Your project comes in 12 percent over budget, and everyone in the room is pointing at someone else. The architect says the design was fine. The builder says the design was incomplete. You are the one holding the invoices. Whether that overrun comes out of your pocket or your builder's was decided months before ground broke — the day you chose between hiring a general contractor and hiring a construction manager at risk.
Both roles put one firm in charge of building your project. But they are hired at different times, paid under different math, and carry different promises about the final number. A general contractor typically bids a fixed price on finished drawings and keeps whatever it saves. A construction manager at risk joins during design as your advisor, then guarantees a maximum price and opens its books to prove the costs are real. Here is how each model works, how the money moves, and which one fits your next project.
The Two Roles, Side by Side
A general contractor (GC) is the classic design-bid-build arrangement. You finish the design with your architect, put the drawings out to bid, and hire a GC — often the lowest qualified bidder — under a lump-sum contract. The GC holds the subcontracts, runs the site, and owns delivery of the finished building for the agreed price. If the work costs less than the bid, the GC keeps the difference. If it costs more, the GC absorbs it, unless you changed the scope.
A construction manager at risk (CMAR, sometimes written CM at-risk or CM/GC) is hired much earlier, usually on qualifications rather than price, while the design is still taking shape. In the first phase the CM acts as your consultant: estimating costs, flagging unbuildable details, and packaging the work for bidding. In the second phase the CM crosses the table and becomes the constructor, holding the trade contracts and guaranteeing the project will not exceed a guaranteed maximum price (GMP). The "at risk" part is literal — costs above the GMP come out of the CM's pocket, not yours.
The key distinction: a GC sells you a finished building for a price. A CMAR sells you a process plus a price ceiling, with the receipts to back it up.
The GMP: A Ceiling, Not a Price
The guaranteed maximum price is the heart of the CMAR model, and it is widely misunderstood. A GMP is not a fixed price. It is a cap on a cost-plus arrangement: you reimburse the CM's documented cost of the work plus an agreed fee, and the total cannot exceed the GMP unless the scope changes.
What goes into the number
A typical GMP has four layers:
- Cost of the work. The competitively bid trade contracts, materials, and equipment — the actual bricks, labor, and wiring. This is usually 80 to 90 percent of the GMP.
- General conditions. Site supervision, temporary facilities, safety, trailers, dumpsters, and project management staff. Often stated as a fixed lump sum inside the GMP so the CM cannot pad it.
- The CM's fee. A percentage of the cost of the work (commonly 2 to 5 percent on large projects) or a fixed sum, covering home-office overhead and profit.
- Contingency. An allowance for the unknowns inside the defined scope — a few percent held for surprises like concealed conditions or estimating gaps. Larger or riskier projects carry more.
Open books and buyout savings
Unlike a lump-sum bid, a GMP contract is open book: the owner can audit every trade contract, invoice, and payment application. When the CM bids out a trade package for less than the estimate carried in the GMP — a process called buyout — the savings stay inside the GMP, typically flowing to contingency or back to you, depending on the contract. Many GMP contracts include a shared-savings clause splitting leftover contingency between owner and CM at closeout, which keeps the CM motivated to buy well even though the savings are technically yours.
What happens when costs exceed the GMP
If the cost of the work plus the fee runs past the GMP without a change in scope, the CM absorbs the overrun. That is the risk it signed up for. But three things legitimately move the GMP upward, and you should expect each to arrive as a formal amendment:
- Owner-directed changes. You add scope, upgrade finishes, or revise the design — the GMP rises by the agreed cost of the change.
- Unforeseen conditions. Differing site conditions, code changes, or force-majeure events the contract assigns to you.
- Allowance overruns. Items priced as allowances in the GMP (fixtures you had not selected yet, for example) adjust to actual cost once chosen.
Everything else — a trade contractor defaulting, labor running long, materials costing more than estimated — is the CM's problem. That allocation is exactly why owners pay the CMAR premium: budget certainty in exchange for transparency.
Preconstruction Services: What You Buy Before Ground Breaks
The phase that sets CMAR apart happens before anyone pours concrete. While the architect is still drawing, the CM is already on your payroll providing preconstruction services:
- Progressive estimating. Cost opinions at schematic, design-development, and construction-document milestones — often around 30, 60, and 90 percent design — so the design stays tethered to the budget instead of arriving over it.
- Constructability review. A builder's eye on the drawings, catching details that cannot be built as drawn, sequencing conflicts, and missing coordination between trades.
- Value engineering. Structured proposals that cut cost without cutting function — a different structural system, an equivalent-but-cheaper finish, a simpler roof detail.
- Scheduling and phasing. A realistic master schedule, including whether parts of the project can start before the design is fully finished (fast-tracking).
- Bid packaging and procurement. Dividing the work into trade packages, prequalifying bidders, and running competitive buyouts.
Preconstruction is usually billed as a separate fixed fee or hourly-not-to-exceed amount, distinct from the construction-phase fee. That separation matters for your books: preconstruction fees are professional-service costs incurred during design, while the construction fee attaches to the building itself. If the project dies during design, you owe the preconstruction fee and walk away — there is no GMP yet and no construction obligation. Under design-bid-build, by contrast, you discover the project is over budget only when the bids come back, after you have paid for a full design.
Self-Performed Work: When Your Manager Also Swings a Hammer
Many CMAR firms have their own field crews, and they often want to perform some trade work themselves — concrete, carpentry, drywall, doors and hardware — rather than subcontracting all of it. This is self-performed work, and it is normal but needs guardrails, because the firm running the bidding is now bidding.
The standard controls, often written into law on public projects:
- Bid like everyone else. The CM submits its price for a trade package through the same competitive process as outside subcontractors, on the same documents and deadline.
