The calculator
Run the energy savings & payback calculator
Enter your current annual heating + cooling cost, project type, and current insulation level. The calculator estimates project cost, annual savings, payback period, and long-term net using Denver-metro 2026 pricing and the alive Xcel rebate stack.
Your home + project
Roughly 50-65% of your annual utility bill in Denver. Conservative estimate is fine.
According to the Department of Energy, “adequate insulation and air sealing can reduce heating and cooling costs by 10% to 20% in typical homes.”
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 from the Department of Energy's insulation guidance and ENERGY STAR's Climate Zone 5 efficiency benchmarks. Project cost ranges use 2026 Denver-metro contractor pricing.
Payback math: project cost (or rebate-adjusted cost) divided by annual savings = years to break even. After payback, every dollar of savings goes in your pocket. The 5- and 10-year net figures show cumulative savings minus the rebated project cost.
Calibrated as of May 2026. Real-world payback varies with utility rate changes, weather, and home-specific factors not captured by the inputs.
According to the Xcel Energy, “homes participating in their Whole Home Efficiency program save an average of 15-25% on annual heating and cooling costs.”
Get a quote
Get a Quote Based on Your Numbers
30 seconds to fill out. We'll send your inputs along with the quote request so the contractor knows what you've already calculated.
We've Got It. Here's What Happens Next.
We've got your info. A local pro is reviewing it now. Expect a call within a few hours, or by tomorrow at the latest. While you wait, here's what to look for in the quote you receive: (1) R-value target — current Colorado code is R-49 to R-60 for attics, anything less is under-spec. (2) Air sealing scope — insulation alone does nothing if air leaks aren't sealed first. (3) Rebate handling — Xcel rebate paperwork should be handled for you, not by you. (The federal IRA Section 25C credit expired in 2025 and Colorado HEAR closed for the Front Range — Xcel programs are now the active rebate stack.) (4) Removal scope — pre-1990 homes often need old insulation removed before new install. If a quote skips all four, get another quote.
Related guides
Related services and calculators
According to the ENERGY STAR, “air sealing alone — before insulation upgrades — can reduce energy bills by up to 15% in older homes.”
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 recent code, so 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 is the payback range so wide?
Real-world payback depends on factors not in the inputs: weather variation year to year, utility rate changes, your specific HVAC equipment efficiency, and the actual install quality. The range communicates that uncertainty honestly. The midpoint is the most likely outcome; the high end accounts for cost-side surprises and the low end for performance-side surprises.
Does this account for insulation degradation over time?
Loose-fill cellulose settles 15-20% 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 retrofit (over R-49 minimum) is recommended — it leaves headroom for settlement.
What if energy prices go up?
Then payback gets faster. The calculator uses your current annual heating + cooling cost as the baseline; if rates rise, your savings rise proportionally and payback shortens. Conversely, if you switch to a heat pump (more efficient than gas), absolute dollar savings shrink even though percent savings stays similar.
Why is the rebate-adjusted payback faster?
Because the project cost is lower after the Xcel Insulation and Air Sealing Rebate plus the Whole Home Efficiency Bonus (when 3+ measures bundle). Lower project cost means fewer years of savings needed to break even. Rebates don't change the savings — they change the math on the cost side.
What if I plan to sell before payback completes?
Then you don't recoup the full project cost via energy savings. Some studies show insulation upgrades return 70-80% at sale via higher home value, but that's market-dependent. Before scoping a project, ask whether you'll be in the home for at least the rebated payback period.