Cost Overruns in Canadian Construction: How Feasibility Studies Reduce Risk
What the evidence says about why Canadian projects run over budget, and how early financial analysis, honest contingency, stress tests and cost-to-complete tracking turn surprises into managed risks.
1. Why Overruns Keep Happening
Most overruns are not a surprise to people who look for them. A project is approved on an early estimate prepared before the design is settled, the site is fully understood or the market has finished moving. Then the design changes, the ground turns out differently, prices rise, and the original number becomes a memory.
The financial effect is rarely proportional. A cost increase can wipe out a project's margin, force the owner to inject more equity and strain lender covenants at the same time. A small percentage overrun on a thin-margin project can mean a large percentage drop in profit.
That is why a feasibility study belongs at the start. It does not predict the future; it tests how much of the future the project can survive. Our business planning and financial modeling work applies that thinking to construction budgets, funding plans and downside cases.
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2. What the Evidence Shows
The best recent Canadian data comes from HKA's sixth annual CRUX Insight report, published in October 2023, which covered more than 1,800 capital projects in 106 countries, including 99 in Canada. It measures disputes and delays rather than every overrun, but the causes it identifies are the same ones behind most budget blowouts.
Top Causes of Claims on Canadian Projects (Share of Projects Affected)
Source: HKA, CRUX Insight 2023 ("Forewarned is Forearmed"), Canadian sample of 99 projects, as reported by Construction Canada (October 2023). Bars scaled to the largest value.
An earlier EY study of Canadian power and utility megaprojects, reported in 2017, found an average cost overrun of 39% and an average delay of about 12 months. It covers large utility projects and is dated, so it should be read as an indication of scale, not a forecast for a typical commercial build. The HKA report describes these causes as often predictable and avoidable, which is exactly where a feasibility study earns its keep.
3. A Cautionary Case: Muskrat Falls
The Muskrat Falls hydroelectric project in Newfoundland and Labrador is a widely cited Canadian example. Reporting from a 2019 public inquiry said the project's cost had essentially doubled, to more than $12.7 billion since its 2012 sanction. A forensic audit presented at the inquiry found several feasibility-stage lessons:
- Contingency disappeared early: the auditor testified that executives knew within months that contingency was basically exhausted, yet the audit found no evidence that cost estimates were adjusted before a federal loan guarantee was finalized.
- Bids and estimates diverged: bids ranged from 60% to 160% above the owner's estimates, a signal that the estimate was not reliable.
- Procurement risk: one major contractor was chosen largely on a low bid, and was reported to have missed performance targets for roughly two years before replacement was examined.
- Ignored warnings: a risk assessment that added a possible $2.4 billion to the risk calculations was reportedly not reviewed by executives.
Muskrat Falls is a megaproject, and a small clinic or warehouse is not. But the pattern applies at every scale: weak early estimates, thin contingency, low-bid procurement and warnings that nobody acts on.
4. Where Overruns Come From
| Source of overrun | What happens | Feasibility-stage control |
|---|---|---|
| Scope change | Owner or user requests additions after budget approval | Fix a clear scope; set a change-approval process and a funded allowance |
| Design problems | Incomplete or incorrect drawings create rework and claims | Advance design before committing; independent design review |
| Site conditions | Soil, contamination or servicing surprises | Geotechnical and environmental reports; site contingency |
| Optimistic estimate | Early cost based on best-case assumptions | Estimate ranges, comparable projects, independent check |
| Price escalation | Materials and labour cost more by the time of purchase | Escalation allowance; early purchase of critical items |
| Procurement | Lowest bid leads to claims or underperformance | Qualification criteria; contract risk allocation |
| Schedule delay | Approvals and delays add carrying cost | Schedule buffer; interest reserve; approval timeline in the model |
| Weak governance | Warnings ignored; no authority to stop | Defined decision rights and reporting triggers |
5. Estimate Accuracy and Design Maturity
The earlier in a project you estimate, the wider the likely error. Cost consultants group estimates into classes by how much of the design is defined. The ranges below are commonly cited illustrations; exact figures vary by source, industry and project, so use them to understand the shape, not as a guarantee.
| Estimate class | Design defined | Typical use | Illustrative accuracy range |
|---|---|---|---|
| Class 5 | 0% to 2% | Early screening, order of magnitude | −50% to +100% |
| Class 4 | 1% to 15% | Feasibility studies, comparing options | −30% to +50% |
| Class 3 | 10% to 40% | Budget approval and funding | −20% to +30% |
| Class 2 | 30% to 70% | Tender pricing | −15% to +20% |
| Class 1 | Near complete | Final cost control | −3% to +15% |
Illustrative Width of the Uncertainty Band by Estimate Class
Calculated from the illustrative ranges in the table above (high end minus low end). Sources differ on exact ranges; treat this as a picture of how uncertainty narrows, not as a standard.
