What Are Liquidated Damages in Construction? How a Late-Finish Clause Works

By Erik Tishenko, Modern Northwest · Published November 4, 2026

Liquidated damages are a daily amount, set in the construction contract, that the contractor owes the owner for each day the job finishes late. Instead of proving the actual cost of the delay after the fact, both sides agree on a number up front. Courts generally enforce them only when the real loss was hard to measure at signing and the daily amount was a reasonable forecast of it, not a penalty. The clock usually runs from the contract completion date until substantial completion.

How a typical late-finish clause fits together. Your contract sets each piece. This is a plain-language guide from a contractor, not legal advice.

Working to a hard opening date? We plan the finish backward from your move-in date. Licensed in Oregon (CCB #198582) and registered in Washington (L&I MODERNI888R7). Call (360) 326-2747.

Why owners use them

A late commercial job costs the owner money that is hard to pin down: rent on a space that cannot open, a lease on the old space that has to be extended, lost sales, staff already hired. Proving each of those after the fact is slow and uncertain. Liquidated damages settle it in advance: if the job is late, the contractor owes the agreed amount per day, and the owner does not have to prove the actual loss.

When they hold up, and when they do not

The legal sources we checked agree on the test. A liquidated damages clause is generally enforced when:

• The real loss was hard to measure when the contract was signed.
• The daily amount was a reasonable forecast of that loss, judged as of signing, not with hindsight.
• It works as compensation, not punishment. A number meant to scare the contractor into finishing is a penalty.

Courts have thrown out daily rates with no real basis. In a Texas case, a city lost its claim because it had no study or analysis behind its daily rate, which the court suggested was chosen at random. In a Pennsylvania case, a rate copied from the city's past projects, with no math for the job at hand, was struck even though the city said its real losses were higher. The safest rates are built from the owner's actual expected costs of a late opening, written down when the contract is drafted.

What starts and stops the clock

The daily amount usually starts the day after the contract's date for substantial completion and stops when the job reaches it: the point when the owner can occupy and use the space, even with a punch list open. Some contracts run the clock to final completion instead, and courts have enforced that when the contract says so plainly, so read which date yours uses.

Delays the contractor did not cause move the date. Under the standard AIA general conditions, the contract time can be extended by change order for delays such as changes the owner orders, and an owner who caused the delay generally cannot charge for those days. The clock often starts with a notice to proceed. A late permit, an owner decision that held up the work or an owner-requested change are the usual arguments. That is why documenting delays as they happen matters to both sides.

For owners: setting a fair number

• Build it from your real costs. Rent, extended rent on the old space, carrying costs, lost revenue estimates. Write down how you got there.
• Set a realistic completion date. A tight date with heavy liquidated damages raises bids. Our commercial construction timeline covers how long the pieces really take, permits included.
• Decide early. Late owner decisions are a common reason contractors get time extensions.
• Consider a cap. A cap limits the contractor's exposure and can keep bids lower.

For everyone: the schedule is the real protection

Liquidated damages are a backstop, not a plan. The jobs that open on time are the ones planned backward from the opening date, with the permit, long-lead materials and owner decisions scheduled from the start. Our Sit Still Salon job in Salmon Creek opened its 700 square feet after a fall 2024 build, and Thirsty Caterpillar in Lake Oswego, 3,790 square feet of books and coffee, wrapped in May 2026. Related terms are in our commercial construction glossary.

Frequently asked questions

The bottom line

Liquidated damages trade proving the real cost of a late finish for an agreed daily amount. They hold up when the amount was a reasonable estimate at signing, they usually stop at substantial completion, and they move when the owner causes the delay. Set the number from real costs, and put the effort into the schedule.

Modern Northwest has built commercial space across Portland and Southwest Washington since 2005. Tell us your opening date.