Energy Assessment vs Energy Audit: The Difference

We hear the question at least a few times a month. A homeowner calls and asks for an "energy audit." Sometimes they say "home energy audit." Sometimes they ask if we do "blower door tests." They found the term on a utility website, or a neighbor mentioned it, or they read an article about reducing heating costs and the article said "start with an energy audit."

The terminology is confusing, and it is not the homeowner's fault. The home performance industry uses "assessment," "audit," "evaluation," "inspection," and "diagnostic" almost interchangeably in marketing materials, even though these words describe different things.

Here is what each term actually means, what our free energy assessment includes, when diagnostic testing happens, and how to figure out which one you actually need.

What People Mean When They Search for "Energy Audit"

When a homeowner types "energy audit" into a search engine, they are usually looking for one of three things:

1. Someone to tell them where their home is losing energy - the most common intent. They know their heating bills are high or their house is uncomfortable, and they want a professional to identify the problems
2. A formal diagnostic test with equipment - they have heard about blower door tests or infrared cameras and think that is the starting point for any energy improvement work
3. A requirement for a rebate or incentive program - some programs require an audit before work begins. Efficiency Maine's programs have specific requirements depending on the scope of work

All three are legitimate needs, and they all lead to different processes. Understanding the difference saves time and helps you get to the right starting point.

Energy Assessment: What We Offer (Free)

At Horizon Homes, we offer a free home energy assessment. This is a visual walkthrough of your home performed by one of our experienced energy advisors. It takes 30 to 60 minutes depending on the size and complexity of your house, and it costs nothing.

What Happens During the Assessment

Your advisor walks through the entire home with you. Here is what they look at:

The attic. Insulation type, depth, and condition. Visible air sealing gaps around penetrations - plumbing vents, electrical wires, recessed lights, the attic hatch. Signs of moisture, mold, or pest activity. Whether the attic ventilation is adequate.

The basement and crawlspace. Rim joist condition and insulation. Sill plate gaps. Foundation wall insulation (or lack of it). Moisture issues, standing water, or humidity indicators. The condition of any existing insulation.

Exterior walls. Visual assessment of wall construction era and type. Checking for evidence of existing insulation (or absence of it). In some cases, using a borescope to look inside the wall cavity through a small hole behind baseboard trim or in a closet.

The heating system. Age, type, efficiency rating, and general condition of your boiler, furnace, or heat pump. Distribution type (baseboard, radiant, forced air, mini-splits). Thermostat type and settings.

Comfort issues. Your advisor asks about specific problems - which rooms are cold, where you feel drafts, whether ice dams form, whether certain areas are always too hot or too cold. Your observations about the house are valuable data points.

What You Get

After the walkthrough, you receive a clear picture of:

• Where your home is losing energy and why
• Which improvements would have the most impact on comfort and energy costs
• Approximate costs and savings for recommended work
• Which Efficiency Maine rebates apply to your situation (amounts are income-dependent)
• A prioritized plan if you cannot do everything at once

No equipment is deployed during the assessment. No blower door, no infrared camera, no duct blaster. The assessment is a professional evaluation based on visual observation and 20+ years of experience working on Maine homes.

This is intentional, and here is why.

Why We Do Not Use Equipment for the Free Assessment

Some companies advertise a "free energy audit" that includes blower door testing and infrared imaging as part of their sales process. We take a different approach, and there is a practical reason for it.

A blower door test measures total air leakage by depressurizing the house with a calibrated fan. It tells you how much air is leaking, but not where or which leaks matter most. A house can test at 3,000 CFM50 (common for older Maine homes), and you still need an experienced eye to determine that the biggest opportunities are in the attic hatch, the plumbing chases, and the rim joists.

An experienced energy advisor identifies those priorities in 30 minutes by walking through the house. The visual walkthrough is faster, less disruptive, and gives the homeowner a more practical understanding of their home's problems.

This does not mean diagnostic testing has no value. It does. The difference is when it happens.

When Diagnostic Testing Happens

At Horizon Homes, blower door testing and infrared imaging are used during the actual work - not as a separate billable appointment before the work begins.

