Owners comparing average change order percentage across data centers, multifamily, and healthcare construction are looking for three clean numbers to stack side by side. What actually exists is closer to three different stories — a set of structural risk factors for data centers, a body of RFI-cost data for multifamily, and a trade-press benchmark target for healthcare — none of which reduces cleanly to one comparable percentage per asset class. Here's what's actually confirmed for each, and what predicts exposure better than the category label does.
Why a clean three-way comparison doesn't exist in the published data
As covered in more detail in average change order percentage by project type: what the data actually shows, the studies and industry surveys that produce change order figures mostly report at the level of "construction projects" broadly — typically an 8-15% range of contract value, with some sources citing figures as high as 25% or more on poorly coordinated work. They don't consistently break that number out by asset class. That gap doesn't close just because the comparison narrows to three specific categories instead of "all project types." Data centers, multifamily, and healthcare each have real, sourced information attached to their change order risk — it's just not the same kind of information in each case, which is exactly why a single comparable percentage per category doesn't hold up to citing.
Data centers: structural risk factors, not a confirmed percentage
No study we could verify publishes a data-center-specific average change order percentage. What is well documented is why the structural risk runs high on this asset class, as covered in why data centers need a constructability review consultant more than any other asset class: MEP systems typically run 60-75% of a data center's construction budget, roughly double the 30-40% share on standard commercial work, and a meaningful share of those systems are built twice under 2N or N+1 redundancy requirements. Add hyperscaler-driven fast-track schedules that compress the gap between a finished set and procurement, and every factor that drives change order exposure elsewhere — MEP density, duplicated scope, compressed review time — is elevated at once on this asset class.
That combination predicts higher exposure without needing a specific percentage to make the case. A missed coordination conflict on a system that's 60-75% of the budget, built in duplicate, reviewed on a shortened schedule, carries more weight than the same missed conflict on a project where MEP is a third of the scope.
Multifamily: RFI cost data stands in for a missing change order figure
Multifamily construction has a different gap: the change order percentage figure specifically isn't published in a form we could confirm, but a related, well-documented dataset exists on RFIs — the requests for information that frequently precede a change order when a drawing set doesn't answer a field question cleanly. A Navigant Construction Forum study sampling 1,362 projects worldwide found an average of 9.9 RFIs per $1 million of construction value, with each RFI costing a construction firm roughly $1,080 to review and respond to, and the collective cost across an average project running around $859,680. That study wasn't multifamily-specific — it covered projects of all types — but it's been cited repeatedly in multifamily development coverage as the closest available proxy for how much unresolved documentation ambiguity actually costs a project before it ever becomes a formal change order.
RFIs and change orders aren't the same event, but a set that generates a high volume of RFIs is a set with unresolved coordination questions — and a meaningful share of those questions get resolved as a change order once the answer requires more than a written clarification. On multifamily work specifically, where unit-type repetition and tight floor-to-floor MEP routing create a lot of chances for one discipline's sheet to disagree with another's, RFI volume is a reasonable leading indicator even without a confirmed change order percentage to match it.
Healthcare: a trade-press benchmark, not a peer-reviewed figure
Healthcare construction has the opposite issue from data centers and multifamily: there's a specific number circulating, but it's industry commentary and benchmarking language rather than a disclosed, peer-reviewed study. Trade coverage of hospital construction repeatedly frames a "Project Change Order Percentage" under roughly 5% as the mark of disciplined pre-construction planning, against a general commercial benchmark closer to 10-15%. Some of that same coverage describes disciplined hospital programs limiting cost growth to 3-5% of contract value, versus 15-20% or more on poorly managed projects.
Academic research on hospital construction change dynamics has found that changes on hospital projects tend to arrive later in the project lifecycle than on other building types — driven by categories like evolving equipment and systems requirements and shifting regulatory conditions — which disrupts execution differently than a change identified earlier in design. That's a documented pattern in the research, even where the specific percentage benchmarks circulating in trade press aren't independently verified studies.
Healthcare's change drivers also skew toward categories that are harder to catch in a pre-bid document review alone — medical equipment specifications and regulatory requirements can shift after the drawings are already coordinated, in a way a change to a standard commercial finish package doesn't. That's a real difference in when and why healthcare projects change, even without a hard percentage to benchmark it against.
