The Core Elements of Sustainable Home Building Design

We organize our approach around four core, interconnected areas that should be considered in designing, building, and operating sustainable homes: Resource Conservation, Energy Conservation, Water Conservation, and Environmental Quality.  Many of the products, technologies and building techniques that we have selected address multiple areas within this list.

• Resource Conservation – Resource conservation focuses on reducing the demand that home construction and operation have on resources in general and, in particular, on non-renewable resources that are used to build and operate the home.  This means reducing both the amount of resources used and the waste generated by manufacturing the materials used to build and outfit the home, by the construction process, and finally by living in and operating the home.  Specific areas of focus include:
  • Efficient Design – Design efficiency means creating homes that are right sized for the resident’s needs and that are efficiently designed to minimize the amount of materials, such as wood and concrete, needed to build the home.
  • Use of Resilient or Durable Materials, Durable Design, Durable Construction Techniques – A durable home lasts longer, requires less maintenance, uses less materials over the life of the home, and generates less solid waste by reducing the need for replacing and repairing worn or failing components.
  • Use of Materials and Material Manufacturers who employ the 3 R’s: Reduce, Reuse, Recycle – Green building can reduce the resource load of the house on the environment by selecting materials and products for the home that come from manufacturers who utilize the 3 R’s.  They have reduced their consumption of resources by reducing the amount of materials incorporated in their products, reusing materials, and/or incorporating recycled materials and other waste streams as inputs into the production of their products.
  • Use of products from renewable resources – The selection of materials and products that utilize renewable and rapidly renewable resources, such as wood from sustainably managed forests or rapidly renewable resources such as bamboo.  These materials generally do not contribute to the depletion of our natural resource pool.
  • Use of locally or regionally sourced resources and materials – The use of materials and products that are produced within 500 miles of the site reduces the energy requirements for transportation and helps support local businesses and the local economy.
  • Waste reduction and recycling – Reuse and recycling of waste materials generated from the construction of the home and from the operation of the home lowers the solid waste burden on landfills and provide a source of materials for use in new green products.

• Energy Conservation – Energy conservation focuses on reducing the energy consumed by the home and its inhabitants as well as substituting clean and renewable energy sources for traditional ‘dirty’ energy sources.  There are several concomitant benefits that include a smaller carbon footprint for the home and its inhabitants, less air and water pollution generated by the home, and the improved comfort and health of its inhabitants.  The elements of energy conservation are generally applied in the following order:
  • Passive Design Techniques – Passive solar design elements take advantage of sun and shade to heat and/or cool the home and include building orientation, window and eave design and placement, landscape design, and the use of thermal masses to store and radiate heat.
  • Thermal Efficiency – Thermal efficiency starts with the shell of the home and includes the selection of improved traditional or advanced framing systems, insulated foundations, advanced insulation systems, along with thermally efficient windows, doors, skylights, and roofing systems.  It also includes good, quality building techniques and materials such as adequate caulking, moisture control systems, etc.  These elements are cost effective and can reduce heating and air conditioning loads by 40-60% over traditionally-built homes.
  • Energy Efficient Elements – Use of high efficiency lighting, appliances, and other electrical systems to reduce electrical loads of the home, energy efficient water heating systems and The use of management systems such as home automation and automated lighting systems can optimize the use of energy by lighting systems, home heating and cooling systems, and other appliances and energy-consuming elements in the home.
  • Alternative Energy Sources – The integration and use of clean, renewable energy sources available on the site including geothermal heating and air conditioning (ground source heat pumps), solar thermal (hot water) and photovoltaic (solar electric) systems, and small scale wind generators.

• Water Conservation – Water conservation includes reducing the amount of water consumed by the home and its inhabitants.   It also includes reducing the homes impact on the local watershed and aquifer.
  • Efficient Water Use – Low flow fixtures, water efficient appliances, efficient irrigation systems, and gray water systems all aim to reduce the overall consumption of water.
  • Water capture/reuse – Rain harvesting systems that capture rainfall for reuse in irrigation reduce storm water runoff and increase water infiltration.  Gray water systems similarly capture useable wastewater for irrigation.
  • Water Quality management – High-efficiency water purification systems for potable water and use of a variety of techniques, from high-efficiency septic systems to landscaping elements, can be used to clean water infiltrating into the aquifer and water discharging to the watershed.
  • Storm water management – Managing the storm water runoff from the home means improving both its quality and the timing of its release into the watershed to more closely match the characteristics of the natural runoff cycle.  Landscaping elements such as rain gardens, permeable surfaces, rainwater infiltration systems, and other approaches turn water that would normally become surface runoff into a resource that waters trees, recharges groundwater, and provides a longer-term water source for streams. These approaches function to improve water quality by removing some pollutants from the runoff as it infiltrates the ground.

• Environmental Quality – This broad catchall for a variety of micro- and macro-environmental goals focuses on reducing or eliminating the impact of housing and house building on the natural and human environment.  These include:
  • Indoor environmental quality – Improvements in the environmental quality of life for people living in green homes may arise from improved indoor air quality, improved ventilation, etc.  Approaches include the use of low VOC materials in home construction and finishing, solar/natural lighting systems, automated ventilation control systems, etc.
  • Pollution Prevention/Reduction – The goal here is to limit the pollution that the home and its inhabitants create either directly from the operation of the home (e.g., energy use) or indirectly from the production of the products used in home construction.
  • Habitat Protection/Development – Backyard habitat programs, the use of native plantings in landscaping, and other mitigating efforts can not only limit the impact a home has on the natural environment but can even improve local conditions.
  • Soil and Water Conservation – The impact of the construction and operation of the home on soils and watersheds can be reduced or eliminated by limiting erosion, improving rainwater infiltration, and cleaning all runoff from the home site before it is discharged into the watershed.