Cost-plus contracting with a GMP cap
A cost-plus GMP contract pays the builder the actual, documented cost of the work plus a stated fee — with a guaranteed maximum price capping what you can ever owe. Grandview writes and builds these contracts under a Utah DOPL B100 general contractor license for owners who want open-book transparency without an open-ended budget.
When a capped cost-plus contract is the right structure
Pure cost-plus is honest but unbounded: you pay whatever the work costs. A pure lump sum is bounded but opaque: the number is fixed, and so is the risk premium buried inside it. Cost-plus with a GMP cap takes the transparency of the first and the ceiling of the second. Below the cap, you pay actual cost plus fee and typically keep some or all of the savings. Above the cap, the overrun is ours.
It sits between two of its neighbors. In straight GMP contracting, the guaranteed number is the headline and the contract converts to it once design is settled; here, cost reimbursement is the operating mode for the whole job and the GMP is purely a backstop. In open-book CM at-risk, the same economics arrive wrapped in a full management engagement that starts in preconstruction. And if you’d rather hold the trade contracts yourself and pay us a management fee with no cap at all, that’s CM-as-agent.
The owners who choose this structure usually have an evolving scope — a custom home still making selections, a remodel with real unknowns behind the walls — and a hard number they cannot cross, often set by a construction loan. Utah lenders frequently ask for exactly this: open-book draws they can audit, under a maximum they can underwrite.
What “cost of the work” means — in writing
Most cost-plus disputes are definition disputes, so the definition does the heavy lifting. Before anything is signed, the contract spells out what is reimbursable: trade subcontract amounts, materials at invoiced cost with supplier backup, labor at stated rates, equipment rental, permits, and itemized general conditions like supervision and temporary facilities. It also spells out what is not — our overhead, our estimating time, and the cost of redoing work that failed inspection. Rework we cause is on our fee, not your reimbursables.
Every month you get an open-book pay application: actual invoices, lien waivers, labor records, and a running comparison of cost-to-date against the GMP. You have audit rights in the contract, not by courtesy. Our fee — fixed or a stated percentage — is a separate line you can see, and our license is a public record you can verify at dopl.utah.gov.
How the cap gets set — and what moves it
The GMP is built, not guessed: quantified takeoffs, real trade quotes, allowances for anything still undecided, and a stated contingency — all visible to you before you sign. On Wasatch Front lots we size that contingency around what the ground actually does here: expansive clay and collapsible soils that complicate footings, and 100-plus freeze-thaw days a year that constrain when concrete and flatwork can go in without winter-protection costs.
Once set, the cap moves only for owner-directed scope changes and genuinely concealed conditions — each priced as a written change order before the work proceeds. Estimating misses don’t move it; that’s what “guaranteed” means. We also specify to current Utah-adopted code from day one, because Utah’s updated I-codes took effect in July 2026 and pricing to the old edition is a quiet way contractors manufacture change orders later.
Then the incentives run your direction: below the cap, every competitive buyout and returned allowance is your money — shared or fully returned per the savings clause — instead of padding a lump sum.
What does a cost-plus GMP contract cost in Utah?
On Utah residential and light-commercial work, cost-plus fees commonly run 10–15% of the cost of the work, and the GMP typically carries a contingency of roughly 5–10% depending on how settled the design is. Treat both as ballpark planning numbers, not a promise — the fee and the cap are stated in writing before you commit.
What pushes the cap up: unfinished design (bigger allowances), difficult soils or steep bench lots, winter starts, and permitting in fast-growth cities like Lehi and Eagle Mountain where review timelines stretch general-conditions costs. What pulls it down: complete drawings, made selections, and a decisive owner — the fewer unknowns we’re guaranteeing against, the thinner the contingency needs to be.
Questions we actually get
What happens if costs blow past the GMP cap?
We absorb the overrun. That’s the deal: below the cap you pay actual cost plus fee; above it, completion is our obligation at our expense. The only exceptions are owner-directed scope changes and concealed conditions, both handled as written change orders you approve before the work happens.
Who keeps the savings if the job comes in under the cap?
Whatever the savings clause says — and we put it in the contract, not a handshake. Common structures return 100% of savings to the owner or split them at a stated ratio to reward efficient buyout. Either way, unused contingency and returned allowances are visible in the open-book reporting, so nothing quietly disappears.
Doesn’t a percentage fee reward you for spending more?
That’s the honest critique of uncapped cost-plus, and the cap is the answer: past the GMP, extra spending costs us, not you. If the incentive still bothers you, we’ll quote a fixed fee instead — the reimbursable structure works identically either way, and we offer both.
Can we start building before design is finished?
Yes — that’s a main reason this structure exists. Early scopes like excavation and foundations can proceed cost-plus while later scopes are still being drawn, with allowances holding their place under the cap. As selections land, allowances convert to real quotes and the reporting shows exactly how the cap is holding.
Where this fits in our management work
Cost-plus with a GMP cap is one contract structure within our construction management practice, part of Grandview’s broader planning and project management group. If you’re not sure which structure fits your project, tell us about it — we’ll recommend the right one, including the options that pay us less.
Tell us what you’re working on
We reply within a couple of hours during business hours — a day at most. You’ll get a straight read on scope, sequence, and budget before anyone commits to anything.