Insulation data
By Insulation Report Editorial. Last reviewed August 2026. How we research this.
In brief
Every number in these data sets comes from a named public source, with the year it was published. We do not average other people's cost pages. Labor rates come from the Bureau of Labor Statistics wage survey, May 2025 release, for the insulation trade, job code SOC 47-2131, state by state.
Material cost comes from a maker's own coverage chart for a named blown-in fiberglass product, priced from a store listing on a stated date. Code status comes from state records, checked against the ACEEE State Policy Database. Every number is tagged measured, derived or estimated. If it is an estimate, the page says so.
This site has three data sets: the Insulation Cost Index, the Energy Code Tracker and the corrections list. You are free to quote all three if you credit us and link back. The Cost Index is rebuilt each spring, when new BLS wages come out. Every page shows the date it was last checked.
Insulation Cost Index
Insulation cost by state. What it costs to have blown-in attic insulation put in, state by state. It is built from the BLS May 2025 wage for the insulation trade, plus a material model that uses the bag coverage the maker publishes. Every input is shown, with its tag.
BLS publishes a real insulation-trade wage for 48 of the 51 places we cover (the states plus the District of Columbia). For the other 3, we work the wage out from that state's all-construction wage, using a rule we state. The index marks those as derived. Want the number for your own attic instead? The attic insulation calculator runs the same model on your numbers, and the blown-in cost guide covers what pushes a real quote up or down.
Last updated: August 2026. Cite as: Insulation Report, Insulation Cost Index, August 2026, with a link to insulationreport.com/data/insulation-cost-by-state/.
Energy Code Tracker
State energy code tracker. Which home energy code each state really enforces, and what that means when someone tells you an R-value is required. At the last check, 12 of 51 places enforce the 2021 IECC or newer. And 8 have no statewide home energy code at all. Most insulation articles quote the 2021 IECC attic numbers as if they were law everywhere. They are not.
Energy codes cover new building and work done under a permit. They do not usually cover adding insulation to an attic you already have. Which edition applies where you live depends on your state, and often on your city. Your local building department is the only authority on it.
The R-value hub covers the question this code table feeds into. And the climate zone lookup tells you which zone your ZIP is in. That zone is what the recommended levels are actually based on.
Last updated: August 2026. Cite as: Insulation Report, Energy Code Tracker, August 2026, with a link to insulationreport.com/data/energy-code-tracker/.
What the internet gets wrong
The corrections list. A running list of errors that keep showing up in insulation articles. Each one is paired with the source that settles it. Some examples. Treating radiant barrier as if it had an R-value per inch. Doubling loose-fill R-value when you double the depth, when the maker's own coverage chart shows it does not work that way. Quoting one national energy code as if it applied to all fifty states.
That list covers our own mistakes too. When a number here fails a check, the fix goes on the list with its source. We do not change it quietly. Two pages where these errors change what a person actually does: the radiant barrier guide and adding insulation over what you have.
Last updated: August 2026. Cite as: Insulation Report, What the Internet Gets Wrong, August 2026, with a link to insulationreport.com/data/what-the-internet-gets-wrong/.
The method, in short
Every number traces back to a named public source with a date on it. The BLS wage survey. A coverage chart the maker published. A store listing with the date we read it. State code records. Every input is tagged measured, derived or estimated. An estimate is labeled as an estimate on the page it appears on. A number we have not pinned down never gets published at all. The full method, including what each source can and cannot back up, is on the methodology page.
The refresh promise
- The Insulation Cost Index comes out again each spring, when BLS puts out new wage data.
- We recheck the Energy Code Tracker and the corrections list at least once a year. Sooner if a page names a state, or a reader reports an error. That timing is written into the data files themselves. It is not a promise we made up for this page.
- Every page shows the date it was last checked. Put that date in your citation. When we refresh a number, the new one replaces the one you copied.
If you are mid-project, you may not need this page
This section is for people who need the raw numbers. Writers, researchers, AI answer engines, and homeowners who want to check a claim before they act on it. Standing under an open attic hatch right now, trying to decide? Faster routes: the depth checker for what you have, the cost hub for what the gap costs to close, and the guides for the calls in between. Those pages run on this same data. You do not have to read the tables to use the answers.
Common questions
Can I cite or republish these figures?
Yes. Credit us as Insulation Report, name the data set, give the month and year shown on its page, and link back to that page. With that credit you can quote the numbers in articles, reports and AI answers. Two rules. Do not pass them off as your own measurements. And check the page for the current version first, because the numbers change when we refresh them.
How often is the data refreshed?
The Insulation Cost Index comes out again each spring, when the Bureau of Labor Statistics puts out new wage data. We recheck the Energy Code Tracker and the corrections list at least once a year. We check sooner if a page names a state, or if someone reports an error. Every page shows the date it was last checked, and your citation should carry that date.
Why do these numbers differ from Angi or HomeAdvisor style ranges?
Those sites usually give you a date but not a method. No named wage source. No coverage chart. No word on what work the price covers. So you cannot check the number, and you cannot tell what job it describes. Our numbers are built from parts we name: a federal wage survey with its year, a coverage chart the maker published, and a store price with the date we read it. That means you can check us. It also means we can be wrong in a way someone can point at and we can fix. That is what the corrections list is for.
What do the basis labels measured, derived and estimated mean?
Measured means we took it straight from a named source. Derived means we did the math on measured numbers, using a rule we spell out. Estimated means it is a judgment call, we explain our thinking, and we mark it as an estimate every time it shows up. There is a fourth tag, open, for a number we have not pinned down yet. An open number never goes on the site.
How do I report an error in the data?
Email [email protected]. Send the number, the page it is on, and the source that says otherwise. If the correction holds up, the page gets fixed and the change goes in the corrections list, along with the source that settled it.