How Do Contractors Charge — By the Hour, by Square Foot, or by Project?

Understanding how a contractor's pricing model works helps you compare quotes accurately and avoid surprises. In South Florida, most licensed general contractors use one of a few standard pricing structures. Here's how each one works, the pros and cons, and what's typical for different project types.

Fixed Price (Lump Sum) Contracts

How it works: The contractor reviews the full scope of work and provides a single fixed price for the entire project, based on detailed plans and specifications. This is the most common pricing model for defined-scope projects like kitchen remodels, bathroom renovations, and additions.

Pros for homeowners:

• Budget certainty — you know the total cost upfront

• The contractor bears the risk if their estimate of labor and material costs is off

• Easier to compare apples-to-apples between contractor bids

Cons for homeowners:

• Less flexibility for mid-project changes (change orders typically apply, see below)

• Requires a well-defined scope upfront, which means more design and planning time before signing

• Contractors may build in a buffer for uncertainty, which can mean you're paying a small premium for that price certainty

Best for: Most residential remodeling projects with a clearly defined scope — kitchens, bathrooms, additions, window/door replacement, roofing.

Cost-Plus Contracts

How it works: You pay the actual cost of labor and materials, plus an agreed-upon percentage (typically 10% to 20%) or fixed fee for the contractor's overhead and profit. You see the actual invoices for materials and labor as the project progresses.

Pros for homeowners:

• Full transparency into actual costs

• No padding for "unknown unknowns" — you pay for what's actually used

• Flexible for projects where the scope may evolve as work progresses

Cons for homeowners:

• No budget certainty upfront — the final cost isn't known until the project is complete

• Requires trust in the contractor's reporting and record-keeping

• Can incentivize less efficient work if not structured with a cap or target budget

Best for: Renovation projects in older homes where significant unknowns exist (uncertain structural conditions, potential hidden damage), or custom high-end projects where scope flexibility is valued over price certainty.

Time and Materials (T&M)

How it works: Similar to cost-plus, but typically used for smaller-scale work or repairs rather than full remodels. You pay an hourly labor rate plus the cost of materials used.

Pros for homeowners:

• Appropriate for unpredictable scope — repairs, troubleshooting, smaller jobs

• No need for extensive upfront planning for simple work

Cons for homeowners:

• No cost certainty

• Less common for full remodeling projects since it doesn't incentivize efficiency on larger jobs

Best for: Repairs, small handyman-scale work, or situations where the scope can't be defined in advance (e.g., diagnosing and fixing an unknown plumbing issue).

Per-Square-Foot Pricing

How it works: Some contractors quote certain project types (additions, whole-home renovations, new construction) using a price-per-square-foot framework as a starting point for estimating, which is then refined into a detailed proposal based on actual scope and finish selections.

Important caveat: Per-square-foot pricing is a useful planning tool for ballpark budgeting, but it should never be the final contract mechanism. Two additions of the same square footage can vary enormously in cost based on finish level, structural complexity, and systems requirements. Be wary of any contractor who wants to finalize a contract on a square-footage basis alone without a detailed scope of work.

Best for: Initial budget conversations and ballpark estimating — not final contract pricing.

What's Typical for Different Project Types in South Florida

• Kitchen and bathroom remodels: Fixed price is the norm

• Additions and whole-home renovations: Fixed price based on detailed plans, sometimes with cost-plus provisions for specific high-uncertainty elements (like foundation work in older homes)

• Roofing and window/door replacement: Fixed price, typically based on a detailed measurement and product specification

• Repairs and smaller handyman-scale work: Time and materials or a small fixed price for the specific task

Change Orders: The Important Detail in Any Pricing Model

Regardless of the pricing structure, almost every construction contract includes a process for change orders — formal documented changes to the scope of work that adjust the price (and sometimes the timeline) accordingly. Change orders are normal and expected; they account for homeowner-requested changes (upgrading a finish, adding a feature) and unforeseen conditions discovered during construction (hidden damage, code-required upgrades not anticipated in the original scope).

A well-drafted contract clearly defines how change orders are documented, priced, and approved — protecting both you and the contractor from disputes about scope and cost as the project unfolds.

What to Ask Before Signing

Regardless of pricing model, ask your contractor:

1. What exactly is included in this price, and what isn't?

2. How are change orders handled, priced, and documented?

3. What's the payment/draw schedule tied to project milestones?

4. If cost-plus or T&M, can I see itemized invoices as the project progresses?

A contractor who answers these questions clearly and in writing is one you can trust to manage your project transparently.

Kinetic Construction provides detailed, fixed-price proposals for the vast majority of our residential projects, with full transparency on what's included. Call us at (954) 639-2154 or visit kineticconstructionusa.com.