEP Works: Pipe lengths, cable runs, ducts Example (Simple) Suppose the drawing shows a concrete slab of: Length = 10 meters Width = 8 meters Thickness = 0.15 meters Volume of concrete = Length × Width × Thickness = 10 × 8 × 0.15 = 12 cubic meters (m³) So, in the Quantity Take-Off sheet, you will record: "Concrete for slab = 12 m³" UAE Construction Practice In the UAE, Quantity Take-Off is very important at: Tender Stage: Estimators prepare competitive pricing. Post-Contract Stage: QS uses site measurements for interim valuations and final accounts. Software Tools: AutoCAD, Revit, PlanSwift, Bluebeam, and CostX are commonly used. Important: Must follow the project's method of measurement (POMI, NRM, CESMM, etc.) Must double-check drawings and specification notes carefully. Summary Quantity Take-Off is the foundation of cost management in construction. A small mistake in QTO can lead to big errors in the cost estimate, tender, or contract value. It requires accuracy, attention to detail, and understanding of construction methods.