Sources
Sourced or it doesn't ship. Every lesson lists the sources behind it, and every source is listed here with the lessons that use it. Where sources disagree, lessons give the range and say so.
Lessons move from draft to fact-checked to reviewed. Only fact-checked or reviewed lessons publish. Lessons touching electricity, structure, combustion, gas, sewage or drinking water also need a second reviewer with trade or engineering background.
energy
- Energy Saver, US Department of Energy (archived copy; the page was removed from energy.gov in mid-2026)
- Estimating Appliance and Home Electronic Energy Use, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026)
- Off-Grid or Stand-Alone Renewable Energy Systems, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026)
- Homeowner's Guide to Solar, US Department of Energy, Solar Energy Technologies Office
- Small Wind Guidebook, US Department of Energy, WINDExchange Lessons: 28
- Microhydropower Systems, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026) Lessons: 28
- Heat Pump Systems, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026)
- Wood and Pellet Heating, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026) Lessons: 31
- Water Heating, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026) Lessons: 33
- Heat Pump Water Heaters, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026)
- Solar Water Heaters, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026) Lessons: 33
- PVWatts Calculator, National Laboratory of the Rockies (formerly the National Renewable Energy Laboratory, NREL)
- Energy Storage research, National Laboratory of the Rockies (formerly the National Renewable Energy Laboratory, NREL) Lessons: 25
- Energy Explained, US Energy Information Administration
- Residential Energy Consumption Survey (RECS), US Energy Information Administration
- Electric Power Monthly, average retail price of electricity, US Energy Information Administration Lessons: 21
- How much electricity does an American home use? (FAQ), US Energy Information Administration
- Space heating consumed the most energy of any end use in homes, according to latest data (RECS 2020), US Energy Information Administration Lessons: 2
- Standby Electric Generators, North Dakota State University Extension Lessons: 22
- LED Lighting, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026) Lessons: 23
- Planning a Home Renewable Energy System, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026) Lessons: 22
- Balance-of-System Equipment Required for Renewable Energy Systems, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026) Lessons: 25
- Planning a Microhydropower System, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026) Lessons: 28
- Annual Technology Baseline 2025: Residential Battery Storage, National Laboratory of the Rockies (formerly NREL) Lessons: 25
- Comparative Study of Techno-Economics of Lithium-Ion and Lead-Acid Batteries in Micro-Grids in Sub-Saharan Africa (NREL/TP-7A40-73238), National Renewable Energy Laboratory (now the National Laboratory of the Rockies) Lessons: 25
- British thermal units (Btu), US Energy Information Administration, Energy Explained Lessons: 31
- Space heating and water heating account for nearly two thirds of U.S. home energy use, US Energy Information Administration, Today in Energy Lessons: 33
- Heat Pump Water Heaters, US EPA, ENERGY STAR Lessons: 33
- Estimating Daily Domestic Hot-Water Use in North American Homes, Florida Solar Energy Center (University of Central Florida) Lessons: 33
buildings
- Insulation, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026)
- Air Sealing Your Home, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026)
- Passive Solar Homes, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026)
- Ventilation, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026)
- Fans for Cooling and Principles of Heating and Cooling, US Department of Energy, Energy Saver (archived copy; the page was removed from energy.gov in mid-2026)
- Building America Solution Center, US DOE and Pacific Northwest National Laboratory
- Building Technologies Research and Integration Center, Oak Ridge National Laboratory Lessons: 9
- Enclosure Leakage Test, Building America Solution Center (US DOE and PNNL) Lessons: 9
- Design Temperature Limit Reference Guide, US EPA, ENERGY STAR Residential New Construction Lessons: 30
- Night Vent Cooling, Architecture 2030, 2030 Palette Lessons: 32
water
- WaterSense, US Environmental Protection Agency
- Statistics and Facts (WaterSense), US Environmental Protection Agency
- Private Drinking Water Wells, US Environmental Protection Agency
- Well Water Safety, Centers for Disease Control and Prevention
- Water Use in the United States, US Geological Survey
- Rainwater Harvesting, Texas A&M AgriLife Extension
- The Texas Manual on Rainwater Harvesting, Texas Water Development Board
- Residential End Uses of Water, Version 2, Water Research Foundation Lessons: 14
- Septic Systems (SepticSmart), US Environmental Protection Agency
- Water Q&A: How much water do I use at home each day?, US Geological Survey, Water Science School Lessons: 2
- Ground Water and Drinking Water, US Environmental Protection Agency
- Water Reuse, US Environmental Protection Agency Lessons: 19
- How We Use Water (WaterSense), US Environmental Protection Agency Lessons: 14
- WaterSense Homes technical sheet: Service Water Pressure, US Environmental Protection Agency Lessons: 17
- Private Drinking Water and Public Health, Centers for Disease Control and Prevention Lessons: 15
- Guidelines for Testing Well Water, Centers for Disease Control and Prevention
- Rainwater, Storm Water and Graywater, Colorado Division of Water Resources Lessons: 16
- Rainwater Harvesting Registration, Utah Division of Water Rights Lessons: 16
- Private Drinking Water Wells: The Distribution System (G2152), University of Nebraska-Lincoln Extension Lessons: 17
- Using Gray Water at Home: Guide to Complying with the Type 1 General Permit, Arizona Department of Environmental Quality (copy hosted by University of Arizona Cooperative Extension) Lessons: 19