Putting the three side by side
None of these three data points are directly comparable to each other, and presenting them as one table with three percentages would overstate what's actually known. What they do share is a common underlying driver, which is the more useful thing to benchmark against than the category label.
What actually predicts change order risk across all three
The pattern that holds across data centers, multifamily, and healthcare — and across every other asset class, as covered in where coordination-error costs actually come from — is trade density and interface count, not the building type. A data center's exposure comes from MEP being nearly the whole building, built twice. A multifamily project's exposure comes from repeated unit types multiplying the number of places a routing conflict can recur. A hospital's exposure comes from equipment and systems requirements that keep moving after the drawings are locked. Three different mechanisms, same underlying question: how many disciplines have to agree with each other, and how late in the process is that agreement still changing.
That's why a category-wide average, even a confirmed one, would still be the wrong number to plan against. A specific project's exposure is a function of its own trade density and interface count — not the average across every project that happens to share its building-type label.
Key takeaways
- No verified study publishes a clean, comparable change order percentage across data centers, multifamily, and healthcare — each asset class has a different kind of evidence attached to its risk instead.
- Data centers carry elevated structural risk from MEP budget share (60-75% vs. 30-40% typical), 2N/N+1 redundancy, and fast-track schedules — without a confirmed change-order percentage to cite.
- Multifamily's closest available proxy is RFI cost data: roughly 9.9 RFIs per $1M of construction value and ~$859,680 in collective RFI cost per average project, per a Navigant Construction Forum study of 1,362 projects.
- Healthcare's circulating ~5% target benchmark is trade-press commentary, not a disclosed peer-reviewed figure — though research does document that hospital changes trend later in the project lifecycle than on other building types.
- Trade density and interface count — not the category label — predict change order exposure across all three asset classes.
What this means for owners comparing across asset classes
An owner weighing a data center against a multifamily project against a hospital shouldn't expect a fair three-way percentage comparison to exist, because the underlying data doesn't support one. What's available instead is asset-class-specific context about why each type carries the risk it does, paired with the same benchmark that applies regardless of category: a documented, sheet-located review of the specific set in front of you, priced out discipline by discipline, before bid. That number is about the project, not a category average standing in for it.
Frequently Asked Questions
Is there a single reliable average change order percentage for data centers, multifamily, and healthcare?
No. No verified study publishes a clean, comparable change order percentage across those three asset classes. Data centers have documented structural risk factors (MEP budget share, redundancy, fast-track schedules) without a confirmed percentage; multifamily has RFI cost data as a proxy; healthcare has a trade-press benchmark target rather than a peer-reviewed figure.
Why do data centers have higher change order risk if there's no confirmed percentage?
Because the structural drivers are well documented even without a single number attached to them. MEP systems run 60-75% of a data center's construction budget versus 30-40% on typical commercial work, a meaningful share of those systems are built twice for redundancy, and fast-track hyperscaler schedules compress the review window before procurement — all factors that raise exposure independent of any specific percentage.
What does RFI data tell owners about multifamily change order risk?
A Navigant Construction Forum study of 1,362 projects found an average of 9.9 RFIs per $1 million of construction value, costing roughly $1,080 each to review and respond to, for a collective cost of about $859,680 per average project. That study wasn't multifamily-specific, but high RFI volume signals unresolved documentation questions — a meaningful share of which convert into change orders — making it a useful leading indicator where a direct change order percentage isn't available.
Is the "5% change order target" for hospital construction a real, verified figure?
It's a benchmark that shows up repeatedly in healthcare construction trade coverage, generally contrasted against a 10-15% general commercial range, but it isn't a disclosed, peer-reviewed study. Separate academic research does document that hospital construction changes tend to arrive later in the project lifecycle than on other building types, driven by evolving equipment and regulatory requirements.
If there's no reliable per-type percentage, how should an owner benchmark change order risk on their own project?
Benchmark against the project's own trade density and interface count rather than its category label. A documented, sheet-located review that prices out where the specific drawings and specs disagree, discipline by discipline, before bid gives a number that reflects the actual project — not an industry or category average standing in for it.