🏡 Step 1 • Get your baseline score

Welcome to Your Green Home Journey

Most contractors sell only what they install. However...

House-as-a-System

Heat, air, and moisture do not stay politely in one place. They move across connected surfaces—not just through furnaces or windows. Therefore, it makes sense to look at the house-as-a-system. A great starting point is the logic behind the Department of Energy's Home Energy Score (HES). Whether you use a DIY energy audit to get started or have an existing professional assessment like a HES, both are based on the same underlying modeling logic where the home is treated as one interconnected system. This assessment is the first step for a good plan that can be implemented all at once or over time.

📌 Start Here: Gather Inputs About The Home

The sections below show you what to collect, why it matters, and how it connects to building science. Open one section at a time as you walk your home. Use a notebook or our Data Collection Form to record your findings first.

📋 Part 1A: About This Home – Basic Snapshot
📋 What You’ll Collect:
  • Project/home name and address or cross streets
  • ZIP code, year built, conditioned floor area, and number of stories
  • Average ceiling height and climate zone, if known
🧠 Why It Matters

This sets the baseline. The home’s age, size, height, and location help estimate heating and cooling loads, likely insulation levels, and the climate conditions the home must perform under.

🔬 Building Science Connection

This helps define the thermal boundary, the volume of conditioned space, and the basic load assumptions used for comfort and retrofit planning.

🏠 Part 1B: Attic & Ceiling – The Top Control Layer
📋 What You’ll Collect:
  • Attic or ceiling type: vented attic, unvented attic, cathedral/vaulted ceiling, finished attic/knee walls, no accessible attic, or unknown
  • Attic insulation level: unknown, none/R-0, low, moderate, or high/R-49+
  • Whether the attic appears air sealed: yes, no, partial, or unknown
🧠 Why It Matters

The attic is often the primary site of heat loss in winter and heat gain in summer due to the Stack Effect. Insulation slows heat movement, while air sealing helps stop conditioned air from escaping into the attic.

🧱 Part 1C: Foundation, Basement & Rim Joists
📋 What You’ll Collect:
  • Foundation type: conditioned basement, unconditioned basement, slab, vented crawlspace, unvented crawlspace, mixed, or unknown
  • Foundation wall insulation level: unknown, none/R-0, some/low, moderate, or high/R-19
  • Whether rim joists appear sealed/insulated: yes, no, partial, or unknown
“An uninsulated basement is like living over a cold cave. You’re heating it whether you want to or not.”
🔬 Building Science Connection

Foundations manage moisture and conduction. Rim joists are often one of the leakiest parts of a home's air barrier, especially in older homes.

🧱 Part 1D: Exterior Walls – The Thermal Envelope
📋 What You’ll Collect:
  • Wall insulation level: unknown, none/R-0, some/low, moderate, or high
  • Notes about wall construction, siding, or known insulation work if available

Walls are the largest surface area of your envelope. Adding continuous insulation during re-siding is a "once in a generation" upgrade opportunity.

Estimating Wall Insulation Defaults

If your home has wood frame construction and no additional wall insulation has been installed since it was built, you can use U.S. Department of Energy defaults based on your home's age and wall thickness.

  • Step 1: Determine Framing. Measure the depth of an exterior door jamb (excluding trim). Approximately 4.5 inches indicates 2x4 framing. Approximately 6.5 inches indicates 2x6 framing.
  • Step 2: Find Your R-Value. Select your region above to update the table, then match your built year and framing size.
Built Year 2x4 Framing 2x6 Framing

Source: U.S. Department of Energy. Learn more or find values for other regions using the Assessor Calculator at homeenergyscore.gov.

🔥 Part 1E: Heating, Cooling & Ducts
📋 What You’ll Collect:
  • Primary heating system type and fuel source
  • Heating and cooling efficiency, if known, or year installed if efficiency is not known
  • Cooling system type, including none, central AC, heat pump, mini-split, or window/room AC
  • Secondary or supplemental systems, such as mini-splits, electric baseboard, wood/pellet stove, window AC, or backup systems
  • Distribution type, duct insulation, duct sealing status, and duct location
🔎 How to Gather It

Look for a label on the furnace, boiler, heat pump, AC condenser, air handler, or mini-split outdoor unit. If you cannot find AFUE, SEER, HSPF, COP, or EER, record the approximate year installed. Taking a photo of the equipment label is often easier than writing everything down.

🧠 Why Ducts Matter

Leaky ducts in an attic can waste 30% of your energy before it even reaches your rooms. Sealing ducts is often higher ROI than replacing the furnace itself.

📊 Default Heating Efficiency by Year Installed

If the homeowner does not know the exact efficiency, our tool can use default values based on the approximate install year. These are planning assumptions only and may need contractor verification.

