The best eco-friendly house ideas are the ones that cut the energy and water your home uses every day: sealing air leaks, switching to a heat pump, upgrading the water heater, fixing leaks and installing efficient fixtures, then adding solar. Sealing and insulating alone saves an average of 15% on heating and cooling costs, according to ENERGY STAR.
Below we show where a typical U.S. home’s energy goes, then go through 10 ideas with official numbers on what each one saves, starting with the cheapest and most effective.
Where Your Home’s Energy Goes
Heating is the biggest target. In EIA’s latest Residential Energy Consumption Survey (2020 data), space heating used 34.4 of the 76.8 million Btu an average U.S. household consumed in a year, close to half the total (EIA).
| End use (2020) | Energy per household | Share of energy use |
|---|---|---|
| Space heating | 34.4 million Btu | about 45% |
| Water heating | 14.1 million Btu | about 18% |
| Air conditioning | 7.9 million Btu | about 10% |
| All uses | 76.8 million Btu | 100% |
Sources: EIA RECS 2020, table CE3.1; shares are our own calculation and approximate, because EIA’s end-use figures are averages for households that use each end use.
Energy use and spending are not the same thing. The average household spent $1,884 on energy in 2020, and space heating, at $519, was about 28% of that bill, because much of it is done with cheaper fuels (EIA, table CE3.6). Either way, heating, hot water and cooling are where the biggest savings are.
10 Eco-Friendly House Ideas
1. Seal Air Leaks and Add Insulation
Air sealing and insulation are the cheapest way to make a house use less energy. ENERGY STAR estimates they save an average of 15% on heating and cooling costs and 11% on total energy costs (ENERGY STAR). Sealing and insulating ducts can make a heating and cooling system up to 20% more efficient (ENERGY STAR).
Start with the attic, the basement or crawl space, and gaps around pipes, wiring and recessed lights. A professional energy assessment often includes a blower door test that measures air leaks and an infrared scan that shows missing insulation (DOE).
2. Replace Old Heating With a Heat Pump
A heat pump heats and cools with one machine by moving heat instead of burning fuel. The U.S. Department of Energy says it can cut the electricity used for heating by up to 75% compared with electric resistance heating such as baseboard heaters.
Savings are largest in homes that now use electric resistance, propane or heating oil. Prices range from about $2,000 for a one-room mini-split to $15,000 or more for a whole-house system; see our guide to heat pump cost for prices by type and size.
3. Upgrade to a Heat Pump or Solar Water Heater
Water heating is the second-largest energy use in the average U.S. home. An ENERGY STAR heat pump water heater saves a family of four about $550 a year, or about 3,760 kWh, compared with a standard electric water heater (ENERGY STAR). DOE says these units are often two to three times more efficient than conventional electric and gas water heaters (DOE, 2024).
In sunny climates, a solar water heater is another option. Compare prices and payback in our article on solar water heater cost.
4. Install a Smart Thermostat
An ENERGY STAR certified smart thermostat saves about 8% of heating and cooling bills, or about $50 a year (ENERGY STAR). The savings come from turning the temperature down when nobody is home: DOE says setting it back 7–10°F for 8 hours a day can save as much as 10% a year on heating and cooling (DOE).
5. Upgrade Windows or Add Cellular Shades
Replacing single-pane windows with ENERGY STAR windows lowers household energy bills by an average of up to 13% nationwide (ENERGY STAR). New windows are expensive, though, so look at cheaper fixes first.
Cellular (honeycomb) shades are one of them. In a DOE-funded study, they saved up to 20% of heating energy and up to 15% of total heating and cooling energy compared with no shades (DOE, 2021).
6. Choose LED Lighting, ENERGY STAR Appliances and Induction Cooking
These are the easiest energy efficient home ideas to act on, because you can do them one item at a time as things wear out:
- Lighting: ENERGY STAR bulbs use up to 90% less energy and last at least 15 times longer than standard bulbs, saving about $55 per bulb over its life (ENERGY STAR).
- Laundry: ENERGY STAR clothes washers use about 20% less energy and 30% less water, and heat pump dryers use about 70% less energy than conventional dryers (ENERGY STAR).
- Refrigerator: a fridge more than 15 years old could cost about $95 a year to run (ENERGY STAR).
- Cooking: an induction cooktop transfers about 85% of its energy to the food, compared with about a third for gas (ENERGY STAR). It also removes a source of indoor nitrogen dioxide; EPA lists unvented gas stoves among the main indoor sources of the gas and advises using a range hood vented outdoors (EPA).
7. Install WaterSense Fixtures and Fix Leaks
Each American uses an average of 82 gallons of water a day at home, and the average family spends more than $1,000 a year on water, according to EPA WaterSense. EPA estimates that:
- replacing old toilets with WaterSense models saves 13,000 gallons and $130 a year;
- WaterSense showerheads save more than 2,700 gallons and $70 a year;
- household leaks waste about 9,400 gallons a year per family.