Before Work Starts (Baseline)

On the day we begin air sealing and insulation work, we set up a blower door and run a baseline test. This gives us an exact measurement of where the building starts - a CFM50 number that represents total air leakage under standardized conditions. We also use infrared cameras during the blower door test to pinpoint specific leak locations that are not visible to the naked eye.

This baseline test serves two purposes: it confirms our assessment findings and it gives us a target for improvement.

During the Work (Targeting)

While the house is depressurized, our crew can feel and see air movement at specific leak locations. This helps them target air sealing work precisely - focusing time and material where it will have the most impact.

After Work Is Complete (Verification)

We run the blower door test again after finishing the work. The difference between the before and after numbers tells us exactly how much air leakage we reduced. This is our quality assurance step. If the numbers are not where we expect them to be, we investigate and address any remaining leaks before we leave.

This approach means diagnostic testing is not a separate cost or a separate appointment. It is built into the project as a quality control measure. You do not pay for a diagnostic visit and then wait for a separate crew to do the work. The testing and the work happen together.

Formal Energy Audits: When You Actually Need One

There are situations where a formal energy audit - with documented diagnostic testing, a written report, and specific recommendations - is required or beneficial.

Certain rebate programs. Some Efficiency Maine programs require documented testing as part of the project scope. When that is the case, the testing is performed as part of our work and documented according to program requirements. We handle the paperwork and program compliance.

Real estate transactions. Some buyers request a formal energy assessment or audit as part of the home-buying process. This is becoming more common in Maine, especially among buyers who are aware of the energy costs associated with older homes.

Large-scale renovations. If you are planning a major renovation and want a comprehensive energy model before making design decisions, a formal audit with detailed testing may be worthwhile.

For most homeowners trying to figure out "what should I do to make my house more comfortable and lower my heating bills," the free assessment is the right starting point.

Common Questions About Assessments and Audits

"Will you tell me my home's ACH50 number during the assessment?"

ACH50 (Air Changes per Hour at 50 Pascals) is a measurement that comes from a blower door test. Since we do not run a blower door during the free assessment, we cannot give you that number at that stage. We can, and often do, estimate the likely range based on the age, construction type, and visible condition of your home. When we perform the work, you get the actual measured number before and after.

"My neighbor got a free blower door test from another company. Why don't you offer that?"

Some companies use diagnostic testing as a lead generation tool. Our experience is that the visual assessment provides equal or better practical guidance in less time, with less disruption. We would rather spend 45 minutes understanding your home than 90 minutes running a test that confirms what an experienced advisor already identified.

"Is your assessment a real assessment or just a sales pitch?"

Fair question. Our assessment is a genuine evaluation of your home. We identify problems, prioritize them, and estimate costs and savings. If your home does not need work, we will tell you that. If the improvements we recommend are not cost-effective for your situation, we will tell you that too. We have been doing this since 2006, and our reputation depends on giving honest advice - even when the honest advice is "you are fine."

"Do I need an audit to get Efficiency Maine rebates?"

For most insulation and air sealing work, no. Our assessment is sufficient to scope the project and qualify for applicable rebates. Rebate amounts are income-dependent, and we verify your eligibility and apply rebates directly to your invoice. For certain program categories or larger projects, documented testing is required - and we build that testing into the project scope at no additional cost.

The Bottom Line

If you are searching for an "energy audit" because you want to understand where your home is losing energy and what you can do about it, our free energy assessment gives you that answer. No equipment, no disruption, no obligation.

If you need formal diagnostic testing for a specific program, transaction, or project requirement, that testing happens as part of the work itself - not as a separate appointment or charge.

Either way, the first step is the same.

Schedule a free energy assessment with Horizon Homes. We will walk through your home, identify where you are losing energy, and give you a clear plan with costs and available rebates. Thirty to sixty minutes, no cost, no pressure.

Call (207) 221-3221 or book online. Horizon Homes has been serving Greater Portland since 2006 - an Efficiency Maine Top Contractor for 10+ years.