Most installed prices for home repairs have no official source. No government agency publishes what a new roof or a water heater swap costs. So every CostPlain cost page shows its work in three layers: the published estimates side by side, a build-up from parts you can check, and an explanation of why the numbers differ. This page sets out how each layer works and where its limits are.
The three layers
1. Published estimates, side by side
Each cost page opens with a small table of named published figures. For each one we give the figure, the date it was published or read, and what it measures: insurance claims, a defined job in an industry report, a survey run by a site that sells leads, or a federal database. We label these “published estimates”.
We never average them into one number. Two figures that measure different things don’t make a truer third figure when you blend them; they just hide what each one means. And we never present a published range from a secondary source as fact.
2. A worked build-up
Next, we build the cost from its parts:
- Materials: quantity times a dated price from a named retailer or maker, with the date we saw it.
- Labor: hours times the BLS median hourly wage for the trade, times an employer-cost uplift for benefits and payroll taxes.
- Overhead and profit: a percentage on top, shown as its own line.
The arithmetic is on the page, and the calculators let you change the inputs. A quote from a contractor near you is a better number than ours; the build-up helps you see what that quote should cover.
3. Why the numbers differ
Finally, we explain what each source includes or leaves out: tear-off and disposal, permits, markup, region, job size, and whether the figure is an average of real jobs or a model of one defined job. That is usually where a large gap comes from.
Roofs are a good example. Verisk, which analyzes insurance claims, puts the average insured roof replacement in 2025 at $17,631. That is an average cost per insurance claim, mostly after wind and hail. The Remodeling 2025 Cost vs. Value Report (www.costvsvalue.com) puts an asphalt shingle roof replacement at $31,871 nationally. That figure models one defined job: a full tear-off and 30 squares (3,000 square feet) of shingles on a hip roof with two skylights. Its methodology says its building cost data also come from Verisk, so the gap is mostly scope, not a disagreement about prices. Neither figure is wrong. They answer different questions.
© 2025 Zonda Media, a Delaware Corporation. Complete data from the Remodeling 2025 Cost vs. Value Report can be downloaded free at www.costvsvalue.com.
How we price labor
The wage. We use the national median hourly wage for the trade from the Bureau of Labor Statistics, May 2025 data, released in May 2026. For roofers that is $26.65 an hour; for plumbers, $30.67. A median is the wage half of workers earn more than and half less than. It covers employees only, not the self-employed, and it is a wage, not what a contractor charges you.
The employer-cost uplift. An employer pays more than the wage. In June 2026, construction employers paid on average $51.96 an hour in total compensation for every $36.13 in wages (BLS Employer Costs for Employee Compensation). So we multiply the wage by 1.44 to cover benefits and payroll taxes. This is an average across the construction industry, not the cost for any one trade or company.
BLS has said that, starting with December 2026 data published in March 2027, it will remove workers’ compensation costs from these figures. When we move to that data, we will say that the uplift no longer includes workers’ compensation, which is a large cost in trades such as roofing.
The hours. We found no free public source that says how long a home repair job takes. So labor hours on every page are marked “our assumption”, with a sentence on how we got there, and the calculator lets you change them. Where we can, we back-check an hours figure against a published dollar figure and say so.
Overhead and profit
A contractor’s price also covers the office, insurance, vehicles, time spent on permits, and a margin. Our default is 20% on top of labor and materials, marked “our assumption”. Insurance estimates often use 10% overhead plus 10% profit, which FEMA’s flood insurance program has called the typical charge where a general contractor coordinates several trades. That is a claims convention, not a measured market margin, and real quotes vary, so you can set your own figure.
A worked example
Here is the arithmetic with round, made-up inputs, so you can follow it. Say a small roofing job needs $1,000 of materials and 10 hours of labor.
| Line | Working | Amount |
|---|---|---|
| Materials | Example figure | $1,000.00 |
| Labor rate | $26.65 BLS median × 1.44 uplift | $38.38 an hour |
| Labor | 10 hours (example) × $38.38 | $383.80 |
| Subtotal | $1,000.00 + $383.80 | $1,383.80 |
| Overhead and profit | 20% (our assumption) × $1,383.80 | $276.76 |
| Estimate | $1,660.56 |
On a real page, the materials line lists each item with its quantity, price, seller and date, and the hours line explains the assumption. Try it with your own figures in the roof replacement cost calculator.
The cost register
Every shared figure, such as a wage, the uplift, a published estimate or a material price, goes into one register before a page uses it. For each figure the register records the value, the source and its link, the date we read it, and what it measures. Pages draw from the register, so the same wage shows the same way everywhere, and a change is made in one place.
We recheck any figure older than 12 months. BLS wages are rechecked when the next annual wage data come out, and the uplift when BLS publishes a new release. A page shows an updated date only when its content really changed.
What we don’t use, and why
- RSMeans. This is a widely used commercial database of contractor unit costs. It is licensed data, and we do not use it.
- Remodeling’s Cost vs. Value Report. Its reuse guidelines allow short quotes in text, but not copied tables, and not use inside a calculator or tool without a license. So we quote at most a figure or two in a sentence, with its credit, and none of our calculators use it.
- Figures we can’t trace. If we can’t find where a number came from or what it measures, we leave it out or say plainly that it is unconfirmed.
We sometimes use federal compilations, such as the National Renewable Energy Laboratory’s residential efficiency measures database, as a labelled cross-check. We say what year’s dollars they are in, and we never use one as a page’s only price.
What an estimate can’t know
- Your region. We use national figures. Wages, material prices and demand vary by state and city.
- Your house. Size, age, layout and condition matter, and so does what is hidden: rotten decking, a cracked sewer line, old wiring. A contractor may find it only once work starts.
- Access. A steep roof, a tight crawl space, a long trench or a basement with no outside door all take more time and equipment.
- Code and permits. Building codes are adopted locally, and permit fees and inspections vary by city and county. Older homes may also need lead-safe or asbestos work. Your local building department decides what the job needs.
So our numbers are estimates, not quotes, and never a verdict on whether a price is right. Use them to ask better questions. A licensed local contractor prices the real job, and the permit office decides what it requires. Our editorial policy covers how pages are checked, and our disclaimer sets out the limits. If a figure looks wrong, please tell us.