Who It’s For
- Anyone who’s heard a budget horror story and wants to avoid repeating it
- Families actively comparing builder bids and trying to read between the lines
- Buyers who don’t fully understand what “allowances” mean in a construction contract
- Anyone mid-research who wants to know what questions to ask before signing
Key Takeaways
- Ask your builder which line items are hard-bid and which are placeholders — before you sign anything.
- Late selections are the biggest cost driver on custom builds. Every change made mid-build costs 2–3x what it would have cost before construction started.
- If your contract is full of allowances, you don’t have a budget. You have a rough sketch. Push for hard bids on anything over $5,000.
- Build a 5–10% contingency and don’t touch it for upgrades, save it for the things nobody can predict.
- Ask any builder you’re considering for a real modifications log from a recent project. If they don’t have one, that’s your answer.
Budget blowouts are the #1 reason custom home projects go sideways. And in almost every case, it’s not the builder’s fault or the client’s fault. It’s actually a systems failure. Here’s what we’ve learned building in Utah and how to protect yourself before you sign anything.
1. Demand a Price Certainty Column in Your Budget
Before you sign anything, ask your builder for a budget that shows not just the line items, but the confidence level behind each one. What’s been bid hard? What’s a placeholder? A good builder can tell you. If they can’t, that’s your answer. At Roots Builders, every line in our budgets carries a certainty marker. It tells you whether a number is based on a hard sub bid, a historical average, or an early estimate that still needs refinement. That transparency is the first layer of protection.
2. Lock Selections Before Breaking Ground
The biggest cost driver on any custom home isn’t materials or labor. It’s changes were made mid-build. Flooring swapped after framing. Countertop upgrades after cabinets are ordered. Electrical changes after the rough-in is done. Every late change costs 2–3x what it would have cost before the shovel went in the ground. We require our clients to have all major selections locked — tile, cabinetry, fixtures, appliances, flooring — before we start. It feels like a lot upfront. It saves tens of thousands on the back end.
3. Understand How ‘Allowances’ Can Lead to Costly Changes for Custom Finishes
A construction allowance is a placeholder. It’s your builder saying ‘we budgeted $8,000 for lighting, but that’s not a real number yet.’ If your contract is full of allowances, your budget is full of guesses. Push for hard bids on anything over $5,000. Allowances aren’t inherently dishonest. For example, sometimes you genuinely haven’t selected a fixture yet, so you don’t know the price. However, they should be the exception, not the rule. If your builder’s budget is 30% allowances, you don’t have a budget. You have a rough sketch.
4. Build a Contingency. Then Don’t Touch It.
Expect 5–10% contingency on any custom build. This isn’t padding for your builder. It’s your buffer against the things no one can predict: a rainy spring that delays your foundation, a material lead time that jumps 6 weeks, a county inspection that requires an extra revision, or a detail in the plans that gets value-engineered in the field. Budget for it upfront and commit to not touching it unless you have to. Clients who blow through their contingency on upgrade decisions mid-build are the ones who end up frustrated at the finish line.
5. Choose a Builder with a Modifications Log
Every change to a custom home, such as client-requested, designer-requested, or field-driven, should be documented in real time with an associated cost. This is called a modifications log, and if your builder doesn’t run one, you’ll be surprised at closeout. Changes accumulate. A door moved here, a window added there, a finish upgraded in the master. Individually, they feel small, but together they can add $60,000–$100,000 to a project if they’re not tracked and approved in real time. Ask to see your builder’s modifications log before you commit. If they don’t have one, that’s a red flag.
Ready to Get Started Building a Custom Home?
Building a custom home in 2026 is still one of the best investments you can make in Utah if you go in with the right systems and the right builder. If you’d like to see what a well-structured budget looks like before you commit to anything, schedule a consultation. We’re happy to walk you through it.
