Homes consume a lot of energy. In the United States, residential buildings account for around 20% of total energy consumption according to the U.S. Energy Information Administration. With rising energy costs and increasing environmental concerns, building energy efficient homes has become a priority for many homeowners and home builders. An energy efficient home aims to reduce energy consumption through smart design, construction techniques and renewable energy use. Let’s explore what makes a home energy efficient and how green living ties into energy efficiency.
Introduction
An energy efficient home is designed and built to maximize energy performance while maintaining comfort. Energy efficient homes utilize a variety of techniques to reduce energy needs for heating, cooling, lighting and appliances. The goal is to create a comfortable and healthy living environment while minimizing energy waste.
Energy efficiency is a key component of green living. Green homes aim to have a low environmental impact through efficient energy and water use, sustainable building materials and indoor environmental quality. An energy efficient home aligns with green values by reducing fossil fuel consumption, lowering greenhouse gas emissions and shrinking the home’s carbon footprint.
This article provides an overview of techniques and features that make a home energy efficient. We’ll look at energy efficient home design, insulation, air sealing, passive house principles, earth-sheltered architecture and renewable energy sources. With an understanding of these core concepts, you can make informed decisions about building or renovating an energy efficient home.
Energy Efficient House Design
The basic design of an energy efficient home maximizes energy performance. Home design factors such as size, layout, solar orientation and construction methods all influence energy efficiency.
Simple Footprints and Smaller Square Footage
Energy efficient homes tend to have a simple, compact shape with a smaller overall square footage. Complex shapes like L-shaped homes tend to lose more heat and are more challenging to properly insulate. A compact rectangular or square footprint reduces the home’s surface area exposed to outdoor conditions. Smaller square footage also means less space to heat and cool.
Passive Solar Gain
Orienting the house to make the most of passive solar gain can significantly reduce heating costs in colder climates. Proper solar orientation means facing the majority of windows toward the south (northern hemisphere) to allow low winter sun to enter and heat the home naturally. Strategic window placement and overhangs on southern facades prevent overheating from high summer sun.
Sustainable Materials
Using sustainably sourced building materials reduces the home’s carbon footprint. Wood from responsibly managed forests, natural linoleum floors and stone countertops are examples of green materials. Reclaimed and recycled content products also boost the home’s overall sustainability.
Efficient Building Techniques
Advanced framing, raised heel trusses and optimized value engineering are construction techniques that reduce material use and waste. Properly installing insulation, windows, doors and utilities according to energy codes also improves efficiency.
Net Zero House Plans
Net zero home designs balance energy loads to result in zero net energy consumption over the course of a year. This is achieved through minimized heating/cooling needs, energy efficiency measures and renewable energy systems. Net zero home plans represent the gold standard of energy efficient house design.
Insulation and Air Sealing
Insulation and air sealing are two of the most important factors that determine a home’s energy efficiency. Proper insulation levels coupled with meticulous air sealing can reduce heating and cooling costs by up to 20%, according to the U.S. Department of Energy.
Good Insulation for Energy Efficiency
Insulation creates resistance to heat flow and is rated by R-value – the higher the R-value, the better it insulates. Aim for R-13 to R-23 in walls and R-30 to R-60 in attics. Use high density foam board around foundations. Install insulation without gaps, voids or compression for best performance.
Air Sealing for Draft Stopping
Drafts can reduce insulation’s effectiveness so air sealing is crucial. Seal penetrations between floors, corners, electric outlets and wherever airflow can leak through. Use caulk, foam sealant, weatherstripping and other sealing methods make the building envelope airtight.
Renewable Energy Options
On-site renewable energy generation like solar panels or geothermal heat pumps will make the home even more energy efficient. We’ll look more at integrating renewables later in the article.
Passive House Design
Passive House is a rigorous green building standard focused on ultra-low energy use. Passive House principles can be applied to create extremely energy efficient homes.
Basic Concepts of Passive House
Passive House design centers around super insulation, airtight construction, heat recovery ventilation and passive solar gain. Combined, these principles enable heating/cooling energy savings of up to 90% compared to standard building methods.
Five Key Principles of Passive House Design:
- Super insulation – insulation levels are boosted significantly higher than normal building standards for maximum efficiency.
- Airtight envelope – very low air leakage of 0.6 air changes/hour at pressure.
- High performance windows – triple pane windows with insulated frames minimize heat transfer.
- Absence of thermal bridges – insulation is continuous and uninterrupted by structural elements.
