The Contingency Line: Why Envelope Budgets Need Room for the Unknown

A strata council presents a restoration budget to the owners. The number is the contractor’s contract price, and there is no contingency line, because adding one felt like padding and the council wanted the levy to be as small as possible.

Everybody in the room with construction experience knows that project will exceed its budget. The only question is when the council will have to come back and ask for more.

This is not a failure of estimating. It is the nature of envelope work, and the way to manage it is to acknowledge it in the budget rather than discover it mid-project.

Why the number cannot be known in advance

Nobody can see behind cladding until it comes off. Nobody can see the condition of a substrate under a membrane until the membrane is removed. Nobody can measure the full extent of delaminated concrete until chipping starts.

A condition survey estimates hidden damage from what is visible, from sampling at test openings, and from techniques like delamination sounding and cover testing. Those methods are genuinely useful and they narrow the range considerably, which is why the survey described in the post on building envelope condition assessment is worth doing properly.

But an estimate built from sampling is still an estimate. Deterioration is not uniform. Water follows paths nobody predicted. A building can have three areas of hidden damage in places the survey happened not to open.

So the real choice is not between a budget with uncertainty and a budget without it. It is between a budget that acknowledges the uncertainty and one that pretends it away.

Three different tools, often confused

An allowance is money carried for a specific item whose existence is known but whose quantity is uncertain. Concrete repair estimated at a given area is the classic example. The survey says the building probably needs roughly this much, and the budget carries that figure knowing the real number will differ.

A unit price is the agreed per-unit rate for that work, established before the contract begins. This is the mechanism that protects a strata financially, and it is the one most often left out.

Here is why it matters. When the actual quantity of concrete repair turns out to be higher than the allowance assumed, that additional work has to be priced. If a unit price was agreed during the tender, it bills at a rate the strata accepted when contractors were competing for the job. If no unit price was agreed, it gets negotiated mid-project, when the building is opened up, the access is installed, the schedule is running, and the strata has essentially no leverage. That environment is described in the post on envelope tender scope of work, and it is where budgets go badly wrong.

A contingency covers genuinely unforeseen conditions that nobody anticipated at all. Not more of a known item, but something that was not in the picture: an assembly built differently than the drawings show, a structural condition requiring engineering input, or damage in a location the survey had no reason to examine.

A sound budget uses all three. Allowances with unit prices for the known unknowns, and a contingency for the rest.

Sizing it

There is no single correct percentage, because the right figure depends on how much uncertainty a specific project carries.

Less uncertainty, and therefore a smaller contingency, comes from: a recent thorough condition survey with multiple test openings; a building with good records and known construction; recent related work that already exposed parts of the assembly; and a well-defined scope with clear acceptance criteria.

More uncertainty, and a larger contingency, comes from: an older building with limited or missing documentation; a history of leaks with unknown extent; assemblies that cannot be inspected without opening them; previous repairs of unknown quality; and any project where the survey was constrained by access or budget.

The consultant who did the survey is best placed to recommend the figure, and the important part is that they explain what it covers. A contingency justified as standard practice is a number. A contingency justified by naming the specific unknowns it addresses is a plan, and the council can ask whether more investigation would reduce it.

That trade-off is worth making explicitly. More sampling and more test openings cost money up front and narrow the uncertainty, which allows a smaller contingency. The comparison is between paying to know and setting aside more to cover not knowing. On a large project, paying to know usually wins.

Getting the funding resolution right

This is where the practical damage happens on strata projects.

Where a project is funded by a special levy, the resolution authorizing that levy sets the amount. If it authorizes only the base contract price, there is no legal room for the additional work the project will uncover. When the extra work appears, the strata has to hold another meeting and pass another resolution while the building sits opened up and the crew waits.

That delay is expensive in itself, and it puts the council in the position of asking owners for more money in the middle of a project that already looks like it is going wrong, which is not where anyone wants to be.

The resolution should authorize an amount that includes the contingency, and its wording should address how funds may be used and what happens to any surplus. The mechanics of levy versus reserve funding are set out in the guides on contingency reserve fund versus special levy and special levy versus strata loan.

It is worth having the resolution wording reviewed before it goes to the owners. A resolution that has to be redone mid-project costs far more than the review.

Controlling how it gets spent

A contingency without a spending process is a slush fund, and that is the legitimate concern behind council reluctance to include one. The answer is process, not omission.

Define who approves draws before work starts. A common arrangement gives the consultant authority to approve items below a stated threshold so routine discoveries do not stop the job, with anything above that going to the council. The threshold should be low enough to keep the council informed and high enough that work is not held up waiting for a meeting.

Require documentation for every draw: what was found, why it was not foreseeable, what the proposed remedy is, and what it costs against the agreed unit prices where applicable.

Report contingency status at every project update, showing what has been drawn, for what, and what remains. Councils that see this weekly are far calmer than councils who learn about it at the end.

Verify before approving. The consultant should confirm that a claimed unforeseen condition genuinely is one, and not work that was already within the contracted scope. This is a substantial part of what the independent consultant role, described in the post on envelope engineer versus contractor roles, is actually for.

The money that is not spent

Unspent contingency stays with the strata. It is not part of the contractor’s price and they have no claim on it.

Where the project was funded from the contingency reserve fund, unspent money simply remains in the fund. Where it was funded by special levy, the treatment of surplus funds is governed by the resolution and the applicable legislation, which is another reason the resolution wording matters.

Worth saying to owners at the outset: the contingency is an authorization to spend, and some or all of it may never be spent. Framing it that way makes it considerably easier to get approved than presenting it as an additional expense.

What no contingency actually costs

A project without one does not spend less. It runs out of money.

At that point the work stops or continues into an unfunded overrun. The council calls a meeting. Owners who approved a number are asked for more, having been told the first number was the number. Trust erodes. The building sits opened up, which on an envelope project can mean exposed assemblies during a rainy season.

Meanwhile the additional work still gets priced, and it gets priced in the worst possible negotiating position.

Everything about that outcome is worse than including a properly justified contingency at the start and explaining it honestly to owners. The uncertainty exists either way. The only variable is whether it was planned for.

The short checklist

Get a condition survey thorough enough to narrow the range, and treat additional investigation as a way to reduce the contingency rather than as an extra cost.

Carry allowances with agreed unit prices for the known unknowns, particularly concrete repair and substrate repair.

Carry a contingency for genuine unforeseen conditions, sized against the specific uncertainties of the building and explained in those terms.

Write the funding resolution to cover the total including contingency, with clear wording on use and surplus.

Define the approval process, the documentation requirement, and the reporting cadence before work begins.

Tell owners plainly what the contingency is for and that unspent funds stay with the strata.

None of this makes the project cheaper. It makes the final number close to the number the owners approved, and on a strata project that is usually what matters most.

Sources and further reading

• Strata Property Act (British Columbia), special levy and contingency reserve fund provisions, referenced 2026
• Canadian Construction Documents Committee, CCDC 2 Stipulated Price Contract, change order provisions, referenced 2026
• BC Housing, Building Enclosure Renewal Guide, project budgeting considerations, referenced 2026
• Real Estate Institute of British Columbia, depreciation report guidance, referenced 2026
• Allweathercoating project cost records, Metro Vancouver, 2026