What’s the Difference Between Fixed Price, Cost Plus, and Time & Materials?
Updated: Sep 1
What’s the Difference Between Fixed Price, Cost Plus, and Time & Materials?
The biggest difference between these construction pricing methods is how the contractor calculates what you ultimately pay and who takes on the risk when actual project costs differ from what was expected.
Fixed Price: The contractor agrees to complete a defined scope of work for an agreed price. The price generally stays the same unless the scope changes, unforeseen conditions are addressed under the contract, or another contract provision allows an adjustment. Changes should be documented through the project's change-order process.
Cost Plus: The homeowner pays the actual agreed project costs plus a contractor fee or markup. Depending on the contract, that fee might be a percentage, a fixed fee, or structured another way. Because actual costs can change, the final project price may change as well.
Time and Materials: The homeowner pays for the actual labor time and materials used on the project, typically according to rates and markups established in the contract. This can be useful when the amount of work is difficult to determine in advance.
None of these pricing methods is automatically better than the others. The right choice depends on the project, how clearly the scope can be defined, how much uncertainty exists, and how the homeowner and contractor want to allocate financial risk.
Before signing a construction contract, it's important to understand which pricing method you're agreeing to, what is included in the price, what can cause that price to change, and what documentation you'll receive along the way.
Fixed-Price Contract
With a fixed-price contract, the contractor agrees to complete a defined scope of work for an agreed price. The contractor estimates the labor, materials, subcontractors, equipment, overhead, profit, and other anticipated costs before establishing that price.
The contractor generally assumes more of the financial risk if those costs are higher than expected. At the same time, if the contractor manages the project efficiently or obtains materials for less than anticipated, the homeowner doesn't automatically receive a reduction in the contract price.
The important word here is scope. A fixed price only covers the work defined by the contract. Changes requested by the homeowner, unforeseen conditions, allowances, or other circumstances addressed by the contract can still affect the final price.
Pros
Budget predictability: You have a much clearer idea of what the defined scope of work will cost before construction begins.
Less cost tracking for the homeowner: You're paying for the agreed scope rather than reimbursing the contractor for every individual project expense.
Contractor assumes more pricing risk: If the contractor underestimated certain costs, those increases aren't automatically passed along to you unless the contract provides for them.
Cons
Less flexibility: Changes after the contract is signed can affect both the price and schedule and should be handled through the project's change-order process.
Less visibility into actual contractor costs: Because you're purchasing an agreed scope for an agreed price, you generally won't have the same access to individual project expenses that you would under a cost-based contract.
Cost-Plus Contract
With a cost-plus contract, the homeowner pays the project's actual agreed costs plus the contractor's fee or markup.
Exactly which costs are reimbursable and how the contractor is compensated should be clearly defined in the contract. Some cost-plus agreements use a percentage fee, while others may use a fixed contractor fee or another agreed structure.
Because your final price is based on actual project costs, documentation becomes especially important.
If you’re unsure what financial records a contractor should provide, read Can You Ask a Contractor for Material Receipts?
Pros
Flexibility: Cost-plus can work well when the exact scope is difficult to determine before construction begins, such as some remodeling, repair, or restoration projects.
Greater cost visibility: Because you're paying actual project costs, the contract can require documentation such as invoices, receipts, subcontractor charges, or other records supporting those costs.
Useful for uncertain projects: When hidden conditions make accurate pricing difficult, cost-plus can allow work to proceed without requiring the contractor to build a large amount of contingency into a fixed price.
Cons
Less budget certainty: The final cost isn't necessarily known when construction begins.
More homeowner oversight: You'll need to understand what costs are reimbursable, how the contractor's fee is calculated, and what documentation you're supposed to receive.
Costs can grow: Without good budgeting, communication, and documentation, the final project cost can become significantly higher than the initial estimate.
Time-and-Materials Contract
A time-and-materials contract charges the homeowner based on the actual labor time and materials used, according to rates and markups established in the agreement.
For example, the contract might establish an hourly labor rate, how materials are charged or marked up, equipment rates, and how subcontracted work is handled.
This type of pricing can be particularly useful for smaller projects, repairs, troubleshooting, or work where the contractor can't reasonably know how long the job will take until work begins.
Pros
Works well with unknown conditions: The contractor doesn't have to guess how much labor will be required and add that risk to a fixed price.
Easy to adjust the amount of work: If conditions change or additional work is needed, the pricing mechanism is already established.
Actual usage determines much of the cost: You're paying according to the labor and materials actually used under the terms of the agreement.
Cons
Final price is uncertain: You won't necessarily know exactly what the project will cost before work begins.
Documentation matters: Labor hours, material charges, rates, and markups should be clearly documented.
Efficiency matters: Because labor time affects what you pay, homeowners need a clear understanding of rates, recordkeeping, supervision, and billing practices.
What About Turnkey Construction?
You'll often hear turnkey used alongside fixed-price construction, but they don't technically describe the same thing.
Fixed price describes how the project is priced. Turnkey describes what the contractor is expected to deliver.
A turnkey contractor typically takes responsibility for delivering a completed project that's ready for the owner to use. Depending on the agreement, that could include coordinating design, permits, subcontractors, construction, finishes, and other parts of the project.
A turnkey project can be priced using a fixed-price arrangement, which is why the terms are often used together, but the contract should tell you exactly what is included rather than relying on the word “turnkey” alone.
Which Construction Contract Is Better?
There isn't one pricing method that's best for every construction project.
A fixed-price contract can be a good fit when the scope is clearly defined and budget predictability is a priority.
A cost-plus contract can make sense when actual project costs are difficult to predict but the homeowner wants visibility into those costs.
A time-and-materials contract can work well for repairs, smaller projects, or work where the amount of labor and materials can't reasonably be determined beforehand.
The most important thing is that you understand how you'll be charged, what's included, what can change the price, what documentation you'll receive, and how changes will be handled before you sign the contract.
Before you sign: Understanding the pricing method is only part of reviewing a construction contract. My Home Construction Contracts gui explains other terms homeowners should look for before signing.
The Texas Bricklady Home Building Package includes practical tools for reviewing bids, tracking payments, managing change orders, organizing project documents, and understanding the decisions that can affect your final cost.
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