- Best value wins. The owner must find that the CM's proposal offers the best value — not just the lowest number, but the right combination of price, schedule, and capability.
- Separate the fee. The CM's construction-management fee generally excludes profit on self-performed work; instead it earns a stated self-perform markup (often around 10 to 15 percent of that work's cost), disclosed in the contract. Without this rule the CM would earn a fee on its own fee.
- Owner approval. Self-perform packages typically require your explicit sign-off, and you can require the CM to step aside and bid the package openly if the numbers look soft.
Handled this way, self-perform can genuinely help: the CM's own crews answer to the same superintendent running the site, which tightens schedule control on critical-path trades. Handled loosely, it is the fox pricing the henhouse. Put the rules in the contract, not in a handshake.
How Each Model Hits Your Books
Here is where the delivery method stops being a construction decision and becomes an accounting one. The two models produce very different paper trails.
General contractor: one price, simple entries
A lump-sum GC contract is the simplest thing you can book. You have one contract value, monthly progress billings against a schedule of values, and retainage held back (typically 5 to 10 percent) until substantial completion. Your accounting questions are the classic contractor-side ones: how to recognize revenue or capitalize costs as the project progresses, how to carry retainage receivable and payable, and how to treat change orders as contract modifications. Make sure you understand the choice between percentage-of-completion and completed-contract revenue recognition before your first progress billing, because it decides which year your profit lands in.
CMAR: cost detail you must actually track
A GMP contract hands you far more data — every trade buyout, every general-conditions invoice, every contingency draw — and that data is only useful if your chart of accounts is ready for it. Three habits that pay off:
- Book preconstruction fees separately from construction costs. Preconstruction services arrive as professional-fee invoices during design; the construction phase arrives as cost-of-work reimbursements plus the CM fee. Mixing them into one "construction" bucket makes it impossible to answer the question every lender and auditor asks: what did the building cost versus the advice?
- Track GMP amendments as their own log. Each change order that moves the GMP is a contract modification with its own paper trail. Reconcile the amended GMP to cumulative billings every month, the same way you would reconcile any control account — the GMP is your budget baseline, and drift between the log and the pay applications is how overruns hide.
- Follow retainage down to the trades. Under CMAR the CM holds retainage from each trade contractor and you hold retainage from the CM. When a trade finishes early and its retainage is released, confirm the release flows through rather than sitting in the CM's account. Your GMP reconciliation should show retainage held at both levels.
Whichever model you choose, job-cost detail is the asset. A plain-text ledger where every draw, amendment, and retainage release is a timestamped, reviewable entry makes the open-book promise of a GMP contract real on your side of the table too — and the docs walk through structuring accounts for project-based tracking.
Which Delivery Method Fits Your Project?
There is no universally better option — only a better fit for your project's shape. Use this decision frame:
| Factor | Favors a general contractor | Favors a CM at risk |
|---|---|---|
| Design status | Complete, biddable drawings | Still evolving, or you want cost input during design |
| Schedule | Standard sequence: design, then bid, then build | Fast-track: start foundations while interiors are still being drawn |
| Price competition | Maximum — low-bid award, public procurement rules | Less direct — CM selected on qualifications, trades bid competitively |
| Budget certainty | Fixed price, but only as good as the drawings | GMP ceiling with open-book costs and auditable buyouts |
| Complexity | Straightforward, well-understood building types | Complex, phased, occupied-site, or technically demanding work |
| Owner involvement | Hands-off during construction | Hands-on — you review buyouts, contingencies, and self-perform bids |
| Fee premium | None — competition sets the price | Preconstruction fee plus CM fee, paying for early expertise |
Choose a GC when your design is complete, your scope is stable, and competitive bidding will squeeze the best price out of a straightforward project. Small commercial buildings, tenant improvements with finished drawings, and publicly funded work under low-bid statutes are classic GC territory.
Choose a CMAR when time matters more than squeezing the last dollar, the design needs a builder's input, or the project is too complex to price blind. Hospitals, schools, phased renovations of occupied buildings, and any project where starting six months earlier is worth a fee premium are where the model earns its keep.
Mistakes That Cost Owners Real Money
- Treating the GMP as a lump sum. A GMP caps reimbursable cost; it does not fix the price. If you never audit the cost of the work, never review buyouts, and never ask where the savings went, you paid CMAR fees for design-bid-build oversight. Exercise the open-book right or do not pay for it.
- Letting the CM self-perform without competition. Every self-perform package should face outside bids and your written approval, with the self-perform markup stated in the contract. Skipping this step turns your auditor into your vendor with no check on price.
- Signing a fuzzy savings clause. Decide before construction starts who keeps buyout savings and unused contingency — all to you, shared on a stated split, or held as additional CM contingency. The most expensive version of this conversation happens at closeout.
- Burying preconstruction fees in construction costs. If design-phase fees land in the same account as bricks and mortar, your project reporting overstates construction cost and understates soft costs, and your lender's draw review gets confusing. Separate accounts from the first invoice.
- Approving GMP amendments without updating the budget baseline. Every amendment moves the ceiling. If your internal budget still shows the original GMP three amendments later, your variance reports are fiction. Tie each amendment to a budget revision the same week it is signed.
Keep Your Project Costs Organized From Bid to Closeout
Whether you hire a general contractor on a fixed price or a construction manager under a GMP, the project generates hundreds of billings, amendments, and retainage releases that all need to land in the right account. Beancount.io provides plain-text accounting that gives you complete transparency and control over your financial data — no black boxes, no vendor lock-in. Get started for free and see why developers and finance professionals are switching to plain-text accounting.
