How Do I Build An Energy-Efficient Home?
Energy efficiency refers to reducing the amount of energy required to provide products and services. An energy-efficient home uses less energy to provide the same, or higher, level of comfort compared to a standard house. There are several reasons why building an energy-efficient home is important:
It reduces energy bills. An energy-efficient home can save 30% or more on heating and cooling costs compared to a typical home. This puts money back in the homeowner’s pocket.
It increases home comfort. Proper insulation, air sealing, efficient systems, and quality windows keep temperatures comfortable in an energy-efficient home.
It lowers environmental impact. Using less energy means generating less pollution from power plants and extracting fewer natural resources.
It improves durability. Energy-efficient construction often involves high-performance materials and systems that can last longer.
It provides health benefits. Energy-efficient homes have better indoor air quality and temperature control, leading to better comfort and health.
It raises property value. Home buyers are increasingly seeking energy-efficient homes. Efficiency features can directly increase resale value.
Building an energy-efficient home makes sense from environmental, health, comfort, durability, and financial perspectives. The rest of this article will explore key steps for how to build an energy-efficient house.
Site Selection
Site selection is a crucial first step when building an energy efficient home. Choosing the right location and orientation can help maximize natural lighting and shading to reduce energy usage. As the Zero Energy Project explains, the site should be free of obstructions that could block sunlight, like neighboring buildings or trees (https://zeroenergyproject.com/2014/09/03/2237-2/). Orienting the home to face south or southwest allows for optimal solar gain in the winter and shading in the summer. An east-west orientation works as well for allowing low morning and afternoon sun in the winter. Dale Dickkut further emphasizes assessing seasonal sun patterns when selecting a site for an energy efficient home (https://www.linkedin.com/pulse/site-selection-energy-efficiency-dale-dickkut). Overall, choosing a site with good access to natural light and shading from trees or overhangs will enable an energy efficient design.
Insulation
Proper insulation is crucial for making a home energy efficient. Insulation works by slowing heat flow and reducing energy waste. The most common types of insulation include:
Fiberglass – Made from extremely fine fibers of glass, fiberglass insulation comes in both batt and loose forms. It is an affordable option that provides effective insulation against heat transfer and air infiltration. However, fiberglass can be irritating to skin and does not block moisture (The Importance of Insulation for Energy Efficiency at Home).
Spray foam – Applied as a liquid, this expands to fill cracks and crevices while hardening into a solid foam. It offers excellent thermal performance and air sealing. Spray foam insulation can be used in walls, attics, crawl spaces, and on exposed pipes or ducts (Choosing the Best Insulation for Energy Efficiency).
Cellulose – Made from recycled paper products, cellulose insulation is applied as loose fill or wet sprayed. It is effective at reducing heat transfer and air infiltration while being environmentally sustainable. Cellulose settles over time so it requires an attic depth of at least 10-12 inches (Top Rated Insulation Contractor – Danbury, Connecticut).
Windows
When updating or replacing windows in your home, choosing energy efficient windows can help reduce your energy costs and improve comfort. According to the U.S. Department of Energy, heat gain and loss through windows accounts for 25-30% of residential heating and cooling energy use (Source: Energy.gov). Energy efficient windows have special coatings and glazing that improve their insulation properties.
The glazing refers to the glass panels in the window unit. Multiple panes of glass with air spaces between create additional insulation. Energy efficient glazing options include double pane, triple pane, low-emissivity coatings, inert gas fills, and warm-edge spacer systems (Source: Energy.gov). When shopping for new windows, look at the National Fenestration Rating Council (NFRC) ratings to compare energy performance between different products.
Key factors to consider for energy efficient windows are the frame material, the number of panes or layers of glass, the types of coatings and glazing, gas fills, and proper installation. Upgrading to energy efficient windows can help reduce heating and cooling costs, improve home comfort, and provide other benefits like noise reduction and UV protection (Source: Pella).
Heating and Cooling
The most efficient heating and cooling options for new home construction utilize renewable energy like geothermal and solar power. According to the US Department of Energy, geothermal heat pumps can reduce energy consumption for heating by 44%-72% compared to traditional heating and cooling systems (https://www.energy.gov/energysaver/heating-and-cooling).
Geothermal systems use underground heat to provide heating and cooling. During winter, the earth’s warmth is transferred indoors through underground pipes. In summer, the relatively cooler temperature of the earth absorbs heat from the air to provide cooling. Though installation costs are higher, geothermal systems have lower operating costs compared to conventional systems.
Solar energy can also be harnessed to reduce heating and cooling costs. Solar thermal collectors absorb heat from the sun to warm air or water, which is then used directly or stored for later heating needs. Solar PV panels convert sunlight into electricity to power heat pumps, fans or other systems. Combining solar power with geothermal further increases efficiency.
For conventional HVAC systems, look for ENERGY STAR certified equipment which meets strict energy performance criteria set by the EPA. Proper sizing of HVAC equipment based on home size and climate is also key for optimal efficiency.
