The calculator
Run the energy savings & payback calculator
Enter your current annual heating + cooling cost, project type, and current insulation level. The calculator estimates annual savings from your own numbers. No primary source publishes a Denver-specific installed cost, so this tool does not compute a payback figure that requires one — the free in-home estimate gives you the actual project cost to divide against.
Your home + project
A rough estimate is fine here.
According to ENERGY STAR's Seal and Insulate program, “EPA estimates that homeowners can save an average of 15% on heating and cooling costs (or an average of 11% on total energy costs) by air sealing their homes and adding insulation in attics, floors over crawl spaces and basements.”
How this works
How does the energy savings & payback calculator work?
Savings percentage by project type and current state uses conservative Denver-metro retrofit ranges, calibrated around ENERGY STAR's cited Climate Zone 5 heating-and-cooling figure, applied against the annual heating and cooling cost you enter.
No primary source publishes a Denver-specific installed cost per project type, so this tool does not compute a payback period or a 5- or 10-year net figure — both would require dividing by a cost this site cannot source. The free in-home estimate gives you the actual project cost; divide it into the savings range above for your own payback number.
According to the International Energy Conservation Code, the 2021 IECC sets a minimum ceiling insulation R-value of R-60 in Climate Zone 5 under Table R402.1.3, and Section R402.2.1 allows R-49 to satisfy that requirement only where the full height of uncompressed R-49 insulation extends over the wall top plate at the eaves.
Get a quote
Get a Quote Based on Your Numbers
We've Got It. Here's What Happens Next.
We've got your info and are routing it to a local pro. When they call, here's what to look for in the quote you receive: (1) R-value target — the 2021 IECC sets a ceiling minimum of R-60 in Climate Zone 5 (Table R402.1.3); R-49 qualifies only where uncompressed insulation extends full-height over the top plate at the eaves. (2) Air sealing scope — insulation and air sealing work together; sealing the leaks first is what lets the insulation do its job. If a quote skips both, get another quote. The federal IRA Section 25C tax credit ended December 31, 2025, and Colorado's HEAR single-family program is now closed for both Region 1 (the Front Range) and Region 2. Xcel Energy programs are the ones still paying on Denver-area insulation projects in 2026.
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Frequently asked
What do Denver homeowners ask about this calculator?
Should I use this calculator if my home was built after 2010?
Possibly — but interpret the output cautiously. Post-2010 Denver homes were built to the code edition in force at the time, which set a lower ceiling minimum than the R-60 the 2021 IECC requires — so a newer home can be code-legal as built and still sit short of today's target. Most calculator scenarios assume pre-1990 baselines and may overstate the project value for newer homes. If your bills are normal and your comfort is fine, the honest answer is usually: hold the money. The 10-15 year mark is when even code-compliant homes start showing settled batts.
Do you handle new construction insulation?
We focus on retrofit insulation for existing Denver homes. New construction insulation typically goes through your general contractor or builder, and the process is different — pricing structures, code compliance steps, and project timing all work differently for new builds. If you're working on a new build, we can refer you to a partner with new-construction experience.
Why won't this tool give me a payback period?
Because payback is project cost divided by annual savings, and no primary source publishes a Denver-specific installed cost per project type. Printing a payback figure would mean inventing the cost half of that division. The savings half is real — it's your own entered utility cost times a modeled percentage — so this tool stops there and routes you to the free in-home estimate for the actual cost.
Does this account for insulation degradation over time?
Loose-fill cellulose settles 10-20% over its lifetime, reducing effective R-value. The calculator's annual savings figures assume an average across the project's lifetime, not peak first-year performance. That's why R-60 is the target rather than R-49 — R-60 is the code requirement, and the extra depth leaves headroom for settlement.
What if energy prices go up?
Then your dollar savings rise proportionally, since this tool applies a percentage to your entered annual cost. Conversely, if you switch to a heat pump (more efficient than gas), absolute dollar savings shrink even though percent savings stays similar.
Do rebates change the savings shown here?
No — rebates affect the cost side of the payback math, not the savings side. Xcel's insulation and air sealing rebates are capped per measure, are paid by check after your application is approved, and require an Xcel participating contractor. Get your project cost from the free in-home estimate, then apply rebates to that number.
What if I plan to sell before payback completes?
Some studies show insulation upgrades return a meaningful share of project cost at sale via higher home value, but that's market-dependent and this tool doesn't estimate it. Before scoping a project, ask whether you'll be in the home long enough for the energy savings alone to matter to you.