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Thank you for your interest in making the existing housing stock better. This resource is free and open-source for use with residential buildings, with a fee for consultation and certification.
Keep up-to-date with the latest workbook here, which can be used in Google Sheets or Excel for design evaluations.
If you are a GreenHome Institute Inspector or just want something to use to evaluate a home onsite for the basic level of GreenStar use our inspection form here.
You can sort it by your project type and/or goals. In order to find what you are looking for, try using “control F” for keywords or clicking the links in the latest checklists on the credits which bookmark directly to each reference detail in the manual.
Watch our 3 part “how to achieve GreenStar Homes” webinar CE series to learn more
Water leak detection and real-time metering
Platinum
Similar to energy monitoring, water must be monitored in real time to determine water usage, waste, and savings opportunities. The water metering system must be able to detect water leaks and may be able to turn the water off automatically or inform the occupant of the leak.
Verification
Photos of the device installed and details of the device. Manual and training should include details on how to operate and track water use as well as what to do in case of a leak.
Tap water filtration added that is appropriate to the area
Gold | Platinum
Water quality is of great concern in regards to human health. Perform water quality testing and address any concerns. All drinking water must be filtered through reverse osmosis or other effective filtration system.
Alternative approach
N/A
Resources & Studies
GreenHome Institute webinar: Introduction to Air and Water Purification
Verification
Results of water tests. Photos and specifications of the installed filtration system. Details in the instructions to tenant or homeowner on how to maintain and operate the system
Advanced plumbing or hot water test passed
Platinum
Following the DOE Zero Energy Ready Home Requirements Rev 7 page 7 “No more than 0.6 gallons (2.3 liters) of water shall be collected from the hot water fixture before hot water is delivered. Only the fixture with the greatest stored volume between the fixture and the hot water source (or recirculation loop) needs to be tested. To field verify that the system meets the 0.6 gallon (2.3 liter) limit, verifiers shall first initiate operation of on-demand recirculation systems, if present, and let such systems run for at least 40 seconds….Next, a bucket or flow measuring bag (pre-marked for 0.6 gallons) shall be placed under the hot water fixture. The hot water shall be turned on completely and a digital temperature sensor used to record the initial temperature of the water flow. Once the water reaches the pre-marked line at 0.6 gallons (approximately 24 seconds for a lavatory faucet), the water shall be turned off and the ending temperature of the water flow (not the collection bucket) shall be recorded. The temperature of the water flow must increase by ≥ 10 °F.”
Resources & Studies
Review the GreenHome Institute CE webinar: Practically Perfect Plumbing Part 1 and Part 2
Verification
Complete and document the hot water test as listed above
Well water systems must use on-demand softeners
Gold | Platinum
Water softeners, when present, shall run on demand based on water use. Make sure hardness is set to the appropriate level based on water testing. This is not needed for city water systems.
Verification
Photo of the installed system
Drains under tank water heater in or above living space
Certified
Tank water heaters that are above living space or located in it, including a basement with any finished space, must have a drain pan that is piped to a drain. This is to protect against water damage if a leak springs.
An alternative approach
Utility rooms with sloped ground towards the drain will work in place of a pan.
Products that help
Rheem water heaters can come with drain pan and leak detection.
Verification
Photo(s)
Use steel-braided hoses or drain pans under clothes washers
Certified
Steel-braided hoses reduce leaks from clothes washers by 90 percent. A drain pan placed directly under or floor drain located near the washer will prevent further damage to the floor below if a leak occurs.
Alternative approach
Install a water leak monitoring device that restricts flow automatically.
Verification
Photo(s)
Plumbing leak and pressure test shows no leaks
Certified
Every home or building must be tested to ensure there are no water leaks and to measure the water pressure. The test can be done by taking a pressure reading inside or out, turning off the water at the mainline, and then waiting to see if there is a significant pressure drop. Ideally, the test is performed by a plumber using the line depressurization test. If there is a leak, it must be fixed.
Alternative approach
Consider a water leak and water use real-time monitoring system.
