How to Perform a DIY Home Energy Audit and Cut Your Utility Bills

Are your energy bills climbing higher each month with no obvious explanation? You’re not alone. Many homeowners are surprised to learn how much energy their home wastes every day—often through hidden air leaks, outdated appliances, poor insulation, or inefficient heating and cooling systems. These seemingly small issues can add up to hundreds of dollars lost each year.

The good news? You can take control with a simple, do-it-yourself home energy audit. Whether you're aiming to make your home more eco-friendly or just want to lower your utility bills, an energy audit helps you identify problem areas and prioritize cost-effective improvements.

This guide walks you through the process of conducting a basic home energy audit. From inspecting windows and doors to assessing insulation and lighting, you’ll gain the tools to uncover hidden energy drains and take smart steps toward a more energy-efficient home.

What Is a Home Energy Audit?

A home energy audit, also known as a home energy assessment, is a systematic review of how energy flows through your home. The goal is to pinpoint areas where energy is being lost or used inefficiently—and then identify practical ways to correct those issues. It helps you:

• Identify air leaks and energy loss zones
• Evaluate the efficiency of your insulation, windows, and HVAC system
• Reduce unnecessary energy use and lower monthly utility bills
• Make smarter, more cost-effective decisions about upgrades and repairs

An energy audit acts like a “check-up” for your house, helping you prioritize improvements that will give you the most return on your investment.

Professional energy auditors typically use specialized equipment—such as blower doors and infrared cameras—to assess a home’s performance. They may also provide a detailed report with recommendations and projected energy savings. You can learn more about professional assessments from the U.S. Department of Energy.

But the great news is: even without advanced tools, a DIY home energy audit can still yield big benefits. With just a few simple checks, you can discover many of the same inefficiencies—and fix them on your own.

In the next sections, we’ll break down how to perform your own audit step-by-step, starting with one of the biggest energy wasters in most homes: air leaks.

1. Check for Air Leaks

Even a small draft can have a big impact on your monthly energy bill. According to the U.S. Department of Energy, air leaks can account for up to 30% of a home’s heating and cooling costs. The most common problem areas include windows, exterior doors, baseboards, fireplace dampers, electrical outlets, attic hatches, and anywhere different building materials meet.

One simple method for detecting leaks is the “smoke test”: close all doors and windows, turn off HVAC systems and fans, then light an incense stick or candle near suspect areas. If the smoke wavers or is drawn inward, you’ve likely found a leak.

Quick Fix: Seal air leaks using weatherstripping for movable joints like doors and windows, and use caulk or expandable foam for stationary gaps. For doors with noticeable under-door drafts, installing a door sweep is an easy and effective solution.

Plugging these leaks not only improves comfort, but also reduces the load on your HVAC system—saving you energy and extending the life of your equipment.

2. Inspect Insulation

Insulation acts as your home’s thermal barrier, keeping conditioned air inside and outdoor air out. Poor or outdated insulation is one of the most overlooked causes of energy waste. If your home was built before the 1980s, there’s a good chance your insulation doesn't meet modern standards.

Attics, crawl spaces, walls, and basements are the most important places to check. In the attic, ensure the insulation fully covers the floor joists and is evenly distributed. You can measure its effectiveness by checking its R-value—a rating of thermal resistance.

Upgrade Tip: If your insulation is inadequate or compressed, consider upgrading to modern materials like blown-in cellulose, mineral wool, or spray foam. Spray foam, while more costly upfront, offers superior air sealing in addition to insulation and can significantly reduce energy loss through attics and walls.

Don’t forget to also insulate attic access points and around recessed lighting fixtures—two commonly missed spots.

3. Evaluate Heating and Cooling Systems

Your home’s HVAC (heating, ventilation, and air conditioning) system is often the largest energy consumer in the house—sometimes accounting for over 40% of total energy use. Start your audit by inspecting air filters, vents, and ductwork. Dirty filters restrict airflow, making your system work harder and consume more energy. Replace or clean filters every 1–3 months depending on usage and filter type.

Next, examine visible ductwork for holes, gaps, or disconnected segments, especially in unconditioned spaces like basements, attics, or garages. Duct leaks can result in up to 30% energy loss. Sealing and insulating ducts can significantly improve overall HVAC performance.

If your heating or cooling system is more than 15 years old, it may be time to explore high-efficiency replacements. Modern ENERGY STAR-certified HVAC systems use significantly less energy while offering better performance.

Maintenance Tip: Schedule a professional tune-up annually to check refrigerant levels, inspect electrical connections, calibrate your thermostat, and ensure peak efficiency. If your thermostat is outdated, consider upgrading to a programmable or smart thermostat for even more control and savings.

