Indirect Costs, Contingencies, and Profit
Learning Objectives
- Understand the difference between project overhead and general overhead.
- Learn how to calculate and apply contingencies for unknown risks.
- Understand how profit is determined and applied to the estimated cost.
- Calculate the final bid price using direct costs, indirect costs, contingency, and profit.
The Complete Estimate
While direct costs (materials, labor, equipment) form the bulk of the raw field expenses, an estimate is dangerously incomplete without indirect costs, contingencies, and profit. These are expenses that cannot be easily or directly attributed to a single physical construction activity, yet they are absolutely essential for running the business, managing the site, and ensuring financial survival.
Indirect Costs
Categories of Indirect Costs
Indirect costs are typically divided into two distinct categories: Project Overhead and General Overhead.
1. Project Overhead (General Conditions or Job Site Overhead)
Understanding Project Overhead
These costs are specific to a particular project but support the entire operation holistically rather than specific individual tasks (like pouring concrete). They are often referred to as "General Conditions."
Examples of Project Overhead
- Site Management and Supervision: Salaries of the Project Manager, Site Superintendent, Project Engineer, safety officers, and administrative staff dedicated full-time to the site.
- Temporary Facilities: Renting and setting up site office trailers, secure storage containers, portable toilets, temporary fencing, and access roads.
- Temporary Utilities: Electricity for tools and site lighting, municipal water for dust control and concrete curing, internet, and communication services for the site office.
- Mobilization/Demobilization: The initial heavy cost of moving equipment, trailers, and personnel to the site, and the cost of cleaning up and removing them at project completion.
- Permits and Fees: Building permits, environmental impact permits, utility connection fees, and dumping fees.
- Safety and Cleanup: Personal Protective Equipment (PPE) for visitors, daily site cleaning labor, dumpsters, and safety signage.
Estimating Project Overhead
Project overhead is usually estimated as a percentage of the total direct costs.
For preliminary estimates, project overhead is typically calculated as a flat percentage, ranging from 5% to 15% of the total direct cost, heavily depending on project complexity, location, and schedule duration. For detailed hard bids, estimators will calculate project overhead item-by-item (creating a detailed "General Conditions Estimate" based on the project schedule in months) instead of using a flat percentage for greater accuracy.
2. General Overhead (Home Office Overhead)
Understanding General Overhead
These are the ongoing costs of running the construction company's central office, regardless of whether a specific project is active. These costs must be proportionately distributed and absorbed by all the company's active projects for the firm to remain solvent.
General overhead is universally applied as a flat percentage of the total direct costs, typically ranging from 5% to 10% for most construction firms.
Examples of General Overhead
- Executive and Administrative Salaries: CEO, accounting department, HR, full-time estimating staff.
- Home Office Expenses: Rent or mortgage for the corporate office, office utilities, standard office supplies, estimating and accounting software subscriptions.
- Marketing and Legal Fees: Advertising, proposal development, legal counsel retainers.
- Corporate Insurance: General liability and umbrella insurance policies covering the entire firm globally.
Bonds vs. Insurance
Financial Guarantees vs. Risk Transfer
Both bonds and insurance are financial instruments required on projects and carried as indirect costs, but their fundamental mechanics are entirely different.
Bonds vs. Insurance
- Insurance: A two-party agreement between the contractor and the insurance company. It transfers the financial risk of accidental loss (e.g., a worker injury covered by Worker's Compensation, or a fire destroying the framing covered by Builder's Risk) from the contractor to the insurer. The insurer expects to pay claims out of pooled premiums.
- Bonds: A three-party agreement (Surety, Contractor/Principal, Owner/Obligee). A bond is a guarantee of performance, not insurance against accidents. The Surety guarantees the Owner that the Contractor will finish the job. If the Contractor defaults, the Surety pays the Owner, but the Surety has the legal right to sue the Contractor to recover every penny (indemnification). The Surety expects exactly zero losses.
