Unit 5. Net Zero Water Buildings
After completing Unit 5, students will be able to:
- Explain concept of Net Zero Water buildings
- Calculate indoor water demand of a building
- Quantify impact of conservation practices and technologies on indoor water demand
- Assess potential of Net Zero Water for a building
Context for Use
Description and Teaching Materials
- See Pre-Class Activity Handout (Microsoft Word 2007 (.docx) 20kB Sep13 15)
- Read "Water Conservation" by Joseph Bourg.
- This reading is a comprehensive summary of building water conservation practices. It is written from the perspective of large buildings/facilities, but the information translates to other applications. Reading and comprehension time estimated to be 30 minutes.
- Watch Video: U-Miami's New "Net-Zero Water" Dorm from P.W. Grosser Consulting.
- This video presents the University of Miami Net Zero Water dormitory. Video run time approximately 3 minutes.
- Students provide answers to questions listed in Pre-Class Questionnaire:
- In your own words, explain concept of Net Zero Water for buildings (< 3 sentences).
- Provide a list and one-sentence description of three best practices to help buildings achieve Net Zero Water.
(20 min) Lesson Intro and Discussion of Pre-Class Questions
a. Instructor states lesson learning goals to begin session and orients students to the topic and the lesson activities
b. Execute discussion of pre-class questions by recording student feedback on board, or in GoogleDoc for real-time sharing of responses
(10 min) Net Zero Water Activity: Part 1. Baseline Indoor Water Use Estimation
a. Student handout: Net Zero Water Activity Handout (Microsoft Word 2007 (.docx) 23kB Sep11 16)
b. Instructor presents overview of the LEED Indoor Water Use Reduction Calculator Spreadsheet LEED Indoor Water Use Reduction Calculator (Excel 2007 macro-enabled (.xlsm) 123kB Aug26 16)
1. Instructor resource provided to help explain activity, case study, and LEED Indoor Water Use Reduction Calculator:
2. LEED Indoor Water Use Reduction Calculator with possible answers is provided for instructors for Part 1 and Part 2:
c. Students work in teams of three. Need one laptop per team, and preferably each student has laptop/computer and works on their own LEED Indoor Water Use Reduction Calculator.
d. Student teams complete Part 1 of activity as instructed in the handout. Instructor may modify activity to use a local example.
e. Student teams report Part 1 results to instructor/class and instructor displays answers and reviews LEED Indoor Water Use Reduction Calculator spreadsheet to help students confirm their results.
(10 min) Net Zero Water Activity: Part 2. Reducing Indoor Water Use
a. Instructor guides students to complete Tables 3 and 5 from LEED Indoor Water Use Reduction Calculator spreadsheet to estimate the water savings from conservation practices.
(15 min) Net Zero Water Activity - Part 3: Evaluate Plan for Net Zero Water
b. Student teams select and enter their choices into the LEED Indoor Water Use Reduction Calculator following instructions in activity handout.
c. Student teams report results.
d. Instructor may wish to bring policy into the discussion by highlighting local or national standards for low flow water fixtures: Water-Efficient Plumbing Fixtures from the National Conference of State Legislatures (NCSL)].
a. Instructor reviews the Net Zero Water Check spreadsheet of the activity: Net Zero Water Check spreadsheet (Excel 2007 (.xlsx) 14kB Sep13 15)
b. Instructor should note that Outdoor Water Use is inserted already into the Net Zero Water Check spreadsheet. These values may be provided by the instructor from Unit 4, if the CME building is used for the case study in that unit. Instructors may also elect to have students apply the spreadsheet again, but this time to estimate outdoor water use for the CME building. Outdoor spreadsheets are provided for instructor use:
- Outdoor Water Use Spreadsheet - Blank (Excel 2007 (.xlsx) 12kB Apr9 16)
c. Student teams insert their annual indoor water use values for baseline and design scenarios.
d. Student teams evaluate the potential for the CME building case study to achieve Net Zero Water (teams should check their water budget — total the monthly differences).
e. Students report back to instructor. Instructor shares answers:
(18 min) Discussion
a. Individually, students are instructed to reflect on the exercise and record answers to the following:
(2 min) One-Minute Paper
1. Describe how to further improve the potential for Net Zero Water. Students might note graywater reuse, composting toilets, changing behaviors, etc.
2. Which months create a problem for Net Zero Water for this building?
3. Do you have a water surplus at any time to use for outdoor watering during the growing season? Would you need water storage?
4. If the CME building were in Atlanta, Georgia, how would the evaluation of Net Zero Water change? (students should refer back to Unit 3 and the discussion of urban climate)
a. Circulate the Minute Paper (Microsoft Word 2007 (.docx) 21kB Jul4 16) and ask for students to complete.
b. Instructor may summarize lesson briefly and point to learning goals, if time permits.
Teaching Notes and Tips
- Unit 5 can be adapted by replacing the CME Building Example with a local example
- An important part of Unit 5 is the potential to expand into more depth. For example, in a water resources engineering course follow-on units might go into more depth on the topics of water conservation, technologies, etc.
References and Resources
- EPA Best Practices for Water Management
- Living Building Challenge
- PDF Report on Water Independent Buildings (Acrobat (PDF) 1.3MB Sep13 15) by Central City Concern (March 2009)