Over the years, I’ve worked closely with general contractors (GCs) and project managers (PMs), reviewing both initial and final budgets for a range of home projects.

And then, I had a thought:

💡 What if every project followed a similar pattern—not in total cost, but in how the money is allocated?

So, I went back and analyzed six project budgets—renovations and new builds, small homes and large. What I found shocked me.

The dollar figures? Vastly different.
The percentage breakdown? Nearly identical.

Here’s what you need to know about where your money actually goes when building or renovating a home:

Project Percentages

Across all projects, costs consistently followed these five key stages:

1. Documentation (~5-7%)
   Survey, architectural and structural plans, geotechnical reports, permits, and everything needed to begin construction.

2. Construction - To Lock-Up (~35-40%)
   This stage includes foundation, framing, insulation, windows, doors, mechanical, electrical, and drywall—everything to get the home structurally sound and sealed.

3. Construction - Interior Finishing (~35-40%)
   Kitchen cabinets, built-ins, flooring, doors, plumbing fixtures, light fixtures, countertops, railings—this is where your home starts to feel finished.

4. Extras (~3-8%)
   Things like driveway topping, optional retaining walls, and exterior details—often postponed until the end of the project.

5. GC / PM Fees (~10%)
   It’s true what they say. On average, project managers and general contractors take 10%—and for good reason.

Key Differences in Projects

• Smaller projects → A higher percentage went to Documentation (~7%), while the Construction and Interior Finishing stages took a slightly smaller share.

• Renovations → The Extras category was significantly higher (~8%) to account for unexpected issues (hello, hidden water damage and outdated wiring).

• Custom Homes → Homeowners were better at estimating their overall budget than they expected—fewer surprise costs, fewer last-minute upgrades, and better financial control.

The One Thing You Can’t Ignore

Even though the “Extras” stage averaged 8% for renovations and 3% for new homes, I always recommend allowing for a 10-25% contingency.

By the time you reach Interior Finishing, this contingency could be the difference between:

✔️ Upgrading finishes you actually love
✔️ Buying new furniture (a budget item homeowners often forget)
✔️ Taking a much-needed vacation when the dust finally settles

What’s Your Budget Breakdown?

Have you ever broken your home project budget down into percentages instead of numbers? How did it compare?

I’d love to hear from homeowners who’ve done this—drop your numbers in the comments! And if you’re planning a project, take this breakdown as a guide to actually budgeting smart from the start.