- Heat recovery ventilation – recycles heat between outgoing and incoming air streams.
Benefits of Passive House Design
Passive House buildings offer many benefits:
- Extremely low energy costs for heating and cooling
- Enhanced comfort with minimal temperature fluctuations
- Good indoor air quality with constant fresh air circulation
- Reduced construction waste from efficiency measures
- Lower embodied energy from less material use
- Smaller heating/cooling systems lower equipment costs
Though challenging to execute properly, Passive House principles allow for the design of zero energy homes with superb comfort and indoor air quality.
Earth-Sheltered Homes
As the name implies, earth-sheltered homes are built with the premise of using surrounding earth to help regulate interior temperatures. They are sunk into the ground on one or more sides and covered with earth.
Energy-Efficient Features
The large thermal mass of the surrounding earth moderates heat loss/gain, reducing artificial heating and cooling needs. Earth covering also provides natural insulation from temperature extremes. Energy savings can range from 20-80% compared to conventional buildings.
Adequate Ventilation
Earth-sheltering creates very airtight homes, so adequate fresh air ventilation systems are critical. Heat recovery ventilators can temper the incoming outside air. Cooling summer air and warming winter air before distribution.
Indoor Air Quality
Since earth-sheltered homes are tightly sealed, indoor air quality can suffer. Proper ventilation as mentioned above is key. Also, choose zero or low VOC materials and finishes.
Soundproofing
The surrounding earth offers effective soundproofing from outside noise. This cocoon of earth also contains internally generated noise for quiet interiors.
Cost of Construction
Earth-sheltered architecture requires specialized design expertise which can add cost. Excavation and retaining walls around the cut portion of the home also add expense. Overall build cost is often 5-10% more than conventional construction.
Downsides of Earth-Sheltered Homes
On the downside, earth-sheltered homes result in large upfront costs and require more maintenance. Water leakage around penetrations is an issue requiring diligent waterproofing. Also, humidity and mold growth need to be monitored and managed carefully.
Renewable Energy Sources
Incorporating renewable energy sources allows an energy efficient home to produce some or all of its own power on-site. Renewable energy offsets electricity drawn from the utility grid, reducing energy costs and your home’s carbon footprint.
Photovoltaic Panels
Rooftop photovoltaic (PV) solar panel systems are the most common home renewable energy source. PV panels convert sunlight into electricity fed into the home. A grid-tied system stores excess energy in the utility grid to offset nighttime use.
Other Renewable Energy Options
Beyond solar, wind turbines can harness wind energy. Geothermal heat pumps use underground temperatures for heating/cooling. Microhydropower generates electricity from small streams. Biomass systems can burn wood pellets or biofuels.
Integrating one or more renewable energy source will enable a net zero energy home. With robust energy efficiency coupled with on-site power generation, a home can achieve true energy independence.
Conclusion
There are many paths to creating a comfortable energy efficient home. Careful planning of size, layout, orientation and building techniques can help maximize energy performance. Robust insulation, comprehensive air sealing, high performance windows and heat recovery ventilation are key passive house strategies. Earth-sheltered architecture uses the ground’s thermal stability to regulate interior temperatures naturally. On-site renewable energy systems like solar panels help offset grid energy use.
With rising energy costs and climate change concerns, energy efficient homes are becoming the responsible choice. Building green homes with energy independence supports sustainable living and reduces environmental impact. Energy efficiency and renewable energy allow us to maintain modern comforts while stewarding the planet’s resources wisely. By making our dwellings more efficient, we take an important step towards a cleaner energy future.
Energy Efficient Appliances
- Overview of EnergyStar ratings and what makes appliances energy efficient
- Types of energy efficient appliances (refrigerators, dishwashers, clothes washers/dryers, etc.)
- Smart appliances and how they optimize energy use
- Savings on utility bills from upgrading to efficient models
Water Conservation Features
- Low-flow plumbing fixtures (toilets, faucets, showerheads)
- Greywater recycling systems
- Rainwater harvesting systems
- Drought-tolerant landscaping
- Benefits of reducing water consumption
Indoor Environmental Quality
- Use of low/no VOC paints, finishes and materials
- Natural daylighting through windows
- Fresh air ventilation systems
- Air filters and humidity control
- Radon mitigation systems
- Creating healthy indoor air quality
Home Energy Management Systems
- Smart home technology for monitoring energy use
- Programmable and smart thermostats
- Automation systems
- Real-time energy use feedback
- Remote control options
