How to Perform a Home Energy Audit: Step-by-Step Checklist

You know something is wrong when your utility bill shows up and the number makes you flinch. You keep the thermostat reasonable. You turn off lights when you leave rooms. Yet the costs keep climbing. The problem is not always what you can see. Hidden air leaks, poor insulation, and inefficient appliances drain energy and money without giving you any clue they exist.

A home energy audit helps you find these silent money drains. You walk through your home with a purpose. You check for drafts, inspect insulation, test appliances, and identify where your heating and cooling escapes. Most of these checks require nothing more than your time and a few basic tools.

This guide walks you through a complete DIY home energy audit from start to finish. You will learn how to prepare, what to look for in each room, which problems to tackle first, and when to call in a professional. By the end, you will have a clear action plan to cut your energy waste and lower your monthly bills.

Why a home energy audit matters

Your home loses money every day through inefficiencies you cannot see. The average American household spends more than $2,000 annually on energy bills, and the Department of Energy estimates that 10 to 20 percent of that cost comes from air leaks alone. When you add outdated appliances, poor insulation, and inefficient heating systems, the waste multiplies. Understanding how to perform a home energy audit gives you the power to stop these losses and redirect that money back into your budget.

The financial impact

Every draft around a window, every gap in your attic insulation, and every outdated appliance adds to your monthly expenses. Sealing air leaks can save you $100 to $400 per year on heating and cooling costs. Upgrading to modern LED lighting cuts lighting costs by 75 percent compared to traditional incandescent bulbs. When you insulate your attic properly, you can reduce heating bills by up to 30 percent in cold climates. These savings compound year after year, turning a few hours of audit work into thousands of dollars back in your pocket over the life of your home.

Beyond the bills

Comfort matters as much as cost. Drafty rooms that never quite reach the right temperature make your home unpleasant to live in. Poor ventilation traps stale air, odors, and indoor pollutants that affect your health and sleep quality. An energy audit reveals these problems and shows you exactly where your home fails to maintain consistent temperatures. When you fix the leaks and improve airflow, your heating and cooling systems work less while delivering better results.

A well-sealed, properly insulated home stays comfortable in every season without forcing your HVAC system to run constantly.

The environmental impact also deserves attention. Wasted energy means power plants burn more fuel to meet demand. Reducing your home's energy consumption lowers your carbon footprint without requiring any lifestyle sacrifices.

Step 1. Get ready and gather data

Before you start walking through your home, you need to establish a baseline. Preparation separates a productive audit from a wasted afternoon. When you know what to look for and have your data organized, you spot problems faster and build a clearer picture of your home's energy profile. This first step takes 30 to 45 minutes but saves hours of confusion later.

Collect your utility bills

Pull your last 12 months of utility bills for electricity, natural gas, and any other heating fuels you use. These bills show your consumption patterns across seasons and reveal which months drain your wallet most. Look for unusual spikes that might indicate a specific problem, like a failing water heater or HVAC system struggling during extreme weather. Most utilities now provide online access to historical usage data, making this step quick and painless.

Calculate your average monthly cost and identify your peak usage months. This baseline gives you a target to beat after you implement your fixes. You can also compare your consumption to similar homes in your area using the utility company's comparison tools if they offer them.

Create your audit checklist

When you perform a home energy audit, you need a systematic approach. Use this checklist to guide your inspection room by room:

• Windows and doors: Check for drafts, damaged weatherstripping, broken seals
• Attic and insulation: Measure depth, look for gaps, check vapor barriers
• Basement and crawl spaces: Inspect foundation, rim joists, exposed pipes
• HVAC system: Note age, filter condition, ductwork condition
• Water heater: Check age, insulation, temperature setting
• Appliances: List age and energy ratings for major appliances
• Lighting: Count non-LED bulbs and fixtures
• Electrical outlets and switches: Mark locations on exterior walls

A detailed checklist prevents you from missing critical problem areas and helps you track improvements over time.

Print this list or save it on your phone. Bring a notepad, flashlight, and camera to document what you find.

Step 2. Find leaks and insulation gaps

Air leaks and missing insulation represent the biggest energy drains in most homes. When you perform a home energy audit, these areas deserve your closest attention because fixing them delivers the highest return on your investment. A single afternoon spent tracking down drafts and checking insulation can reveal problems that cost you hundreds of dollars every year. The methods described here work for any home type, from new construction to century-old houses.

Test for air leaks

Start your leak detection on a windy day when temperature differences between inside and outside air make drafts easier to spot. Close all windows, exterior doors, and your fireplace damper. Turn off your HVAC system so it does not interfere with airflow patterns. Light an incense stick or hold a damp hand near potential leak points to feel air movement.

Check these common leak locations systematically:

• Window and door frames: Run your incense stick along all edges where frames meet walls
• Electrical outlets and switches: Test every outlet on exterior walls by removing the cover plate
• Baseboards: Check where flooring meets walls, especially on outside walls
• Attic hatch: Hold the incense stick around the entire perimeter of the access panel
• Recessed lighting: Look for gaps around fixtures in ceilings below unconditioned attics
• Plumbing penetrations: Inspect where pipes enter through floors, walls, or ceilings
• Dryer vents and exhaust fans: Verify dampers close completely when not in use

Sealing the leaks you find today prevents conditioned air from escaping and cuts your heating and cooling costs by 10 to 20 percent immediately.

