Home Energy Audit Calculator

We estimate annual energy cost by summing the cost of operating each category of home equipment — HVAC, water heating, kitchen appliances, lighting, electronics, and laundry — using DOE/Energy Star wattage and usage data.

HVAC consumption is adjusted by an insulation factor (poor insulation: 1.4×, average: 1.15×, good: 1.0×) reflecting the impact of building envelope on heating and cooling loads. Total cost is also scaled by home size (relative to a 2,000 sqft baseline).

The results show your annual cost by category, your top energy-using appliances, and the highest-leverage upgrades available to you.

A home energy audit is the starting point for any efficiency project. The goal is to understand where your energy goes and where the highest-leverage savings are. For most U.S. homes, that's HVAC and water heating — together they typically account for 55–70% of total energy use.

The envelope (insulation and air sealing) drives HVAC efficiency more than the equipment itself. A leaky, poorly insulated home can use 40% more energy for heating and cooling than a well-sealed equivalent. Improving the envelope is almost always the highest-ROI energy upgrade.

LED lighting is the lowest-effort big win — replacing remaining incandescent bulbs cuts lighting electricity by ~85% and pays back in months. Smart thermostats reduce HVAC energy 8–12% in most homes for $100–$300 of investment. Heat pump water heaters cut water heating energy by 50–60% but require larger upfront investment.

Energy efficiency tax credits under Section 25C can offset 30% of qualifying upgrade costs (up to $3,200/year), making 2026 an excellent year for envelope and equipment upgrades. Many utilities also offer rebates that stack on top of federal credits.