Short answer
Remodel budgets drift for three reasons: decisions made after work started, allowances set too low, and what was found behind the walls. The first two are entirely preventable.
Control them by finishing every selection before demolition, insisting on realistic allowances (or better, actual specified products), carrying a 10–20 percent contingency, and requiring that every change order is written and signed before the work happens. A verbal “while you're here, could you…” is the most expensive sentence in remodeling.
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The three reasons budgets drift
1. Decisions made after work started
This is the largest cause and the one entirely within your control. A tile chosen during construction is a tile chosen under pressure, often at a higher price, and frequently requiring rework of something already installed. Every unmade decision at demolition day is a future change order.
2. Allowances that were never realistic
An allowance is a placeholder amount for something not yet selected. When allowances are set low — whether optimistically or to make a bid look competitive — the overage is not a surprise, it is arithmetic that was deferred. See below.
3. What was behind the walls
The legitimate one. Rot, corroded supply lines, an undersized panel, a wall that turns out to be structural. This is what the contingency exists for, and in a pre-1980 house it is close to inevitable — the older-home guide covers what tends to turn up.
Notice the split: two of the three are planning failures, not bad luck. A project where selections were complete and allowances were honest has one source of drift instead of three.
Allowances, and how they hide risk
Allowances make bids comparable and give you flexibility. They also let a bid look cheaper than it will be.
Ask, for every allowance:
- What exactly does it cover? Material only, or material plus labor plus freight? An allowance covering tile but not the setting materials or the labor to install a more complex pattern is not really an allowance.
- What product would this actually buy? Ask for a specific example at that figure. If nobody can name one you would accept, the allowance is fiction.
- What happens if I come in under? You should get the difference back, not have it absorbed.
- Who chooses if I do not decide in time? There must be an answer, and it should not be a surprise.
The better path is fewer allowances. Every item specified with an actual product, model number and price before work starts is an item that cannot drift. This is precisely what a completed design phase produces, and it is the concrete financial argument for doing drawings and selections before construction.
What should a change order contain?
A change order is a written amendment to the contract. It should exist for every deviation, however small, and it must be signed before the work is done.
| Element | Why it matters |
|---|---|
| Description of the change | Specific enough that a stranger could tell whether it was done |
| Reason | Client request, unforeseen condition, or design correction — the pattern is informative |
| Cost, broken into labor and materials | A single lump sum tells you nothing and cannot be checked |
| Schedule impact, in days | The cost of a change is often mostly time, and it is routinely omitted |
| Effect on other work | Whether anything already installed has to be undone |
| Signatures and date, before work begins | The whole point |
Two habits worth adopting. Never approve a change verbally on site — ask for it in writing and be pleasant about it; a professional contractor expects this. And keep a running total of approved changes against the original contract. Individually a change order is small; five of them at two percent each is ten percent, and nobody notices unless someone is counting.
How big should your contingency be?
| Project type | Suggested contingency |
|---|---|
| New construction, fully specified | 5–10% |
| Remodel in a house built after 1990 | 10–15% |
| Remodel in a house built before 1980 | 15–20% |
| Older home with known foundation, electrical or plumbing issues | 20%+ |
| Furnishing-only project, no construction | 5–10% for freight, damage and replacement |
Two rules about the contingency. It is part of the budget, not on top of it — if your ceiling is a fixed number, the scope has to fit inside that number with the contingency reserved. And it is for the unforeseen, not for upgrades. Spending it in week two on a nicer faucet leaves nothing for the rotten subfloor in week six.
Payment schedules that protect you
Payments should follow completed work, not the calendar and not the contractor's cash flow.
- A modest deposit to secure the schedule and order long-lead items. Be cautious about large up-front percentages.
- Progress payments tied to milestones — rough-in complete and inspected, drywall complete, cabinetry installed — not to dates.
- A meaningful final payment held until the punch list is genuinely finished. If the last payment is trivial, the punch list takes months.
- Ask about lien waivers. In Texas, subcontractors and suppliers have lien rights against your property. Conditional and unconditional waivers, collected as you pay, are the mechanism that protects you from paying twice. Ask your contractor how they handle them, and consider your own legal advice on a large project.
- Keep the paper. Contract, change orders, invoices, waivers, permits, warranties, and photos of the open walls. One folder, one place.
Reading and comparing estimates
The lowest number is frequently the most expensive outcome. When comparing estimates, look at what is different rather than what is cheaper:
- Is the scope identical? Bids priced against different assumptions are not comparable.
- How many allowances, and at what levels? A bid with generous allowances may be honestly higher than one with thin ones.
- Is demolition, disposal, protection and clean-up included? Frequently omitted, always necessary.
- Are permits, engineering and inspections in there?
- Is there a project management or supervision line? If not, ask who is running the job and how they are paid for it.
- What is explicitly excluded? The exclusions list tells you more about a bid than the inclusions do.
How this interacts with your delivery model is covered in design-build vs hiring separately — competitive bidding gets you three prices for one scope; design-build gets you cost feedback early enough to change the design for free.
Habits that keep a budget honest
- Finish every selection before demolition. All of them, down to the cabinet knobs.
- Write down the number you will not exceed and tell your designer and contractor what it is. Withholding it guarantees a scheme you cannot afford.
- Separate “must” from “want” at the start, and keep the want list visible. If the contingency survives, you have a ready-made list.
- Approve nothing verbally.
- Track approved changes cumulatively, as a percentage of the original contract.
- Ask for a weekly written update: what happened, what is next, what decisions are needed, what it costs.
- Resist mid-project upgrades. The moment the space is visible is the moment everything looks worth spending more on. Write it on the want list and decide at the end.
Key takeaways
- Two of the three causes of budget drift — late decisions and thin allowances — are planning failures, not bad luck.
- Interrogate every allowance: what it covers, what it would actually buy, and what happens if you come in under.
- Every change order in writing, itemized, with schedule impact, signed before work starts.
- Track approved changes cumulatively — five small ones is not a small number.
- Carry 10–20 percent contingency inside the budget, and reserve it for the unforeseen.
- Tie payments to inspected milestones, and keep a meaningful final payment.
- Compare estimates on scope, allowances and exclusions — never on the bottom line alone.
Frequently asked questions
How much do remodels typically go over budget?
Can I refuse to pay for a change order?
What is a reasonable deposit to pay a contractor?
Should I keep money back at the end?
What is a lien waiver and do I need one?
Jan has practiced interior design in Dallas since 1997 and founded Chateau Concepts in 2001. She holds a BFA in Interior Design from the University of North Texas. She designs and general-contracts residential and commercial projects across the Park Cities, Preston Hollow and North Dallas. Read her full profile →
Written and reviewed by Jan Revels before publicationWork with Chateau Concepts
Jan Revels handles both sides of a project in Dallas and the Park Cities — the design and the build.