TLDR
Adjusters use component-based estimating software built for all types of restoration work. The number it produces is a theoretical average, not a real contractor's price. The gap is usually a scope issue, a unit price issue, or both, and an experienced contractor can show you exactly where it is.
If your adjuster's number came in lower than your contractor's quote, you're not alone and it doesn't automatically mean someone is wrong. It usually means two people arrived at a price using completely different methods, and understanding why that gap exists is the first step to knowing what to do about it.
How Do Insurance Adjusters Estimate a Roof?
Adjusters use estimating software to price restoration work. The two most common are Xactimate and Symbility. Both were built to estimate restoration work across every category of property damage: fires, floods, structural repairs, roofing. You could theoretically use either one to estimate a skyscraper. They're powerful tools for large-scale restoration work. For pricing a roof replacement, they're a lot more complicated than they need to be.
The software is component-based. That means every single action involved in a roof replacement is its own separate line item. Tear-off is one line item. Replacement is another. Step flashing, drip edge, pipe jacks, vents, decking, underlayment, ice and water shield, each one is its own entry. On a standard single-family home, there can be 40 or more line items that could potentially apply to a roof estimate.
The price assigned to each line item is based on market surveys of what contractors in a given area are charging. The software averages those numbers. That's important: average means some contractors in the market are lower, and some are higher. Even when the scope is perfect and every line item is accounted for, the software's output is a theoretical number based on market averages. It is not a real contractor's real price.
Worth knowing: we hold Xactimate Level 1 and Level 2 certification. That means when we review an adjuster's scope, we're reading it the way it was written, and we can tell the difference between a line item that was genuinely missed and one that simply wasn't asked for.
Why Has the Line Item Estimating System Become a Problem?
Each insurance carrier, and sometimes each individual adjusting team within the same carrier, has internal policies about which line items they will and won't pay for. One team might pay 18 of the 40 possible line items. A different team at the same company might pay a different 12. These policies change. They vary adjuster to adjuster. They aren't published anywhere.
The practical result is that contractors who use these tools often submit all 40 potential line items just to make sure the 18 or 21 the carrier will approve are in there. If you don't ask for it, the carrier won't pay for it. So the process becomes: submit everything, fight over what gets approved, negotiate down to something workable. The gap between what contractors submit and what carriers pay has widened to the point where it's no longer a productive conversation. It's line item combat.
A contractor who knows their real numbers doesn't need to play that game. A legitimate roofing contractor can stand on the front lawn of a house and get a reasonably accurate price based on the variables that actually drive roofing costs: pitch, stories, access, number of layers, waste factor for material, and complexity from skylights, chimneys, or irregular geometry. That's the list. The number of squares times the price per square, or the square footage times the price per square foot, adjusted for those variables, is a real number that reflects what the job actually costs.
If you want to get more granular, you do what's called a take-off: a list of every material the job requires, the labor cost per square, an estimate for permit costs, and a handful of general condition items like safety equipment. Add the margin the contractor needs to be stable and profitable, and that's the estimate. If you know your numbers as a contractor, that process is straightforward. It doesn't require software built to estimate flood restoration.
Why Do Some Contractors Use This Software If It Doesn't Reflect Real Pricing?
The argument for using the same software as the carrier is that you're speaking the same language. There's some truth to that. But what happens more often is that the software becomes a tool for inflating a claim rather than pricing a roof. The software produces a different price per square on every house, which doesn't reflect how roofing costs actually work. A contractor who relies on that output instead of knowing their own numbers is either not confident in their pricing or using the software's complexity as cover to run the number up.
Contractors who build their business on beating the carrier's number on the back end don't need to know their real costs. The margins are wide enough that it doesn't matter. That works until it doesn't, and it doesn't produce better roofs.
What Does This Mean for Me as a Homeowner?
When your carrier approves a full replacement but the number feels low, the question isn't whether someone made a mistake. The question is whether your contractor can show you a real scope of work with a real price and explain specifically where the gap is. That's a concrete conversation. A contractor with actual numbers can tell you: here's what the carrier approved, here's what the job costs, here's where the difference is and why.
That documented scope is also what goes back to your carrier if additional items need to be addressed. Not a stack of line items, but a clear, specific explanation of what's required and why.
For a deeper look at how the claims process works from the beginning: Hail and Wind Insurance Claims: A Homeowner's Guide to Doing It Right. If you've already received an adjuster estimate and want to understand what to do next: What to Do When the Adjuster's Number Feels Low or Your Claim Was Denied.
Frequently Asked Questions
What is Xactimate or Symbility?
Xactimate and Symbility are estimating software platforms used by insurance adjusters to price restoration work. Both are component-based, meaning every action in a repair or replacement is a separate line item, and prices are based on market surveys of what contractors in a given area are charging. They're widely used in the insurance industry but produce theoretical pricing based on averages rather than a specific contractor's actual costs.
Why do insurance estimates come in lower than contractor quotes?
Usually a combination of two things: the software uses market averages, so any contractor priced above average will see a gap, and carrier-specific line item policies mean some items a contractor includes may not be approved by that particular carrier or adjusting team. Neither of these is automatically bad faith. It's a structural gap between how adjusters estimate and how contractors price.
Should my contractor use Xactimate or Symbility?
A legitimate roofing contractor should know their own numbers well enough that they don't need restoration estimating software to figure out what a roof costs. Some contractors use it because it speaks the same language as the carrier. Others use it as a tool to inflate submissions and negotiate down. If your contractor can't explain their price without the software, that's worth asking about.
What is a supplement and when is it legitimate?
A supplement is a formal request to add to an approved insurance claim. The legitimate version covers something genuinely unforeseen discovered once the roof is open: decking that looked solid from outside but showed rot once old materials were removed, for example. Physical conditions that weren't visible during the initial inspection. That's a real reason for a scope and price to change mid-project.
The term gets used loosely in storm restoration to describe billing for items on the back end that were simply missed or omitted up front. When a contractor has a transparent scope of work and a transparent price agreed to before the job starts, most of what gets called a "supplement" shouldn't exist. Items that were part of the roof from the beginning should have been in the original scope. A supplement should mean something unexpected, with a specific explanation of what it is and why it wasn't foreseeable.
Is the gap between insurance estimates and contractor quotes always fixable?
Not always. Sometimes the carrier's approved amount is close enough to a contractor's real price that the difference is manageable. Sometimes there's a policy limitation that caps coverage regardless of what the job costs. And sometimes the gap reflects a contractor who's priced higher than the market warrants. Understanding which situation you're in is the starting point.
Disclosure: The information in this article is for general educational purposes only and is not intended as legal advice, insurance advice, or public adjusting services. Insurance policies are contracts between the homeowner and the insurance carrier, and coverage determinations are made solely by the carrier based on the terms of the policy. Homeowners should consult their insurance agent, insurance carrier, or legal counsel with specific questions regarding coverage or claims. Contractors do not interpret policy language or determine coverage.
