How to Read a GMP Contract: Open-Book Ledgers, Contingency Lines, and Fee Structures

A Guaranteed Maximum Price (GMP) contract is standard on large commercial, healthcare, and complex institutional construction projects. It gives owners budget certainty through a defined ceiling while keeping the books open so you can see every dollar the GC spends.

Most owners sign GMP contracts without fully understanding the structure. They know there's a ceiling, they understand there's a GC fee, and they trust that the rest will work out. That trust is usually fine when the GC operates transparently. But when it doesn't, the owner often doesn't discover the problem until they're arguing over contingency draws at month six.

This post walks you through a GMP contract's six critical sections — what each one means, what the right structure looks like, and the red flags that should prompt renegotiation before you sign.

1. The GMP Amount: Your Budget Ceiling

The GMP amount is the maximum the owner will pay for the project. If the GC's costs exceed the GMP, the GC absorbs the overage. That's the guarantee.

The GMP is typically established at the end of the preconstruction phase — after design development drawings are complete, subcontractor bids have been received, and the GC has a solid basis for estimating costs with confidence. A GMP set too early in the design process (at schematic design or early design development) will be heavily loaded with contingency because the GC doesn't have enough information to price confidently.

What to look for: The GMP exhibit in your contract should include a cost breakdown showing what's inside the GMP: subcontractor costs, general conditions, GC fee, owner contingency, and GC contingency. Each of these should be a separate, visible line item — not rolled into a single number.

Red flag: A GMP that's a single number with no breakdown. You can't manage a budget you can't see.

2. GC Fee: Percentage of Cost

The GC fee is the GC's profit on the project. On large commercial and healthcare construction, the fee is typically 3-8% of actual project costs. On smaller commercial projects, it may be higher. The fee is earned as costs are incurred — the GC bills their fee as a percentage of each monthly pay application.

Fee structure options:

• Percentage of cost: GC earns X% of every dollar spent. This creates a perverse incentive — the more costs run, the more fee the GC earns. It's the standard structure, but owners should be aware of the incentive it creates.
• Fixed fee: GC earns a fixed dollar amount regardless of total cost. This aligns GC incentives with cost control — if costs run low, the GC's percentage return improves, not their total dollars. Fixed fee is better for the owner but requires more negotiation.

What to look for: The fee should be defined as a percentage of "cost of the work" (subcontractor costs and direct materials) — not of the GMP total including contingency. If the GC earns fee on the contingency draw, they have an incentive to spend contingency.

Red flag: Fee calculated as a percentage of GMP rather than actual cost. It means the GC earns fee on contingency that may never be spent — and if it is spent, they earn fee on that too.

3. General Conditions: Fixed or Percentage

General conditions are the costs the GC incurs to manage the project: the superintendent's salary, the project manager's time, the project trailer, safety program administration, temporary utilities, site logistics, and insurance. These are real costs — they should be transparent and controllable.

Fixed vs. percentage: General conditions should be a fixed line item, not a percentage of costs. A fixed general conditions line means the owner knows exactly what they're paying for project management from month one. A percentage-based general conditions line means as costs increase, the general conditions payment increases — even if the management work doesn't.

What to look for: A general conditions exhibit that lists each cost category with the associated monthly or project-total amount: superintendent at $X/month, PM at Y% time at $Z/month, trailer at $X/month, temporary utilities at $X/month, safety program at $X/month.

Red flag: General conditions listed as a percentage of project costs (e.g., 8% of cost). This means you're paying more for management as costs go up — an incentive structure that works against owner cost control.

4. Contingency: Owner's and GC's — Separate Pools

Contingency is a reserve of funds set aside to cover unforeseen costs. In a properly structured GMP contract, there are two separate contingency pools:

GC contingency: Funds the GC controls to cover unforeseen conditions they discover during construction — scope gaps in the drawings, coordination issues, weather delays, minor design errors. The GC can draw from their contingency without owner approval. When the GC contingency is exhausted, the GC absorbs additional costs up to the GMP. The GC does not earn fee on contingency draws.

Owner contingency: Funds the owner controls to cover owner-initiated changes, design errors by the architect or engineer, and true unforeseen conditions (underground utilities, soil conditions different from the geotechnical report). The owner approves every draw from their contingency. Owner contingency draws are billed at cost plus GC fee.

What to look for: Two clearly labeled contingency pools, each with a defined amount and defined draw protocol. The GC's contingency should be visible in the cost breakdown but identified as a separate line that the GC manages. The owner's contingency should require written owner approval before any draw.

Red flag: A single contingency pool that the GC can draw from for any cost overrun. This means the GC can spend your contingency on their scope gaps without your approval, and you don't know the contingency is gone until it's gone.

5. Open-Book Costs: Every Invoice Submitted for Review

Open-book means the GC submits documentation for every cost they bill to the project: subcontractor pay applications, material receipts, labor cost reports, equipment invoices. The owner (or the owner's cost consultant) reviews these documents and verifies that what's being billed matches what was actually incurred.

This is the transparency mechanism that makes a GMP contract different from a black-box fixed-price contract. It allows the owner to verify that the GC is not inflating costs, billing for work not yet complete, or drawing from contingency for items that should be at the GC's risk.

What to look for: The contract should require the GC to maintain a cost ledger updated with every transaction, provide monthly cost reports by line item, and make all supporting documentation available for owner review within a specified turnaround (typically five business days).

What open-book actually requires from the owner: You need someone reviewing these documents. An owner who receives open-book reports but doesn't read them has the form of transparency without the function. On large projects, owners often retain an Owner's Representative (OR) or construction cost consultant to review GC pay applications. This is money well spent.

Red flag: Open-book provisions that require documentation "upon request" rather than on a defined monthly schedule. If you have to ask for the documentation, you won't always know to ask before there's a problem.

6. Savings Clause: How Savings Are Split

If the project's actual costs come in below the GMP, the difference is "savings." A savings clause defines what happens to those savings.

The three approaches:

• GC keeps savings: The GC earns the difference between the GMP and actual costs. No savings sharing. Common but unfavorable to the owner — it creates an incentive for the GC to pad the GMP and pocket the difference.
• Owner gets savings: All savings return to the owner. Gives the owner the full benefit of efficient construction, but reduces the GC's incentive to manage costs down once the GMP is set.
• Split savings (most common): Savings are shared 50/50, or at another agreed split (60% owner / 40% GC is also common). This aligns the GC's incentive with owner cost control — the GC shares in the benefit of coming in under budget.

What to look for: A savings-sharing clause with a defined split percentage. The clause should also define what "savings" means clearly: typically, the GMP minus actual costs minus unused owner contingency. (Unused GC contingency is the GC's to keep — that's how they're compensated for the risk of the guarantee.)

Red flag: No savings clause. If the contract is silent on savings, the GC typically keeps them by default. This is easily fixed in negotiation — ask for it.

Putting It Together

A well-structured GMP contract protects both parties. The GC knows their fee is defined, their contingency is theirs to manage, and their costs will be verified. The owner knows their budget ceiling is real, the books are open, and their contingency requires their approval.

The problems arise when one or more of these six elements is missing or structured poorly. A single contingency pool, percentage-based general conditions, and no savings clause together create a GMP contract that functions as a cost-plus agreement with a ceiling that the GC has already padded enough that they'll never hit it.

JK Prestige structures GMP contracts for hospital and large commercial projects with open-book cost ledgers, separate contingency pools, fixed general conditions, and savings-sharing clauses. The owner sees every dollar.

If you're reviewing a GMP contract for an upcoming project and want to walk through the specific language with someone who runs these contracts, a principal at JK Prestige answers directly.