Check insulation levels

Your attic needs your first attention because heat rises and escapes through inadequate ceiling insulation faster than anywhere else. Climb into your attic with a flashlight and tape measure. Measure the depth of existing insulation between joists. Most climate zones require R-30 to R-49 insulation, which translates to 10 to 16 inches of fiberglass or cellulose. If you see ceiling joists, you need more insulation.

Inspect wall insulation by turning off power to an outlet on an exterior wall, removing the cover plate, and using a thin stick or wire to probe the wall cavity. Resistance indicates insulation exists, but this method cannot tell you if the cavity is completely filled. Look for insulation around your water heater, exposed pipes in unconditioned spaces, and basement or crawl space walls.

Step 3. Assess systems, lighting, and appliances

Your heating, cooling, and major appliances account for 60 to 70 percent of your home's total energy consumption. When you learn how to perform a home energy audit, examining these systems reveals the most expensive inefficiencies hiding in plain sight. A furnace that runs constantly, a water heater set too high, or phantom power drains from old electronics waste hundreds of dollars annually. This step requires you to evaluate each system's condition, age, and efficiency to determine which upgrades will deliver the biggest savings.

Inspect your HVAC system

Check your furnace or air conditioner's age by locating the manufacturer's label on the unit. Systems older than 15 years operate at significantly lower efficiency than modern equipment. Replace your air filter if it looks dirty or clogged. A dirty filter forces your system to work harder and increases energy consumption by 5 to 15 percent. Inspect accessible ductwork for disconnected joints, holes, or dust streaks that indicate air leaks. Seal any gaps you find with mastic sealant or metal-backed tape, not standard duct tape which deteriorates quickly.

Test your thermostat by setting it to a specific temperature and waiting to see if your system maintains that setting accurately. A malfunctioning thermostat causes your HVAC to cycle improperly and waste energy.

Check your water heater

Find the yellow EnergyGuide label on your water heater to check its efficiency rating and age. Water heaters typically last 8 to 12 years, and older units waste substantial energy compared to modern models. Touch the tank's surface. If it feels warm, the unit lacks adequate insulation and loses heat continuously. Consider adding an insulation blanket rated R-10 or higher to reduce standby heat loss. Check your temperature setting using the dial on the unit. Most homes set water heaters too high. Lowering the temperature to 120 degrees Fahrenheit saves energy without sacrificing comfort.

Evaluate lighting efficiency

Walk through every room and count how many bulbs you still have that are not LED. Incandescent and CFL bulbs waste energy as heat and cost significantly more to operate. Create a replacement list prioritizing the fixtures you use most frequently. LED bulbs use 75 percent less energy than incandescent bulbs and last 25 times longer, making them the clear choice for every socket in your home.

Switching just five frequently-used light fixtures to LED saves you $75 per year in electricity costs.

Test major appliances

Document the age and model of your refrigerator, dishwasher, washing machine, and dryer. Appliances manufactured before 2000 consume two to three times more energy than current Energy Star models. Plug electronics into a power strip and turn it off when devices are not in use to eliminate phantom loads that draw power 24 hours per day. Your entertainment center, computer equipment, and phone chargers all consume electricity even when switched off, adding $100 to $200 annually to your electric bill.

Step 4. Prioritize fixes and next steps

You now have a complete picture of your home's energy problems. The next challenge involves deciding which fixes to tackle first and which require professional help. Not all energy improvements deliver equal returns. When you rank your findings by cost versus impact, you focus your time and budget on changes that save the most money fastest. This prioritization strategy ensures you see immediate results on your utility bills while building momentum toward larger projects.

Rank problems by impact and cost

Start with the no-cost and low-cost fixes that deliver quick wins. Adjust your water heater temperature, replace air filters, seal obvious air leaks with caulk, and swap out incandescent bulbs for LEDs. These changes cost less than $100 total but can reduce your energy bills by 10 to 15 percent immediately. Move next to mid-range improvements like adding attic insulation, weatherstripping doors and windows, and installing programmable thermostats. These projects cost $200 to $1,000 but typically pay for themselves within two to three years through lower heating and cooling costs.

The best energy improvements pay for themselves through savings within five years or less.

Use this priority framework to organize your fixes:

Priority	Action	Typical Cost	Annual Savings
High	Seal air leaks	$50-$150	$100-$400
High	Add attic insulation	$400-$800	$200-$600
Medium	LED lighting upgrade	$50-$200	$75-$150
Medium	Water heater insulation	$30-$60	$40-$100
Low	New appliances	$1,500-$8,000	$100-$300

Decide DIY vs professional help

Handle air sealing, insulation checks, and lighting upgrades yourself if you feel comfortable working in attics and crawl spaces. Schedule a professional inspection for HVAC system repairs, electrical work, or when your DIY audit suggests problems you cannot fully diagnose. Professional audits using blower door tests and thermal imaging reveal hidden issues that basic methods miss.

Bringing your audit together

You now understand how to perform a home energy audit from start to finish. Your checklist reveals where your home wastes energy, your priority list shows which fixes deliver the biggest savings, and your action plan gives you a clear path forward. Start with the quick wins that cost little but save immediately. Work through your medium-priority items as budget allows. Track your utility bills month by month to measure your progress and confirm your savings.

One solution you might not have considered during your audit addresses both energy efficiency and comfort in a single upgrade. A whole house fan pulls cool evening air through your home while exhausting hot attic air, cutting cooling costs dramatically without the expense of running air conditioning. Explore modern whole house fans to see how this proven technology fits into your energy-saving strategy and delivers comfort throughout your home.