Before breaking ground, most custom home buyers make a quiet decision. They've reviewed the plans carefully. They've made their selections. They've had the conversations. Change orders, they tell themselves, are for people who didn't plan well. That won't be them.
It's a reasonable assumption. It's also almost always wrong and not because of anything the buyer did or didn't do.
Change orders don't happen because buyers are indecisive. They happen because building a custom home is a 12-18 month process with hundreds of variables, and reality rarely matches a set of plans exactly. Understanding what triggers them and what the markup on each one means for your final number is one of the most important things a buyer can know before signing.
What is a change order markup, and why does it apply to every build?
A change order is any modification to the original contract scope, adding work, removing work, substituting a material, or responding to a site condition that wasn't anticipated. When a change order is issued, your builder doesn't charge you the raw cost of the change. They charge you the cost plus a markup percentage.
That markup percentage is set in your contract at signing. It covers the builder's overhead, coordination time, and profit on the change. The industry range for custom builders runs from 15-35%, and it applies uniformly to every change order for the life of the build, regardless of whether you initiated the change or the builder did.
Most buyers see this clause, note it, and move on. They're not planning to make changes. What they don't account for is everything that triggers a change order that has nothing to do with changing their mind.
What actually triggers change orders in a custom home build?
Site conditions-The lot looked straightforward. Then excavation revealed rock, poor drainage, or soil that required additional preparation. None of that was in the original contract. All of it becomes a change order.
Material substitutions- A specified product gets discontinued mid-build. The manufacturer changes lead times. Your builder substitutes something comparable and the price difference, plus markup, appears on your next invoice.
Allowance overages- When you go over an allowance on flooring, fixtures, cabinetry, or tile, the overage doesn't just get added to your bill at cost. It becomes a change order, which means it carries the markup percentage on top.
Builder-initiated adjustments-Field conditions sometimes require changes to what was drawn on paper. A structural element needs to move. A mechanical system requires a different routing. These changes happen at the builder's discretion and they still carry your contract's markup rate.
The buyer who planned zero change orders often ends up with fifteen by the time the build is complete, not because they changed their mind, but because that's how construction works.
How does the markup compound across a build?
Individually, change orders feel manageable. A $3,000 site condition with 25% markup is $3,750. A $5,000 allowance overage with 25% markup is $6,250. A $2,500 material substitution with 25% markup is $3,125.
Together, across a 12-18 month build, they compound. Buyers who tracked every change order from day one consistently report that the cumulative markup added $15,000-$40,000 to their final number, on top of the original overages themselves.
The markup isn't the problem. Not knowing the markup percentage before signing and not tracking the cumulative total against your contingency is where budgets quietly disappear.
What is a realistic contingency for change orders?
The industry standard recommendation is 10-15% of total construction cost as a contingency budget. On a $900,000 build that's $90,000-$135,000. Most buyers either don't know this or don't budget for it, assuming their careful planning makes a large contingency unnecessary.
A contingency isn't an admission that your plans are incomplete. It's an acknowledgment that construction involves variables no contract can fully anticipate. The buyers who finish on budget are almost always the ones who budgeted for the unexpected from the start.
What to ask about change orders before you sign
The change order markup percentage is a contract term which is negotiable before signing, fixed after. Here is what to confirm before you commit.
What is the change order markup percentage, and does it apply to materials only or to the full change order value including labor? Some contracts apply markup to materials only. Others apply it to the full scope. The difference matters significantly on labor-intensive changes.
Is there a different markup structure for owner-initiated changes versus builder-required changes? A change you request and a change the builder makes in response to a site condition are different situations. Some contracts treat them identically. Some don't.
What is the process for approving change orders before work begins? A signed change order with your approval in advance is the standard you're entitled to ask for, and it should be stated explicitly in your contract.
What contingency does the builder recommend for this specific build and lot? A builder who has evaluated your site and plans should be able to give you a realistic number, not a generic percentage.
How do you track change orders during a build?The number that matters isn't the size of any individual change order. It's the cumulative total against your contingency budget. Most buyers track this informally, a rough mental tally, an email folder, a spreadsheet started three months in. By the time the total is alarming, the leverage to slow it down is gone.
The Change Order Tracker inside Foundation First tracks every change order in real time, calculates your cumulative total including markup, and shows your remaining contingency against your original budget. The buyer who sees they've consumed 60% of their contingency in month four makes different decisions than the buyer who finds out the total at the final walkthrough.
FAQ: Change orders in custom home builds
Why do change orders happen even when you plan carefully?
Site conditions, material substitutions, allowance overages, and builder-initiated field adjustments all trigger change orders regardless of how thoroughly a buyer planned. Most buyers experience 10-20 change orders over the course of a build, the majority of which they didn't anticipate at signing.
What is a typical change order markup on a custom home build?
Industry range is 15-35% for most custom builders, applied to every change order for the life of the build. The percentage is set in the contract at signing and applies whether the change was buyer-initiated or builder-required.
Can you negotiate the change order markup before signing?
Yes, but only before signing. The markup percentage is a contract term. After the contract is signed it is fixed. This is one of the specific terms to address during builder selection and contract review, before you have committed to a builder.
How much contingency should you budget for change orders?
Industry standard is 10-15% of total construction cost. On a $900,000 build that's $90,000-$135,000. Buyers who budget a realistic contingency from the start consistently report less financial stress mid-build than buyers who planned for zero change orders.
Start with the free guide: 7 Costly Mistakes Custom Home Buyers Make Before They Even Sign. thebuildingedit.com
Plan Smart. Build Strong.
Gael
The Building Edit