Appliances
When selecting appliances for an energy-efficient home, look for the EnergyStar label (The most energy efficient appliances in 2022). EnergyStar certified appliances meet strict energy efficiency guidelines set by the EPA and Department of Energy, so they use less energy and can help lower your utility bills.
Focus on choosing EnergyStar models for the major appliances like refrigerators, dishwashers, washing machines, and dryers. According to EnergyStar, certified appliances are 10-50% more energy efficient on average than conventional models. For example, an EnergyStar refrigerator uses about 40% less energy than conventional models (Select Energy Efficient Appliances & Electronics Step 11).
Other appliances to look for EnergyStar models include air purifiers, air conditioners, furnaces, water heaters, and ceiling fans. Choosing efficient appliances can have a significant impact in reducing home energy costs over time.
Lighting
Making use of natural lighting during the day is one of the easiest ways to reduce energy consumption from artificial lighting (source). Position windows and skylights to maximize sunlight exposure in rooms where people spend the most time. Utilize light shelves and reflective surfaces to bounce natural light deeper into rooms.
When artificial lighting is needed, LED bulbs are the most energy efficient option (source). LED bulbs use at least 75% less energy and last up to 25 times longer than traditional incandescent lighting. Replace all light fixtures and bulbs with Energy Star certified LED lighting. Consider installing dimmers, motion sensors, and timers on lights to further reduce electricity use.
Water Efficiency
One of the key ways to build a more efficient home is to utilize water-saving fixtures and appliances. According to the EPA, the average American family uses over 300 gallons of water per day at home, with toilets, clothes washers, showers, and faucets accounting for the bulk of household water use (Residential End Uses of Water, Version 2: Executive Report). Installing low-flow toilets, showerheads, and faucet aerators can significantly cut down on unnecessary water waste.
Low-flow toilets use 1.28 gallons per flush compared to old models which used 3.5 gallons per flush. Low-flow showerheads restrict water flow to 2.5 gallons per minute yet provide equal water pressure. And adding aerators to faucets and kitchen sinks restricts flow while maintaining useful pressure. Together, these simple upgrades can reduce household water use by 30% or more.
Greywater systems take things a step further by recycling water from sinks, showers, washing machines, etc to irrigation and other non-potable uses. Though requiring more complex plumbing, greywater systems can reduce household water needs by up to 50%, resulting in significant cost savings and environmental benefits (Water efficiency starts in our homes).
Renewable Energy
Adding renewable energy sources such as solar panels and wind turbines to your home can significantly reduce your energy bills and decrease your carbon footprint. According to the National Renewable Energy Laboratory (NREL), renewable energy accounted for about 11% of total U.S. energy consumption and about 17% of electricity generation in 2017 (https://www.nrel.gov/analysis/re-futures.html). With the right conditions, renewable energy systems can provide up to 100% of a home’s electricity needs.
Solar panels are one of the most popular renewable energy options for homes today. The average home system is between 3-8 kilowatts and costs $15,000-$25,000 installed. The payback period is typically between 5-8 years but can be accelerated by federal and local incentives. According to the Solar Energy Industries Association (SEIA), there is enough solar energy that falls on the United States in just one hour to provide power for the entire country for a full year (https://www.seia.org/initiatives/whats-megawatt). With smart positioning and no shading, solar panels can offset 50-75%+ of your home’s electricity usage.
Small wind turbines are another option, either stand-alone or combined with solar panels. Residential wind turbines range from 400 Watts to 100 kW but most homes use 1.8 to 10 kW turbines. The cost is around $3,000-$35,000 installed depending on your property size, local wind speeds, zoning laws, and incentives. With the right conditions, small wind turbines can offset 20-90% of your electricity usage. The U.S. Department of Energy found there is enough onshore wind capacity to power the entire country more than 10 times over (https://www.energy.gov/eere/wind/advantages-and-challenges-wind-energy).
Certifications
There are several certifications available that designate a home as energy efficient. Obtaining these certifications indicates the home meets stringent efficiency standards and can help with resale value and financing.
LEED
Leadership in Energy and Environmental Design (LEED) is a green building certification program through the U.S. Green Building Council. LEED homes must meet requirements in areas like energy efficiency, materials, water use, and indoor environmental quality. There are four LEED certification levels: Certified, Silver, Gold, and Platinum.1
ENERGY STAR
ENERGY STAR certification is administered by the EPA and Department of Energy. An ENERGY STAR certified home is at least 15% more energy efficient than homes built to code. Requirements focus on effective insulation, high-performance windows, tight construction, efficient heating/cooling systems, and third-party verification.2
Passive House
The Passive House Institute US (PHIUS) administers the Passive House standard for ultra-low energy buildings. Passive House certification requires stringent standards for airtight construction, super insulation, elimination of thermal bridges, and energy recovery ventilation. Passive House homes use up to 90% less heating and cooling energy.1
