The Real Cost of Construction Delays: Calculating Interest Carry

Quick Answer: What is interest carry, and why does it quietly destroy more pro formas than cost overruns do? Interest carry is the ongoing interest expense on your construction loan for every day the project isn't generating revenue - and because it compounds daily and silently, a schedule slip that looks like "just three weeks" on a Gantt chart can erase more profit than a visible line-item cost overrun ever would.

Key Takeaways

• Compounding, Not Linear: Interest carry accrues daily against the full outstanding loan balance - a "small" schedule slip compounds into real money fast.

• Misaligned Incentives: A GC's contract rewards hitting substantial completion, not protecting your revenue timeline - the two aren't the same deadline.

• Carry-Aware Scheduling: Tracking the master schedule against the loan's carry rate, not just a wall-calendar date, catches slip in dollar terms before the next draw request reveals it.

Why Schedule Slippage Hits Harder Than Most Developers Model

Most underwriting models interest carry as a fixed assumption baked into the original timeline, not as a variable that grows every time the GC's schedule slips. A three-month delay on a $20M construction loan at a realistic carry rate isn't a rounding error - it's real six-figure money leaving the deal before a single unit is leased or a single tenant opens.

Why Standard GCs Don't Feel the Pain You're Feeling

A General Contractor's contract is typically structured around substantial completion, not your revenue timeline. Schedule slip is a GC's scheduling inconvenience; it's your capital bleeding out in daily interest. That asymmetry is exactly why schedule enforcement can't be left to the party with the least financial exposure to the delay - a risk we've documented in detail in The Myth of the Guaranteed Maximum Price Contract.

What Actually Drives the Delays That Drive the Carry

In our experience, the recurring culprits are the same across markets: subcontractor no-shows that go unescalated for weeks, permit and inspection cycles the GC didn't front-load into the schedule, and change orders that quietly extend the critical path without anyone recalculating the cost of the extension in interest-carry terms.

How an Owner's Rep Turns Schedule Enforcement Into Dollars Protected

JFD tracks the master schedule against the loan's carry rate, not just against a completion date on a wall calendar - so every week of potential slip gets flagged in dollar terms before it happens, not after the next draw request shows it. That reframing is often what gets a GC to actually prioritize the critical path instead of treating a slipped milestone as routine. It's the same active intervention we bring to a stalled site in Project Rescue: What to Do When Your Job Site Stalls.

A Simple Way to Model Your Own Exposure

Before signing a GC contract, run this back-of-envelope check: take your construction loan balance, multiply by your note rate, divide by 365, then multiply by the number of days a realistic worst-case schedule slip would add. On a $20M loan at a typical commercial construction rate, that works out to roughly $2,500-$4,000 in interest carry for every single day of delay, before counting lost revenue, extended insurance, or a stalled lease-up. Running that number before groundbreaking turns an abstract scheduling conversation into a figure the GC has to answer to.

Frequently Asked Questions (FAQ)

How is interest carry calculated on a construction loan?

As the outstanding loan balance multiplied by the interest rate, accrued daily over the construction period - so it grows both with time and with how much of the loan has been drawn.

What's a realistic interest carry exposure on a mid-size commercial project?

It varies widely by loan size and rate, but on a multi-million dollar commercial construction loan, each month of delay commonly represents tens of thousands of dollars in additional interest alone, before accounting for lost revenue.

Can interest carry risk be contractually shifted to the GC?

Partially, through liquidated damages clauses, but those rarely cover the full economic exposure - proactive schedule enforcement protects more capital than a damages clause collects after the fact.

Does value engineering help offset interest carry risk?

Only if it's genuine efficiency gains, not cost cutting - stripped-out quality that triggers rework usually adds delay and carry cost rather than reducing it.

When should a developer bring in an Owner's Rep to manage this risk?

Before the GC contract is signed - enforcing a realistic, carry-aware schedule from day one is far cheaper than rescuing a slipping one mid-build through our Owner's Representative services.

Call to Action: Have JFD review your master schedule and enforce your timeline. Talk to our Advisory Team today.