The lesson: a feasibility-stage estimate is not a price. It is a range, and the study's job is to show whether the project works across that range, not just at the midpoint.
6. How a Feasibility Study Reduces Risk
| Feasibility activity | Risk it addresses | Result |
|---|---|---|
| Define scope and requirements | Scope creep | Clear baseline and change rules |
| Site and technical review | Unforeseen conditions, approvals | Known constraints priced in |
| Build the budget line by line | Optimistic estimates | Traceable, challengeable numbers |
| Add contingency and escalation | Unknowns and price change | Funded cushion |
| Model financing and cash flow | Interest, draw timing, equity gaps | Realistic funding plan |
| Stress-test costs and revenue | Margin collapse | Break points identified |
| Set go, no-go or revise rules | Optimism bias, sunk-cost thinking | Decision discipline |
For a step-by-step method, see our guide on healthcare services business plans in Canada, which walks through a break-even model, startup budget and facility planning for a clinic, one of the most common small-scale build-outs.
7. Contingency and Escalation
- Match contingency to maturity: an early estimate with little design warrants more contingency than a nearly complete design.
- Separate contingency from escalation: contingency covers unknowns in scope and site; escalation covers price change over time.
- Track the drawdown: Muskrat Falls shows what happens when contingency is exhausted early and nobody changes the forecast.
- Escalation varies: Turner & Townsend notes escalation may differ by project size, procurement route and province, and cites tariffs and labour constraints as risk drivers.
8. Stress Testing: A Worked Example
The numbers below are hypothetical and round. They show how a modest overrun can erase profit on a project with a healthy-looking margin. Lender guidance commonly suggests testing cost increases of around 10% to 15%.
| Scenario (hypothetical project) | Total cost | Revenue | Profit |
|---|---|---|---|
| Base case | $10,000,000 | $11,500,000 | $1,500,000 |
| Cost overrun +10% | $11,000,000 | $11,500,000 | $500,000 |
| Cost overrun +15% | $11,500,000 | $11,500,000 | $0 |
| Cost +10% and revenue −5% | $11,000,000 | $10,925,000 | −$75,000 |
Hypothetical Profit Under Stress ($ Thousands)
Hypothetical project. A 10% cost increase cut profit by two-thirds, and a 15% increase eliminated it. The final bar is a small loss and is shown at minimum width.
The takeaway is the leverage. When margin is about 13% of revenue, a 10% cost overrun consumes two-thirds of profit. A feasibility study finds this out on paper, when the owner can still renegotiate scope, price, funding or decline to proceed.
9. Procurement and Change Control
- Be wary of the lowest bid: if bids come in far above or below your estimate, investigate before choosing; both can signal a scope or estimate problem.
- Allocate risk deliberately: understand who carries site, design and price risk under each contract type, and price it.
- Control change: require written, priced change orders approved before work proceeds.
- Hold back and secure: holdbacks, bonds or security protect against non-performance.
- Act on warnings: set triggers, such as a defined percentage of contingency used, that force a review.
10. Tracking Costs During Construction
A feasibility study sets the baseline; accounting tells you how you are performing against it. Good job costing depends on accurate, timely bookkeeping. Our guide on double-entry bookkeeping for SMEs explains the ledger structure behind cost tracking, and bookkeeping experts describe the common small business mistakes, such as miscoded costs and unreconciled accounts, that can hide an overrun until it is too late.
| Report | Frequency | Question it answers |
|---|---|---|
| Budget versus actual by cost code | Monthly | Where are we over or under? |
| Committed costs report | Monthly | What have we promised but not yet paid? |
| Cost-to-complete forecast | Monthly and at each draw | Will the remaining budget finish the job? |
| Contingency drawdown | Monthly | How much cushion is left, and how much work remains? |
| Change order log | As changes occur | What has scope growth cost? |
| Cash flow forecast | Rolling | Will funding cover the next draws? |
If you want finance support for this reporting, our fractional CFO onboarding checklist lists what to prepare, and our CFO advisory services can build the reporting and review it with you.