- Summary of North Carolina's Water Reuse Guideline or Regulation for Onsite Non-Potable Water Reuse, US Environmental Protection Agency, Water Reuse Lessons: 19
- Protect Your Home's Water, US Environmental Protection Agency, Private Drinking Water Wells
- How to Care for Your Septic System, US EPA, SepticSmart Lessons: 40
- Water Efficiency Technology Fact Sheets (including Composting Toilets), US EPA, Septic Systems Lessons: 40
food
- USDA Plant Hardiness Zone Map, USDA Agricultural Research Service
- National Center for Home Food Preservation, University of Georgia, with USDA support Lessons: 39
- Complete Guide to Home Canning, USDA, via National Center for Home Food Preservation Lessons: 39
- Dietary Guidelines for Americans, USDA and US Department of Health and Human Services
- FoodData Central, USDA Agricultural Research Service
- Food and Agriculture Organization of the United Nations, FAO
- Planting the vegetable garden (land-grant cooperative extension), University of Minnesota Extension
- Poultry, including backyard flocks (land-grant cooperative extension), University of Minnesota Extension
- Sprout & Fin, hydroponics and aquaponics tracks, The makers of Hearth & Field Lessons: 38
- Beginner's guide: grow your own vegetable garden, University of Georgia College of Agricultural and Environmental Sciences Lessons: 35
- What would be a good site for a vegetable garden?, Iowa State University Extension and Outreach Lessons: 35
- Watering the vegetable garden, University of Minnesota Extension Lessons: 35
- How soon will a newly planted fruit tree begin to bear fruit?, Iowa State University Extension and Outreach Lessons: 36
- Understanding Chill Hours for Fruit and Nut Trees in South Carolina, Clemson Cooperative Extension, Home and Garden Information Center Lessons: 36
- Raising chickens for eggs, University of Minnesota Extension Lessons: 37
- Successfully Raising a Small Flock of Laying Chickens, Penn State Extension Lessons: 37
- Backyard Chickens, Cornell Cooperative Extension, Washington County Lessons: 37
- Summer Heat and Rabbit Production (UNP-0082), Alabama Cooperative Extension System Lessons: 37
- Storing Winter Storage Vegetables, Iowa State University Extension and Outreach Lessons: 39
- Pop Quiz: What Time Is It?, National Center for Home Food Preservation Lessons: 39
- Cornell Composting, Cornell Waste Management Institute Lessons: 41
- The Compost Heap: Basic Composting in Alaska, University of Alaska Fairbanks Cooperative Extension Service Lessons: 41
- 7 CFR 205.203, Soil fertility and crop nutrient management practice standard (USDA National Organic Program), Legal Information Institute, Cornell Law School (text of the federal regulation) Lessons: 41
safety
- Backyard Poultry, Centers for Disease Control and Prevention Lessons: 37
- Burn Wise, US Environmental Protection Agency
- Indoor Air Quality, US Environmental Protection Agency
- Mold, US Environmental Protection Agency
- Heating safety, National Fire Protection Association Lessons: 31
- Carbon monoxide safety, National Fire Protection Association
- Carbon Monoxide Information Center, US Consumer Product Safety Commission
- What to Know: Generators and CO, US Consumer Product Safety Commission Lessons: 27
- Electrical safety, Occupational Safety and Health Administration
- A Brief Guide to Mold, Moisture and Your Home, US Environmental Protection Agency Lessons: 11
- Heating Fire Safety, US Fire Administration (FEMA) Lessons: 31
- Best Wood-Burning Practices, US EPA, Burn Wise
- Avoiding Tap Water Scalds (Publication 5098), US Consumer Product Safety Commission Lessons: 33
- Dioxins Produced by Backyard Burning (January 2025 snapshot), US EPA Lessons: 42
- The Importance of Sending Consumers' Used Lithium-ion Batteries to Electronic Recyclers or Hazardous Waste Collection Facilities, US EPA Lessons: 42
codes
- Building Energy Codes Program, US Department of Energy
- International Residential Code (IRC), including Appendix AQ, Tiny Houses, International Code Council
- NFPA 70, National Electrical Code (NEC), National Fire Protection Association
- Uniform Plumbing Code (UPC), IAPMO
- Adoptable appendices in the International Residential Code for cob construction and tiny houses, International Code Council, Building Safety Journal Lessons: 7
- Commercial Vehicle Size and Weight Program (federal 102-inch width limit), US Federal Highway Administration Lessons: 7
- Energy Savings Analysis: 2021 IECC for Residential Buildings (PNNL-31440), Pacific Northwest National Laboratory, via the DOE Building Energy Codes Program Lessons: 3
- Minnesota Rules 1303.1600, Footing depth for frost protection, Minnesota Office of the Revisor of Statutes Lessons: 17
- Graywater information handout (laundry-to-landscape under California Plumbing Code Chapter 15), City of Dublin, California, Building and Safety Lessons: 19
climate
- National Solar Radiation Database (NSRDB), National Laboratory of the Rockies (formerly the National Renewable Energy Laboratory, NREL)
- IECC climate zone map (Building America Solution Center), US DOE and Pacific Northwest National Laboratory
- US Climate Normals, NOAA National Centers for Environmental Information
- Guide to Determining Climate Zones by County: Building America and IECC 2021 Updates (PNNL-33270), Pacific Northwest National Laboratory, for the US Department of Energy Lessons: 3
general
- Web Soil Survey, USDA Natural Resources Conservation Service
- Composting at Home, US Environmental Protection Agency
- Reducing Waste: What You Can Do, US Environmental Protection Agency
- FEMA Flood Map Service Center, US Federal Emergency Management Agency Lessons: 4
Climate data
The planning tools and Homestead Lab use one representative city per IECC climate zone. Monthly values are rounded teaching approximations from NOAA 1991–2020 climate normals and NREL solar data. They are good for comparing choices, not for designing a system. Use PVWatts and your local climate normals for real numbers.