Resources & Studies
The Spruce: How to Test Your Home’s Water Pressure
Bob Vila: How to Find a Plumbing Leak
Verification
GreenHome Inspector will do leak inspection during final test and report results
The plumber working on the project may record water pressure and leak test results here.
Water Flow Rate Prescriptive Requirements
Certified | Silver | Gold | Platinum
There are two ways to get credit and meet requirements for lowering water usage.
Prescriptive Pathway
See below for maximum flow rates for desired level of certification. The Home Water Score Pathway, detailed below, is an option that considers other water-using devices.
This includes an average of all flow rates if multiple fixtures are present.
| Fixture | Certified | Silver | Gold | Platinum |
| Toilet* | <1.6 Gallons Per Flush (GPF) | < or = 1.3 GPF | < or = 1 GPF | < or = .8 GPF |
| Aerator Bathroom | 2.0 Gallons Per Minute (GPM) | 1.75 GPM | 1.00 GPM | .5 GPM |
| Shower Head | 2.2 Gallons Per Minute (GPM) | 2.0 GPM | 1.5 GPM | 1.25 GPM |
*Dual-Flush Toilets – When calculating the toilets, take the Low Flow Rate in GPF x 2 + High Flow Rate in GPF / 3 = # GPF to input. Example: .5 GPF low and .9 high = 1 + .9 = 1.9 GPF / 3 = .63
The performance path must be used to get points to consider efficient outdoor water usage through better landscaping, irrigation, greywater, and/or rainwater catchment.
Home Water Score Pathway
The Home Water Score, developed by the GreenHome Institute, is a calculator that measures water savings achieved through the use of low-flow fixtures and water-efficient landscape plans and/or rainwater catchments. The water usage is based on data from the ‘Residential End Uses of Water – Research and Trends’ study. The formula considers the number of people living in a home as the number of bedrooms, plus one. This number must be used instead of the actual or estimated number of occupants. The Home Water Score shown below must be achieved to gain the certification level listed:
Missing Dishwasher or Clothes Washer
If these items are not installed when the project is completed, and the score is submitted, the “worst-case” numbers are used; assuming the occupant will install a unit that is not Energy Star certified.
Outdoor Water Usage
This pathway requires the use of the Outdoor Water Budget tool from the EPA. Note that this tool has an online version that can only be used once and does not have the ability to save. The tool calculates water for all 12 months of the year, even in areas where the winter season eliminates the need to water. For this reason, the results may be divided into two for a more accurate estimate of outdoor water usage.
New construction projects must use the Outdoor Water Usage pathway, but it is not required for renovations that do not include any landscaping changes.
Xeriscaping or projects with no landscaping at all can keep the number ‘1’ in the first section and the ‘0’ in the 2nd for 100 percent savings.
Because the formulas do not calculate greywater or rainwater catchment, these are considered on a case-by-case basis.
Leaks
Leaks are assumed to either be 100 percent or none, meaning all leaks must be fixed. Typically, new construction has no leaks, though testing is still required.
Test leaks by taking the required pressure test reading with a pressure gauge, then make sure no water is turned on for 30 minutes. Check for a drop in pressure and see if the water meter moves.
For multifamily and homes with different fixtures in multiple bathroom, use an average of all the units together.
Homes with recirculation loops in faucets reduce water waste in those areas by 12 percent. Please inquire for special consideration if these are installed.
Resources & Studies
The GreenHome Institute youtube playlist on Water Conversation can help you save water, and it includes a 4 part series on how to use the Home Water Score.
Learn how to use the EPA Outdoor water budget tool
Products that can help
Niagara Conservation Stealth and Shadow Toilets ensure .8 gallon per flush toilets and are ADA compliant (though they have higher flowing toilets as well).
Verification
Photos and receipts of device installation. Flow-rate, leak test, and water test results. For landscaping, a landscape plan and plant list should be submitted.
Improvement Plus Program Only
For new construction and substantial rehabilitation, prescribed building water performance must be at least 10% better than the federal minimum requirements.
For existing buildings, project achieves a water use reduction of at least 10% compared with the baseline energy use based on recent 12 months of energy/water usage history
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