Welcome to Your Green Home Journey
Most contractors sell only what they install. However...
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 (DOE) Home Energy Score. Whether you use the DIY version like our Green Home Predictor or upload an existing audit, both are based on the same underlying modeling logic. A home energy assessment usually sets a solid foundation for a good plan that can be implemented all at once or over time.
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.
- Year built, bedrooms, and dwelling type
- Total conditioned floor area (sq ft)
- Blower door test results (if available)
This sets the baseline. Era-specific construction tells us about insulation defaults, while size determines heating/cooling loads.
This defines your thermal boundary and air barrier tightness. These are the most critical metrics for comfort.
- Attic type (unconditioned, cathedral, flat)
- Insulation level (R-value)
- Roof color and skylights
The attic is the primary site of heat loss in winter and gain in summer due to the Stack Effect.
- Foundation type (slab, basement, crawlspace)
- Floor and wall insulation levels
“An uninsulated basement is like living over a cold cave. You’re heating it whether you want to or not.”
Foundations manage moisture and conduction. Rim joists are often the leakiest part of a home's air barrier.
- Wall construction and siding type
- Insulation levels (check outlets or unfinished areas)
Walls are the largest surface area of your envelope. Adding continuous insulation during re-siding is a "once in a generation" upgrade opportunity.
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.
- System types and fuel sources
- Efficiency (AFUE, SEER, HSPF) or install year
- Duct location and sealing status
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.
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.
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.
- Tank vs Tankless
- Energy Factor (EF/UEF) or age
Water heating is usually the 2nd largest energy expense. Moving to a Heat Pump Water Heater can reduce this cost by 70%.
- Window area per side (N, S, E, W)
- Panes (Single/Double/Triple) and Frame material
Windows are the "zippers" of your thermal coat. They are major sources of radiant heat gain.
- System size (kW) or number of panels
- Orientation and year of install
Solar is the final step: once you've reduced your load with the steps above, solar offsets what's left to reach Net Zero.
🚀 Ready to generate your score?
Visit the GHC's Step1 Audit Tool to enter your data. Then, take that score to
Step 2 to build your roadmap.