• Overview
• Energy-Efficient Features at a Glance
• Understanding Energy Consumption
• Steps any homeowner can take to save energy
• Tight Construction
• Heating
• Cooling
• Electrical Power
• Sustainable Materials
• Water Conservation and Landscaping <--
• Performance
• FAQ
• Artistic Aspects
• Principal Participants
• Links and Resources
• Webmaster Publications
• Floor Plans
• Awards & Recognition
• Original Website-- Building an energy efficient house

Toilets have long been the greatest water user in the house, accounting for more than one-quarter of the total daily indoor water use in a typical single-family home. Older, conventional toilets (those made prior to 1992 when new federal plumbing standards were implemented) use between 3.5 and 8 gallons per flush (gpf). Federal law now mandates that all toilets manufactured in the U.S. must operate on 1.6 gpf or less. Replacing an old 3.5 gpf toilet with an ultra-low-flush (ULF) 1.6 gpf toilet can result in substantial water savings--roughly 10 gallons/person/day.

(To determine the flush volume of an older toilet, look for the date of manufacture on the underside of the tank lid or on the back inside wall of the tank. Toilets made from the early 1980s to 1992 use 3.5 gallons/flush. Those made earlier use from 5 to 8 gallons/flush. Newer ULF toilets should have a mark near the seat hinge indicating that they use 1.6 gallons/flush.)

The even lower-flow, dual-flush toilet takes water efficiency another step further. Instead of just one flushing option, dual-flush toilets allow the user to select either a full 1.6-gallon flush or a "liquid only," 0.8-gallon flush. Long popular in Europe and mandated in Australia and Singapore, the dual-flush toilet is becoming easier to find in this country as well. When Caroma dual-flush toilets were selected for this house just a few years ago, the Australian company dominated the market; now most other major toilet manufacturers offer dual-flush models as well.

The increased availability of, and demand for, High-Efficiency Toilets (HETs) such as these reflects a growing recognition of the compelling need to conserve valuable water resources. An HET is defined as a fixture that is at least 20 percent more efficient than the current 1.6 gpf standard--in other words, a toilet that has an average maximum flush volume of 1.28 gpf. (In the case of dual flush toilets, a full flush must be no more than 1.6 gpf and a reduced flush no more than 1.1 gpf.) A number of water utilities and municipalities have incorporated this new standard in their toilet replacement programs, offering financial incentives (rebates and vouchers) to install HETs. And the U.S. Green Building Council's Leadership in Energy and Environmental Design (LEED) rating system awards extra points for high-efficiency plumbing fixtures.

Consumers will soon have help in identifying the most water-efficient toilets on the market. The EPA has developed a new labeling program that will recognize products and programs that meet EPA criteria for water-efficiency and performance. High-efficiency toilets will be the first product to display the EPA's new WaterSense label. When it begins appearing on HETs in 2007, the label will signal that the fixture has been independently certified by a third party to confirm that it meets EPA criteria for efficiency and performance.

Showerheads and faucets present additional opportunities for water conservation. To meet current federal plumbing standards, showerheads manufactured in the U.S. must restrict water flow to 2.5 gallons per minute (gpm) or less. By replacing older (pre-1992) 4.5-gpm showerheads with new low-flow fixtures, a family of four can save approximately 20,000 gallons of water per year.

As for faucets, federal guidelines mandate that they use no more than 2.2 gpm. Replacing older 3-to-7-gpm faucets with more efficient fixtures--or installing low-flow aerators in existing faucets--can achieve significant water savings. And by reducing the demand on the home's water heater, both the low-flow showerheads and the more efficient faucets will result in energy savings as well.

Looking to the future, the EPA is finalizing a certification program for high-efficiency bathroom sink faucets and faucet accessories (e.g., faucet aerators). WaterSense-labeled bathroom sink faucets will use no more than 1.5 gpm.

Water-efficient washing machines and dishwashers can save thousands of gallons of water annually compared to more conventional models.

As of January 2007, ENERGY STAR-qualifed clothes washers must meet stricter efficiency standards for both water and energy consumption. To meet the water-efficiency standard, a machine must have a Water Factor of 8.0 or less. The Water Factor (WF) is a measure of the amount of water needed to wash one cubic foot of laundry. (ENERGY STAR had not included a Water Factor requirement in its standards previously.) Qualified clothes washers must also have a minimum Modified Energy Factor (MEF) of 1.72 (compared to the previous 1.42 standard), a measure of the energy consumption of the entre laundry cycle (washing and drying).

A water-efficiency standard has not yet been established for dishwashers, but since most of the energy used by dishwashers is the energy required to heat the water they consume, an energy-efficient dishwasher is also one that uses less water to do the job. In fact, ENERGY STAR-qualified dishwashers typically use 40 percent less water than non-qualified models. To earn the ENERGY STAR label, dishwashers must have a minimum Energy Factor of 0.65.

