Green home design strives to construct a house that saves money and is good for the environment and the occupants of the home. Green or sustainable home building reduces energy, water, and material use during and after construction. Green building also creates a durable house that has a healthy indoor environmental quality (IEQ) and a high level of comfort for its occupants. Ultimately, building a green home increases the resale value of the house. In fact, a report by the University of Texas at Austin and the U.S. Green Building Council (USGBC) concluded that new LEED-certified homes (green) in the Austin-Round Rock Metropolitan Statistical Area are valued an average of $25,000 more than conventional homes. In addition, according to new research published in the Green Multifamily and Single Family Homes 2017 SmartMarket Brief, green home construction is growing among both single-family and multifamily home builders. The study found that at least one-third of the single-family and multi-family builders surveyed said that green building is a major portion of their overall activity. By 2022, this number is predicted to increase to nearly one-half in both the single-family and multi-family sectors.
National Association of Home Builders (NAHB) Chairman Granger MacDonald, a home builder and developer from Kerrville, Texas states, “Building green is no longer a niche business; our members recognize the value of building green and are incorporating these elements into their standard business practices.”
There are numerous elements to consider when building a green home. A green home design considers energy, water, and waste efficiency along with IEQ factors such as indoor air quality (IAQ), thermal, light, acoustic, privacy, security, and the function of the space. Green building construction is also resilient and low maintenance. The goals of green home design are to achieve net-zero energy use3 and create a durable, comfortable, healthy, low maintenance home with high IEQ.
10 Considerations for Building a Green Home
1. A Whole-Building System Approach for Designing a Green Home
The whole-building system approach treats a house as a single energy system in which each part impacts the efficiency of the entire home. The whole-building system approach efficiently uses electricity, water, and other natural resources and strives to reduce material consumption and waste. Also, it ensures that all the building professionals are informed and understand every aspect of the design that impacts energy use in the house. The goal of the whole-building system approach is to create a home with a healthy and safe indoor environment, lower utility and maintenance costs, and improved durability and comfort. Homeowners, architects, and contractors concur that designing a green home needs a whole-building system approach.
2. A Green Home has a High Performance Building Envelope
A high performance building envelope minimizes heat, air and moisture infiltration and is crucial to creating a green home. Essential design components of a high performance building envelope are continuous insulation (CI)4 and application of an air and moisture barrier. Continuous insulation prevents gaps of insulation where heat can enter or escape (thermal bridging), and a high performance air and moisture barrier stops air leakage which degrades energy performance of a building. Moisture resistance is key to preventing rot and the growth of mold and mildew, which can tremendously degrade the integrity and IEQ of a home. A high performance building envelope should also include energy efficient windows, skylights, and doors appropriate to the home’s climate zone. Essential to green home design is a high performance building envelope that minimizes heat, air and moisture infiltration within a home.
3. Cool Roofs of a Green Home
A cool roof keeps the home and attic spaces cool by shielding against solar heat gain. Materials for a cool roof include high thermal mass materials5 like clay, tiles, or slate that are reflective or have light colored pigments that cast back the sunlight. Cool roofs reduce energy bills and improve indoor comfort. Cool roofs can also extend the roof’s service life.
4. The Heating, Cooling and Ventilation Systems of a Green Home
Because a home’s heating and cooling system account for 48 percent of a home’s energy use, the design of a green home should consider high-efficiency heating and cooling systems that use less energy. The most efficient HVAC system is 95 percent efficient; meaning 5 percent of the energy produced is lost. Controlling ventilation of a green home is also critical because the air-tightness of a green home can trap pollutants (like radon, formaldehyde, and volatile organic compounds). Methods of ventilation may include an energy recovery ventilation system and spot ventilation, such as exhaust fans in the bathroom and kitchen, along with natural ventilation.
5. Renewable Energy Sources of an Energy-Efficient Home
The design of a stainable home should strive to generate as much energy as it uses by installing renewable energy measures: for example, microhydropower, solar photovoltaic (PV) panels, wind system, and small "hybrid" electric system. Renewable energy sources can lessen or even eliminate a home’s utility bills and may even have tax incentives.
6. Energy-Efficient Appliances, Electronics, Water Heater, Lighting, and Smart Devices of a Green Home
Design of a green home should include ENERGY STAR appliances, energy-efficient water heaters, ENERGY STAR®-labeled office equipment and electronics, and energy-efficient lighting like light-emitting diodes (LEDs), compact fluorescent lamps (CFLs), and halogen incandescent. Smart home devices like programmable thermostats, occupancy or motion sensors, CO2 and other air quality alarms, can also save money and energy, along with making a home safer.
7. Insulated Slab Foundation of an Energy-Efficient Home
In many slab-on-grade foundation designs, significant areas of the slab edge is uninsulated and remains exposed to the outdoor environment, allowing heat energy to travel into and out of the home. This can significantly impact the energy efficiency of the building and lead to uncomfortable indoor conditions. To avoid this condition, the exposed portions of the slab should be insulated. Additional precautions must also be taken in areas where termites are present as the foam insulation can provide an entry point into the home.These small details taken together all contribute to a greener and more comfortable home design.
8. Site Orientation of a Green-Sustainable Home
Correct site orientation (passive solar design) of a green home is crucial for taking advantage of the sun’s energy. For instance, the north-south orientation minimizes direct sunlight during the summer (which reduces cooling demands) while maximizing sunlight during the winter (which reduces heating demands).
9. A Green Home is Durable
A sustainable home design utilizes durable products and materials. Durable products are sustainable because they last longer, so the raw materials, energy, and environmental impacts invested in them are spread out over more time. Durability also improves the resilience of a home against natural disasters like hurricanes, tornadoes, and fires. Again, saving energy and money to rebuild and repair.
10. Bautex Blocks are the Ideal Choice for a Green Home Design: Energy-Efficient, Durable, Comfortable, Healthy and a High IEQ
A green home is a sustainable house that is sensitive to human impact on natural ecosystems. The ultimate goal of green home design is to achieve net-zero energy use and create a durable, comfortable, healthy home with high IEQ. Visit Bautex Systems for more considerations for building a green home.
1Green homes are good for the environment because they battle against increasing greenhouse gases and global warming. Negative impacts of global warming include rising sea levels due to growing rates of glacial melting, more acidic oceans, due to climbing carbon dioxide levels, and more frequent and severe weather events.
2Sustainable design aims to reduce depletion of critical resources like water, land, raw materials and energy. Sustainable design of also prevents the destruction of the ecosystem.
3A net-zero energy home makes as much energy as it uses.
4 Continuous insulation is required by the ASHRAE 90.1 and the International Energy Conservation Code (2015 IECC). Continuous insulation is defined by the ASHRAE Standard 90.1-2013 as insulation that is uncompressed and continuous across all structural members without thermal bridges other than fasteners and service openings. A thermal bridge is a section of a wall assembly that allows heat and energy to flow through it at a higher rate than the surrounding area and reduces the effective R-value of the wall assembly.
5High thermal mass materials can absorb and store heat energy. High thermal mass materials help stabilize temperature shifts within a home by slowing the rate of heat transfer. Water, stone, brick, and concrete are examples of materials with high thermal mass. Steel, wood, and carpeting have low thermal mass and not good materials for green home design.
6Volatile organic compounds (VOC) are chemicals used to manufacture and maintain building materials, interior furnishing, cleaning products and personal care products. Emissions of VOCs from these products can cause nose, eye and throat irritations, headaches, nausea and damage to the kidney, liver and central nervous system. Some organics can even cause cancer in animals and humans.