Less hot water also means less energy for the water heater. For why saving water matters even though it is renewable, see is water a renewable resource.
8. Harvest Rainwater for the Garden
One inch of rain on 1,000 sq ft of roof produces about 600 gallons of water (Texas A&M AgriLife data, in the iSWM manual). Rain barrels or a cistern can supply garden irrigation and cut summer water bills.
Rainwater collection rules differ by state. In Colorado, for example, a household may use up to two rain barrels with a combined capacity of 110 gallons (Colorado Division of Water Resources). Check your state and local rules before installing a large system.
For more outdoor ideas, see our sustainable backyard ideas.
9. Add Rooftop Solar Panels
Rooftop solar replaces grid electricity with power from your own roof. The median U.S. residential solar system installed in 2025 was 7.7 kW, according to Lawrence Berkeley National Laboratory. In 2023, state median installed prices ranged from $3.2 to $5.2 per watt before incentives (LBNL Tracking the Sun).
The federal 25D tax credit no longer applies to systems installed after December 31, 2025 (IRS), so payback now depends more on local electricity rates and state programs. Before you get quotes, check the best roof orientation with our solar panel direction tool.
10. Choose a Cool or Green Roof
When the roof needs replacing anyway, the material you choose matters. On a sunny summer afternoon a reflective “cool” roof can stay more than 50°F cooler than a conventional roof, which can reach 150°F or more (DOE). In cold climates the extra winter heating can cancel out the summer savings, so cool roofs make most sense in hot regions.
Green roofs, covered with plants, can have surface temperatures up to 56°F lower than conventional roofs and can reduce stormwater runoff by 60% to 100%, depending on the type (EPA). They need a structure that can carry the extra weight, so they are more common on new builds and flat roofs.
More Sustainable Home Ideas: Materials and Waste
Two ideas from the original version of this article still matter, even though they save little energy:
- Reuse and recycled building materials. The U.S. generated about 600 million tons of construction and demolition debris in 2018, and more than 90% of it came from demolition (EPA). Reclaimed wood, salvaged fixtures and recycled-content materials keep some of that out of landfills.
- Compost food scraps. Food is 24.1% of the municipal waste sent to U.S. landfills, the largest single material, and wasted food is responsible for 58% of landfill methane emissions (EPA). A backyard bin or a city collection program turns it into soil instead. Our list of easy ways to recycle at home covers the rest of the household waste.
Which Eco-Friendly Home Improvements Pay Off First?
| Idea | What it saves | Source |
|---|---|---|
| Air sealing and insulation | 15% of heating and cooling costs | ENERGY STAR |
| Heat pump (vs. resistance heat) | up to 75% of heating electricity | DOE |
| Heat pump water heater | about $550 a year (family of four) | ENERGY STAR |
| Smart thermostat | about 8% of heating and cooling, ~$50 a year | ENERGY STAR |
| ENERGY STAR windows (vs. single-pane) | up to 13% of energy bills | ENERGY STAR |
| WaterSense toilets | 13,000 gallons and $130 a year | EPA |
| WaterSense showerheads | 2,700 gallons and $70 a year | EPA |
Sources: linked in each section above.
How to Make Your Home More Eco-Friendly: Where to Start
Fix the building before you add equipment. Get an energy assessment, seal and insulate, then size a heat pump or solar system for the smaller load that is left. Federal rules point the same way: DOE’s Program Notice 26-2 (May 2026) requires homes using the federal electric home rebates (HEEHR) to complete insulation and air sealing before heating and cooling upgrades, unless the home is already sealed well enough.
The federal 25C and 25D tax credits ended after 2025, so check with your state energy office and utility for current rebates before you buy. Many of the most effective steps, like sealing leaks, setting back the thermostat and fixing a running toilet, cost little or nothing. For more examples of technology that helps, see our list of green technologies you can use at home.
Frequently Asked Questions
What makes a house eco-friendly?
An eco-friendly house uses less energy and water and produces less waste over its life. In practice that means good insulation and air sealing, efficient electric heating and appliances, water-saving fixtures and, where it makes sense, on-site renewable energy such as solar.
What is the cheapest way to make my home more energy efficient?
Air sealing, adding attic insulation, setting back the thermostat and switching to LED bulbs are the lowest-cost steps. ENERGY STAR estimates sealing and insulating alone saves an average of 15% on heating and cooling costs.
Are there still tax credits for green home improvements in 2026?
The federal 25C home improvement credit and the 25D residential clean energy credit do not apply to property or systems installed after December 31, 2025. Some states offer federally funded Home Energy Rebates, and many utilities run their own programs, so check current rules locally.
Is rainwater harvesting legal?
It is legal in most states, but limits vary. Colorado, for example, allows up to two rain barrels totaling 110 gallons per household. Check your state water agency’s rules before installing a system.
What is the most eco-friendly way to heat a house?
For most homes, a well-insulated house heated by an electric heat pump uses the least energy. DOE says heat pumps can cut heating electricity by up to 75% compared with electric resistance heat.
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