Leaks account for about 13 percent of the water used in a typical home. A slowly dripping faucet or a toilet that keeps "running" can waste thousands of gallons of water a year. To check for leaks, read the water meter before and after a two-hour period in which no water is being used. After the test period, if the meter has a higher reading, there is probably a leak.

A few small changes in every day habits can also result in significant water savings. Turning off the tap while brushing your teeth can save well over 1000 gallons/person/year. A five-minute shower (12.5 gallons of water with a new showerhead) instead of a bath will save 20-30 gallons each time. Look for more water saving tips from online resources such as Water: Use It Wisely.

Outdoor Water Management
In undeveloped natural areas, there is very little stormwater runoff. As an area is developed, however, vegetation is removed and replaced with impervious surfaces (roads, rooftops, sidewalks, and parking areas), which prevent rainwater from soaking into the ground and replenishing groundwater. The resulting runoff picks up pollutants (oil, grease, lawn chemicals, bacteria, sediment), flows into the storm sewer system, and then is discharged directly into the nearest stream, river or lake. Impervious surfaces increase the volume and rate of stormwater runoff and contribute to flooding, erosion, habitat degradation, and water quality impairment.

Older urbanized areas face another problem in managing stormwater. Cities like Chicago and Evanston have combined sewer systems in which stormwater and sanitary wastes are collected in the same pipe and conveyed to a treatment plant. Here the rainwater gets treated to the same degree and at the same cost as raw sewage. During heavy rainfall, when the flow exceeds the treatment and storage capacity of the system, the combined waste stream is allowed to flow into a nearby body of water (e.g., Lake Michigan).

Green solutions to stormwater management make use of rainwater where it falls, treating it as an asset rather than a waste product. One effective green solution is to pave driveways and parking areas with permeable paving, which allows rainwater to seep into the ground, thus recharging groundwater and reducing stormwater runoff.

At this house, two types of permeable pavers were installed. Ecoloc pavers were used in front of the house, providing a highly durable and attractive surface for driving and parking. These interlocking concrete paving blocks are separated by holes that are filled with gravel and allow the rainwater to flow through to a bed of crushed stone below. Turfstone "lattice" pavers, with openings that allow grass to grow through, were used along the side of the house, leading to the garage. These grassy pavers provide additional parking while creating a cooling "lawn effect."

Rainwater harvesting--collecting and storing rainwater for future use on site--is another green alternative to sending this valuable resource into the sewer system. Harvested rainwater is typically used for landscape irrigation but, with proper treatment, can also be used indoors for flushing toilets, washing clothes and even for drinking. Benefits include lower water bills, reduced demand on the municipal water supply, increased groundwater recharge, and more efficient and appropriate use of precious drinking water.

At this house, most of the downspouts have been connected to a 1000-gallon underground cistern in the southeast corner of the property. A small pump allows the rain water collected in the cistern to be used for watering the garden. Overflow from the cistern flows into the lake.

Landscaping
The landscaping for this house was designed to require less maintenance and use less water than a traditional garden. The amount of conventional lawn area is minimized in favor of drought-tolerant ornamental grasses and wildflowers, hardy perennials, groundcover, trees and bushes. A low berm was built up along the south property line, raising the groundlevel where rainwater used to pool after heavy storms. Plantings on the berm screen the house during the warmer months. A fast-growing evergreen bamboo hedge was planted on the north property line to provide additional privacy.

Links and Resources

• WaterSense is a new EPA-sponsored initiative to promote water efficiency and conservation. The WaterSense label will help consumers identify products and programs that meet water-efficiency and performance criteria. A list of toilets that qualify for the WaterSense label will be available in 2007; a certification program for irrigation professionals will also come online in 2007.

• The Rocky Mountain Institute outlines a variety of strategies to improve household water efficiency.

• The California Urban Water Conservation Council's Water Saver Home (H₂OUSE) provides many helpful tips on saving water in all parts of the house.

• Water--Use It Wisely, a national conservation campaign, offers numerous tips for saving water inside and outside the home.

• Water: Demand & Supply, a special report in the Winter 2007 issue of Chicago Wilderness Magazine, examines water issues in the Chicago region.

• The Chicago-based Center for Neighborhood Technology's Green Infrastructure Project promotes green solutions to stormwater management and greater investment in open space.

• Troubled Waters: Meeting Future Water Needs of Illinois, a 2006 report prepared by the Campaign for Sensible Growth, Metropolitan Planning Council and Openlands Project, details critical factors affecting water supplies in the state and makes recommendations for the future.

• An EPA presentation entitled Sustainable Landscaping discusses the environmental impacts of traditional landscaping and the benefits of natural landscaping.