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Compare a company construction project's incremental investment with its expected business benefits. Build the cash-flow rows, discount them consistently and test whether the approval case survives a weaker benefit assumption.
Cost benefit analysis for a construction project compares the company's incremental investment with the business benefits it expects to receive. Measure both against a clear alternative, put them on the same timeline and calculate present values. A positive result is conditional on those assumptions, so the approval case must show what would change it.
Write a short decision statement: expand the distribution center's loading area or continue with existing operations. Continuing operations has costs and capacity limits; it is not automatically a zero-cost alternative. The appraisal includes only differences caused by choosing the expansion.
For each benefit, retain the baseline amount, proposed amount, evidence and accountable owner. Procurement can support avoided rental costs. Operations can support overtime changes. Sales and finance must support additional contribution after the variable costs needed to earn it.
The Lawrence Berkeley National Laboratory's economic-benefit methodology calculates net present value from changes in installed costs and operating savings, discounting the differences over time. The same arithmetic supports a company project case, using the company's own scope and assumptions.
This differs from construction unit cost analysis, which measures execution cost per completed quantity. A project can meet its construction budget while failing to produce the operating benefits used to approve it.
Start with the capital request, construction estimate, supplier quotes, operating-cost export and capacity assumptions. Give every row a project ID, scenario, category, amount, year or date, source reference and owner. Keep a separate flag for cash cost, cash benefit and unpriced consideration.
Use a common horizon and a stated timing convention. This example assumes investment at year zero and operating cash flows at each year-end. Finance supplies an illustrative nominal discount rate of 8%; all cash-flow amounts are nominal, pre-tax and exclude financing payments. This is an example assumption, not a recommended hurdle rate.
Present value = Cash flow in year t / (1 + Discount rate)^t
Net present value (NPV) = Present value of benefits - Present value of costs
Benefit-cost ratio = Present value of benefits / Present value of costs
The Department of Energy's commercial cost-effectiveness methodology discounts future savings and costs to present value and evaluates net savings. Its public and private ownership scenarios also illustrate why the financial basis must be explicit; a company should apply its approved assumptions.
An illustrative US distributor proposes a loading-area expansion. The table records the incremental costs and annual benefits against continuing current operations. Assume no residual proceeds within this four-year decision horizon; that assumption needs explicit review before a real approval.
| Input | Timing | Amount (USD) | Evidence to retain |
|---|---|---|---|
| Construction | Year 0 | 300,000 | Scoped supplier estimates |
| Design and permits | Year 0 | 40,000 | Approved estimate |
| Temporary operating disruption | Year 0 | 20,000 | Operating plan |
| Avoided overtime | Each year, 1-4 | 60,000 | Staffing comparison |
| Avoided outside rental | Each year, 1-4 | 50,000 | Rental baseline and termination assumptions |
| Additional contribution | Each year, 1-4 | 30,000 | Supported volume less variable costs |
| Added operating costs | Each year, 1-4 | 20,000 | Maintenance and utility assumptions |
Initial investment is 300,000 + 40,000 + 20,000 = $360,000. Annual gross benefits are 60,000 + 50,000 + 30,000 = $140,000; subtract $20,000 of added operating costs to get $120,000 of annual net benefit.
Place the discount rate in H1. In a separate schedule, columns A through E hold year, gross benefit, cost, net cash flow and discounted net cash flow.
| Year | Gross benefits (USD) | Costs (USD) | Net cash flow (USD) | Present value of net cash flow (USD) |
|---|---|---|---|---|
| 0 | 0 | 360,000 | -360,000 | -360,000.00 |
| 1 | 140,000 | 20,000 | 120,000 | 111,111.11 |
| 2 | 140,000 | 20,000 | 120,000 | 102,880.66 |
| 3 | 140,000 | 20,000 | 120,000 | 95,259.87 |
| 4 | 140,000 | 20,000 | 120,000 | 88,203.58 |
| Total | 560,000 | 440,000 | 120,000 | 37,455.22 |
Enter these spreadsheet formulas in the first data row and fill down:
D2=B2-C2
E2=D2/(1+$H$1)^A2
NPV_total=SUM(E2:E6)
Use separate labeled output cells for NPV and the ratio. The discounted annual net benefits total $397,455.22, leaving NPV of $37,455.22 after the initial investment. Display cents here for reconciliation; calculate with unrounded values.
Discount benefits and costs separately with =B2/(1+$H$1)^A2 and =C2/(1+$H$1)^A2. Sum each new column.
| Reconciliation | Present value (USD) |
|---|---|
| Gross benefits | 463,697.76 |
| Initial and operating costs | 426,242.54 |
| Benefits less costs | 37,455.22 |
The last row must equal the sum of discounted net cash flows. The benefit-cost ratio is 463,697.76 / 426,242.54 = 1.09, rounded to two decimals. Keep added operating costs in the denominator consistently; silently netting them against benefits changes the ratio's presentation.
Simple payback is 360,000 / 120,000 = 3 years, assuming benefits accrue evenly during each year. It ignores discounting and benefits after payback, so it supplements the present-value decision. Life cycle cost analysis handles the related choice between alternatives that deliver comparable service at different ownership costs.
Hold all inputs constant except additional annual contribution, reducing it from $30,000 to $15,000. Annual net benefit becomes 60,000 + 50,000 + 15,000 - 20,000 = $105,000. Its discounted total is $347,773.32, giving NPV of -$12,226.68.
The case crosses from positive to negative on that single assumption. Ask sales and operations to validate the demand and usable capacity behind it. Cost-benefit sensitivity analysis covers the wider process of testing assumptions without treating a single estimate as certain.
Bring a sample of your own project assumptions and operating-cost workbook to Covirage; it maps the columns, and its tools compute and check the supplied costs, benefits and timing. The external AI model explains the results with every figure traced to its rows. Create a free Covirage account and bring your investment case.
See project cost control for the supporting company workflow.
Include supportable changes relative to the alternative: avoided lease payments, lower operating expenses or additional contribution from capacity the company can use and sell. Record an owner and evidence for each assumption. Keep unpriced strategic benefits visible separately rather than inventing a dollar value.
It indicates that discounted benefits exceed discounted costs under the stated assumptions. Approval also depends on uncertainty, funding capacity, timing, required performance and alternatives. Compare net present value too, because a ratio alone does not show the total dollars the project is expected to add.
Finance should choose a consistent appraisal basis before calculation. This example uses pre-tax project cash flows without financing payments. A company's approval analysis may require a different basis, but its cash flows and discount rate must follow the same approved approach.