Contingencies
Contingency
An allowance added to an estimate for unknown risks and uncertainties inherent in the construction process. It is strictly not intended to cover changes in the project scope initiated by the owner; owner-directed scope changes are handled via formal Change Orders.
The Role of Contingencies
A contingency is a specific financial amount added to an estimate to cover unforeseen events, inherent risks, or anticipated errors in estimating that are highly likely to occur but cannot be precisely predicted in advance.
Contingency Percentages by Estimate Type
- Conceptual Estimates: 15% to 25% contingency (high uncertainty, vague scope).
- Preliminary Estimates: 10% to 15% contingency (systems defined, exact quantities still unknown).
- Detailed (Bid) Estimates: 5% to 10% contingency (low uncertainty, based on complete, stamped plans).
Quantitative Risk Analysis for Contingency
Advanced Contingency Determination
While a flat or contingency is common on small projects, large-scale civil engineering estimates demand a more rigorous, mathematical approach to determining the appropriate contingency fund.
Quantitative Risk Analysis Techniques
- Expected Monetary Value (EMV): A statistical technique that calculates the average outcome of future scenarios that may or may not happen (e.g., severe weather delays). It is calculated by multiplying the probability of a risk occurring by its financial impact (Probability Impact).
- Monte Carlo Simulation: An advanced probabilistic analysis used on mega-projects. An estimator assigns a probability distribution (e.g., a bell curve from to ) to every volatile line item in the estimate (like labor productivity or steel prices). Software then runs thousands of randomized simulations to output a probability curve of the final project cost.
- P-Values (Confidence Levels): Using Monte Carlo results, management can select a specific confidence level for the final budget. For example, a "P80" budget means the estimate has an statistical probability of not being exceeded, requiring a larger contingency than a "P50" budget (which is simply a coin flip).
Profit and Final Bid Price
Understanding Profit
Profit is the direct financial return a contractor earns for taking on the significant financial and operational risk of the project, managing the complex logistics, and providing their specialized expertise. It is the reward for successful, efficient execution.
Profit margins vary widely depending on the local market conditions, the level of competition for the bid, the project size, and the perceived risk level. Typically, targeted profit ranges from 2% to 15% of the total estimated cost (direct + indirect + contingency).
The Final Bid Price Calculation
Sequential Order of Operations
The final bid calculation follows a strict sequential order of operations to ensure all costs and markups are applied accurately.
Total Cost Calculation
Calculates the total cost by summing direct costs and all overheads.
Variables
| Symbol | Description | Unit |
|---|---|---|
| Total Cost | - | |
| Total Direct Cost (Materials + Labor + Equipment + Subcontractors) | - | |
| Project Overhead (General Conditions) | - | |
| General Overhead (Home Office Overhead) | - |
Estimated Cost Calculation
Calculates the estimated cost by adding contingency to the total cost.
Variables
| Symbol | Description | Unit |
|---|---|---|
| Estimated Cost | - | |
| Total Cost (Direct + Indirects) | - | |
| Contingency Allowance | - |
Final Bid Price Calculation
Calculates the final bid price by adding the desired profit to the estimated cost.
Variables
| Symbol | Description | Unit |
|---|---|---|
| Final Bid Price | - | |
| Estimated Cost (including contingency) | - | |
| Profit Margin Amount | - |
- Indirect costs are absolutely necessary for project completion but cannot be assigned directly to specific physical tasks. Omitting them will cause the contractor to lose money.
- Project Overhead (General Conditions) is site-specific and covers supervision, temporary facilities, and permits.
- General Overhead covers home office administrative expenses and must be distributed across all company projects.
- Contingencies account for known risks (like unpredictable weather or minor estimating omissions).
- They are not "slush funds" for owner scope changes.
- The contingency percentage should drop as the design progresses and the "Cone of Uncertainty" narrows.
- Profit is the contractor's financial reward for assuming risk and executing the project efficiently.
- Profit is typically calculated as a percentage of the total estimated cost (which includes direct costs, indirects, and contingency), not just the direct costs.
- The final bid price represents the cumulative total of all calculated expenses plus the profit margin.