Florida business owners default to cost-plus construction contracts because they believe it gives them more control. The logic sounds right: you see every invoice, nothing is marked up without your visibility, and the GC isn't hiding profit in the bid price. The reality is different. Cost-plus shifts all financial risk to the owner, creates no incentive for the GC to control costs, and produces a final number that nobody can predict at the start.
Fixed-price commercial contracts — done correctly — do the opposite. The GC takes the scope risk. The owner knows the number before they sign. And if the scope doesn't change, the price doesn't change. This article explains why fixed-price is safer than cost-plus for most commercial fit-outs, what a Guaranteed Maximum Price (GMP) contract adds for larger projects, and how scope documentation is what makes a fixed-price contract work.
The Problem with Cost-Plus on Commercial Fit-Outs
A cost-plus contract pays the GC their actual costs — labor, materials, subcontractor invoices — plus a fee (typically 10–15% of cost, or a fixed fee). The total is not known until the project is complete.
Business owners choose cost-plus for two reasons:
- They believe it is transparent — they see the costs
- They believe the GC has no incentive to inflate the bid price
Both beliefs are partially true. The problem is what cost-plus does not provide:
No cost ceiling: If subcontractor bids come in higher than expected, the owner pays the difference. If labor takes longer than estimated, the owner pays the difference. If materials are procured inefficiently, the owner pays — plus the GC fee on top.
No incentive to control costs: The GC's fee is typically a percentage of cost. Higher cost means higher fee. There is no mechanism in cost-plus that rewards the GC for saving money.
No predictability for the owner: A business owner who needs to know their total fit-out cost to stay within a TI allowance cannot get that number from a cost-plus GC before the project is complete.
Change order exposure still exists: Cost-plus does not eliminate change orders for work that was not in the original scope. If anything, scope definition is looser in cost-plus contracts — because the GC has no fixed number to protect, they have less incentive to nail down every scope item before starting.
For a 3,000 sqft commercial fit-out with a $180,000 TI allowance, the difference between a project that comes in at $185,000 and one that comes in at $230,000 is the difference between a clean project and an owner funding $50,000 out of operating cash. Cost-plus projects have no mechanism to prevent the second outcome.
Why Fixed-Price Is Safer When Done Correctly
A fixed-price contract specifies a single contract sum for a defined scope of work. If the scope doesn't change, the price doesn't change. The GC bears the risk of estimating and execution errors — not the owner.
The key phrase is "when done correctly." A fixed-price contract is only as reliable as the scope document behind it. A fixed-price number given without a defined scope is just a target that the GC can escape with change orders. A fixed-price number backed by:
- A complete set of permitted drawings
- A written scope document with every finish specified and every trade item listed
- Material and finish selections locked in writing before execution
- Long-lead items identified and procurement timelines confirmed
...is a contract the owner can rely on. Scope is defined. Selections are locked. There is no ambiguity for the GC to exploit with change orders.
The Change-Order Discipline
Change orders on a fixed-price contract are legitimate when the owner changes the scope. They are not legitimate when the GC missed an item that was in the drawings. On a properly scoped fixed-price contract, the GC owns missed items — not the owner.
This is the core financial protection of a fixed-price contract: if the GC misses the hood exhaust penetration through the roof, or fails to include the ADA grab bars in the restroom, or underestimated the tile square footage, those are GC errors — not change orders to the owner.
JK Prestige's fixed-price commercial contracts include a written scope document prepared during the preconstruction phase. Every finish selection, every trade item, and every long-lead procurement item is documented before the contract is executed. Price doesn't change if scope doesn't change — and scope is defined in writing. Learn more about the JK Way.
What a GMP Contract Adds for Larger Projects
A Guaranteed Maximum Price (GMP) contract is appropriate when the scope is still being refined during the design development phase — typically on projects above $500,000 where design complexity warrants a longer preconstruction period.
A GMP contract has three characteristics that distinguish it from both fixed-price and cost-plus:
Open-book costs: The GC provides an actual cost breakdown — subcontractor bids, material pricing, labor rates — not a lump sum. The owner sees what everything costs.
A price ceiling: The GMP is the maximum the owner will pay. Even if costs overrun, the GC is responsible for costs above the GMP. This is the ceiling the GC guarantees.
Savings sharing: If actual costs come in below the GMP, the savings are split between owner and GC per a pre-agreed formula (commonly 50/50 or 75/25 owner-GC). This creates a GC incentive that cost-plus lacks: the GC benefits from controlling costs, because they share in the savings.
For commercial fit-outs in the $500,000–$2M range, a GMP with open-book documentation and a defined savings-sharing formula gives the owner both transparency (cost-plus benefit) and a price ceiling (fixed-price benefit) — the best of both structures.
A Jacksonville Restaurant Owner Who Used Fixed-Price Correctly
A Jacksonville restaurant owner leased a 2,200 sqft vanilla box space in a multi-tenant retail building on the Southside. Her TI allowance was $40/sqft — $88,000 total. Her GC estimated the full restaurant fit-out at $160,000.
The gap was $72,000. She had three options:
- Negotiate a higher TI allowance with the landlord
- Reduce scope to fit within the allowance
- Proceed with a fixed-price contract and fund the gap from reserves
She negotiated the landlord to a $52/sqft allowance ($114,400 total) by providing the GC's itemized fixed-price estimate — not a broker's rule-of-thumb, but a line-item breakdown by trade. The itemized estimate demonstrated that the gap was real, specific, and not padded.
With the adjusted allowance, the gap closed to $45,600 — which she funded from reserves. Construction ran to $163,000 (one owner-directed change: upgraded tile in the dining room added $3,000). The fixed-price contract absorbed the original scope; only the owner's change generated an additional cost. She opened on time and within her cash plan.
The lesson: a fixed-price estimate from a qualified GC is a negotiation tool in the TI allowance discussion, not just a construction number. Landlords respond to specific, documented costs. Vague cost estimates do not move TI allowances.
When Cost-Plus Is Appropriate
Cost-plus is appropriate in limited scenarios:
- Emergency construction: When scope cannot be defined before work must start (hurricane damage, a building fire), cost-plus with a documented fee is the only practical approach
- Renovation of unknown existing conditions: When the scope genuinely cannot be defined until demolition reveals what is behind existing walls — typically in historic or heavily modified buildings where as-built drawings do not exist
- Early-phase preconstruction: Some GCs provide early preconstruction services on a cost-plus or hourly basis before scope is defined
For a standard commercial fit-out of a vanilla box or shell space with known program requirements, cost-plus is not appropriate. The scope can be defined. The selections can be locked. The fixed-price number protects the owner.
How to Evaluate Fixed-Price Bids
When you receive a fixed-price bid, the number alone tells you nothing. Evaluate:
- What is included in the scope: Every fixed-price bid has exclusions. Read them. A bid that excludes "owner-furnished items," "utility connections," and "permits" may be excluding $20,000–40,000 in real costs.
- Is the scope document attached: A fixed-price number without a scope document is just a number. The scope document is the legal definition of what the GC is responsible for.
- Are material selections specified: A fixed-price contract with "allowances" for tile, fixtures, and lighting is not a fixed-price contract — it is a cost-plus contract with a partially defined scope. Allowances must be resolved before contract execution.
- What is the change order process: Understand how changes are priced, who must approve them, and what documentation is required.
JK Prestige delivers a 48-hour written estimate from site walk with a complete scope document, material selections locked, and a fixed price that does not move if the scope does not move.
No call center. No coordinator. A JK principal reviews every inquiry and replies with a real number, not a range, not a follow-up form.
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