4. Check Lighting Efficiency

Lighting accounts for about 10% of the average home's electricity usage, and using outdated bulbs can drive those costs up unnecessarily. Traditional incandescent bulbs are extremely inefficient—wasting up to 90% of their energy as heat rather than light.

By switching to ENERGY STAR-certified LEDs, you can reduce your lighting energy use by as much as 75%. LEDs also last 15 to 25 times longer than incandescent bulbs, making them a smart investment for both energy savings and long-term convenience.

LEDs are now available in a variety of color temperatures and styles, including dimmable and smart bulbs that integrate with home automation systems. Replacing your most frequently used light fixtures—such as kitchen, bathroom, and outdoor lights—can yield immediate savings on your electricity bill.

5. Examine Major Appliances

Appliances account for a significant portion of home energy use, especially refrigerators, dishwashers, clothes washers and dryers, and water heaters. If your appliances are more than 10–15 years old, they may be consuming far more energy than newer models.

When it's time to upgrade, look for appliances bearing the ENERGY STAR label. These products are independently certified to use less energy without sacrificing performance. For example, ENERGY STAR refrigerators use up to 15% less energy than non-certified models, while ENERGY STAR dishwashers can save over 3,800 gallons of water over their lifetime.

Also consider how and when you use your appliances. Running full loads in your dishwasher and washing machine, using cold water when possible, and air-drying clothes can cut your energy usage even further.

Phantom Power Tip: Many electronics and small appliances continue to draw power even when turned off—a phenomenon known as “phantom load” or “vampire power.” Unplug devices that aren’t frequently used, or invest in smart power strips that automatically cut off power when devices go into standby mode.

6. Use Smart Thermostats and Timers

Heating and cooling are among the biggest contributors to residential energy consumption, but smart home technology can make it easier than ever to manage those costs. Smart thermostats—like those from Nest, ecobee, or Honeywell—automatically adjust your HVAC system based on your schedule, habits, and even the weather.

Homeowners can save up to 10% a year on heating and cooling just by adjusting their thermostat 7°–10°F for 8 hours a day. Smart thermostats take the guesswork out of this process by learning your preferences and making real-time adjustments.

Timers and smart plugs also help reduce energy waste by turning off lights or electronics during inactive periods. For example, setting your water heater, coffee maker, or outdoor lighting on a schedule can help avoid unnecessary electricity use.

Pairing these smart tools with an optimized energy plan from Ladybug Energy can further boost your savings and give you more control over your home’s electricity use.

When to Call in the Pros

While a DIY home energy audit can uncover many common issues, there are times when calling in a certified professional is the best move—especially if you want a thorough, data-backed report on your home's energy performance.

Professional energy auditors use specialized tools such as blower door tests, infrared thermographic cameras, and duct leakage testers to detect hidden air leaks, insulation voids, and thermal inefficiencies that may be missed during a basic visual inspection. These diagnostics help create a full picture of how your home uses and loses energy.

The auditor may also provide a comprehensive report with prioritized recommendations and estimates of potential energy savings for each fix—giving you a clear roadmap for upgrades that will deliver the most value.

To ensure quality results, hire an auditor certified by either the Residential Energy Services Network (RESNET) or the Building Performance Institute (BPI). These organizations maintain national standards for training, testing, and performance, and their certified professionals are recognized by utilities and government rebate programs.

In many states, your local utility company may offer rebates or even free professional energy audits. Check with your provider or visit the Database of State Incentives for Renewables & Efficiency (DSIRE) to explore available incentives.

Bonus Tips for Lower Energy Bills

Small habits and upgrades can go a long way in reducing your home’s overall energy consumption. Here are a few high-impact strategies to consider:

• Install ceiling fans to improve airflow in both summer and winter. Set them to spin counterclockwise in the summer to create a breeze and clockwise in the winter to circulate warm air that rises to the ceiling.
• Use thermal or blackout curtains to block heat gain in the summer and reduce heat loss in the winter. This is especially useful for drafty windows or older homes with single-pane glass.
• Swap out standard showerheads and faucets for WaterSense-labeled low-flow models. These reduce hot water use—cutting energy costs related to water heating without sacrificing performance.
• Track your energy usage in real time with a home energy monitor like the Sense or Emporia Vue. These devices can help you identify energy hogs and better understand your household consumption patterns.

A basic home energy audit is a simple and powerful step toward reducing waste and cutting costs. With a few hours and some attention to detail, you can boost your home’s comfort and slash your monthly energy bill.
Once your home is energy-efficient, make sure your electricity plan is too. Use Ladybug Energy to compare rates, switch providers, and save money—without the stress.