11. What Lenders Look For
Lenders monitor overrun risk directly. Published lender guidance describes quantity surveyors who verify that the budget is reasonable and that each draw matches progress, and a cost-to-complete test at each draw. If overruns appear, a lender may require additional equity before releasing more funds. Typical loan-to-cost ratios of about 60% to 80%, equity of roughly 20% to 40% and a funded interest reserve all come from the feasibility model.
- Financial statements: lenders may ask for professionally prepared statements; see our guides on the compilation engagement process and transitioning to compilation from review.
- Complex structures: project companies, joint ventures and related-party arrangements may call for our specialized services.
- Ongoing records: bookkeeping, payroll and tax filings are part of our core accounting and tax services.
12. Risk Management: Financial Risk and Business Risk
Overrun planning is risk management. Financial risk is the effect of cost, price and interest changes on cash and profit. Business risk is the threat to the project's delivery, relationships and reputation.
| Risk | Type | Control |
|---|---|---|
| Estimate too optimistic | Financial risk | Ranges, comparables, independent review |
| Contingency used up early | Financial risk | Drawdown tracking with review triggers |
| Price escalation and tariffs | Financial risk | Escalation allowance; early purchase of critical items |
| Equity call from a lender | Financial risk | Reserve for overruns; conservative leverage |
| Scope creep and design errors | Business risk | Clear scope; change control; design review |
| Contractor underperformance | Business risk | Qualification, security, oversight |
| Schedule delay and approval risk | Business risk | Buffers; staged commitments |
| Warnings ignored | Business risk | Defined decision rights; reporting triggers |
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13. Feasibility Checklist
- Scope written down, with a process and budget for changes.
- Site, zoning, servicing, geotechnical and environmental findings reviewed.
- Budget built line by line, with the estimate class and its likely range stated.
- Contingency and escalation shown separately and matched to design maturity.
- Financing, interest reserve and equity requirement modelled.
- Cost and revenue sensitivities of at least 10% to 15% tested.
- Procurement approach and risk allocation decided.
- Monthly budget-versus-actual and cost-to-complete reports planned.
- Triggers and decision rules for escalation, pause or exit agreed.
- Records and bookkeeping set up for job costing.
14. Frequently Asked Questions
What causes cost overruns in Canadian construction?
Common causes include changes in scope, incorrect or incomplete design, unforeseen physical conditions, workmanship problems, optimistic early estimates, inadequate contingency, price escalation and weak procurement or oversight. A 2023 report covering 99 Canadian projects found change in scope was the leading cause of claims, affecting 32.7% of projects, followed by incorrect design at 26.5%.
How does a feasibility study reduce construction cost overruns?
It tests the project before money is committed. It clarifies scope, checks the site and approvals, builds a cost estimate with realistic contingency and escalation, stress-tests the budget with higher costs and lower revenue, and sets decision rules. It cannot eliminate risk, but it exposes weak assumptions while changes are still cheap.
How much contingency should a construction project include?
Published lender guidance commonly cites at least 5% to 10% of hard construction costs, with more for complex sites or early-stage designs. The right figure depends on design completeness, site risk, procurement method and market conditions, so confirm it with a cost consultant and your lender.
How accurate is an early construction cost estimate?
Early estimates are inherently wide. Commonly cited estimate classes show feasibility-stage estimates with ranges on the order of minus 30% to plus 50%, narrowing as design matures, though exact ranges vary by source and industry. That is why feasibility studies use contingency and sensitivity tests rather than a single number.
What is a cost-to-complete analysis?
It compares money already spent and committed with the forecast cost of finishing the project, and checks that the remaining budget and funding are enough. Lenders often run it at each draw, and if overruns appear they may require additional equity before releasing more funds.
15. Final Thoughts
Overruns are not bad luck; they are the predictable result of early numbers that were treated as final. A feasibility study turns those numbers into ranges, adds honest contingency, tests the downside and sets rules for what happens when warnings appear. It is risk management applied before the first shovel: understand the financial risk in the budget and the business risk in the plan, and decide with eyes open whether the project can survive being wrong.
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