System Year Installed / Type Default Efficiency Confidence Notes
Gas Furnace
(AFUE)
Pre-1980 60% Low Natural draft, very inefficient
1980–1991 68% Med Pre-federal standard
1992–2005 78% High Federal minimum
2006–2012 80% High Standard non-condensing
2013–2018 90% Med Mix of condensing + standard
2019–present 95% High Predominantly condensing
Gas Boiler
(AFUE)
Pre-1980 65% Low Cast iron, standing pilot
1980–1995 75% Med Mid-efficiency
1996–2010 82% High Standard baseline
2011–2018 88% Med Some condensing
2019–present 92% High Condensing common
Oil Furnace / Boiler
(AFUE)
Pre-1980 60% Low Older oil equipment
1980–1995 70% Med Improved but still dated
1996–2010 80% High Standard baseline
2011–present 85% Med Higher-efficiency oil systems
Electric Resistance Heat Baseboard / electric furnace 100% High Site efficiency only, not source efficiency
Heat Pump (Air-Source) Pre-2006 HSPF 6.8 (~COP 2.0) Low Early units
2006–2014 HSPF 7.7 (~COP 2.3) Med Federal minimum
2015–2022 HSPF 9.0 (~COP 2.6) High Better units
2023–present HSPF 10+ (~COP 3.0) High Cold-climate capable
Mini-Split / Cold-Climate Heat Pump Pre-2015 HSPF 8.5 / COP 2.5 Med Earlier mini-split generation
2015–2020 HSPF 10 / COP 3.0 High Improved performance
2021–present HSPF 11–13 / COP 3.2–3.8 High Cold-climate models common
Wood / Pellet Wood stove (old) 50% Low Older equipment
Wood stove (EPA) 70% Med Cleaner-burning stove
Pellet stove 75–85% Med Varies by model
💡 How This Helps the Step 1 Audit

Many homeowners know roughly when their equipment was installed, even if they do not know AFUE, SEER, or HSPF. That makes install year a practical way to create a first-pass efficiency estimate for budgeting and retrofit planning.

🚿 Part 1F: Hot Water Systems
📋 What We’re Asking:
  • Water heater type: gas storage, electric storage, heat pump water heater, tankless, indirect/boiler, or other
  • Fuel: natural gas, electric, propane, oil, boiler-connected, or unknown
  • Energy Factor / Uniform Energy Factor (EF/UEF), if known, or year installed

Water heating is usually the 2nd largest energy expense. Moving to a Heat Pump Water Heater can reduce this cost substantially in many homes.

As with heating and cooling equipment, a clear photo of the water heater label is often the easiest way to capture the useful information.

⚡ Part 1G: Electrical Panel – Electrification Readiness
📋 What You’ll Collect:
  • Panel status: adequate/modern, older but functional, possible upgrade needed, unsafe/needs electrician, or unknown
  • Service amps and main breaker rating, if visible
  • Whether panel space and open 240V space appear available
  • Panel photo and main breaker/panel label photo
⚠️ Safety Note

Do not remove the panel cover or touch wiring. Only observe what is visible from the outside or from the normal hinged panel door. If anything looks damaged, overheated, loose, wet, or unsafe, mark it for electrician review.

🧠 Why It Matters

Electrification may add future loads such as heat pumps, heat pump water heaters, induction ranges, EV chargers, batteries, or solar equipment. The Step 1 audit does not replace an electrician’s load calculation, but it helps flag whether electrical readiness should be reviewed early.

🪟 Part 1H: Windows – Area, Panes & Radiation
📋 What You’ll Enter:
  • Approximate window area as a percentage of wall area
  • Window type: single pane, single + storms, double pane clear, double pane low-E, triple pane, or mixed/unknown
  • Notes about unusual window conditions, if helpful

Windows are the "zippers" of your thermal coat. They can be major sources of heat loss, comfort problems, and radiant heat gain.

🌬️ Part 1I: Ventilation, Appliance Clues & Moisture
📋 What You’ll Collect:
  • Mechanical ventilation: none known, bath fans only, kitchen exhaust, HRV/ERV, fresh-air duct, other, or unknown
  • Visible combustion appliances: gas furnace, gas boiler, gas water heater, gas fireplace, gas range/oven, wood/pellet stove, none known, or unknown
  • Moisture / IAQ concerns: musty basement, mold concern, condensation, ice dams, poor bath/kitchen exhaust, none observed, or notes
⚠️ Observation Only

This is not a combustion safety test. Do not test, adjust, or diagnose combustion equipment yourself. The goal is simply to note visible appliances and moisture/ventilation clues so the plan can flag what a qualified professional may need to verify before air sealing, insulation, or electrification work.

🧠 Why It Matters

A tighter home can be more comfortable and efficient, but it also needs moisture control, good exhaust, and safe appliance sequencing. These observations help the plan avoid treating insulation, ventilation, and equipment as separate silos.

📸 Part 1J: Utility Signal, Photos & Priorities
📋 What You’ll Collect:
  • Optional electric usage: annual kWh or monthly average, or a bill photo
  • Optional gas/fuel usage: annual therms/gallons or monthly average, or a bill photo
  • Photos: front exterior, other sides, attic/insulation, rim joist, foundation wall, equipment labels, electrical panel, windows, and problem areas
  • Homeowner priorities: high bills, comfort, electrification, health/IAQ, resale, contractor bid, rebate readiness, timing, urgency, and budget sensitivity
🧠 Why It Matters

Utility use can help reality-check the model later, while photos reduce guesswork. Homeowner priorities do not change the physical facts of the home, but they do help shape the next-step pathway, contractor conversation, and budget planning.

☀️ Part 1K: Solar / EV / Net-Ready
📋 What We’re Asking:
  • Solar status: existing solar, solar planned/interested, no solar, or unknown
  • System size or annual production if known
  • EV charger present or planned, battery present/planned, or interest in a net-zero/net-ready pathway

Solar helps close the gap between a high-performance electric home and a net-zero or net-ready home. First reduce the load with envelope and equipment improvements; then solar can offset what remains.

🚀 Ready to generate your score?
Visit the GHC's Step 1 Audit Tool to enter your data. Then, take that score to Step 2 to build your roadmap.