US Green Building Council LEED-AP-ID+C Exam - Topic 4 Question 17 Discussion

Actual exam question for US Green Building Council's LEED-AP-ID+C exam

Question #: 17
Topic #: 4

A renovation project includes both a new kitchen sink and shower and an existing lavatory and water closet within the LEED project boundary. How would the project perform the Water Efficiency Credit, Indoor Water Use Reduction calculations?

AInclude only the newly installed fixtures and exclude the existing fixtures

BInclude only the existing fixtures and exclude the newly installed fixtures

CInclude all fixtures (new and existing); the baseline for the existing fixtures would be the flush/flow rates of the existing fixtures prior to retrofit

DInclude all fixtures (new and existing); the baseline for the existing fixtures would be the same baseline flush/flow rates used for the new fixtures

Show Suggested Answer

Suggested Answer: D

For the Water Efficiency Credit, Indoor Water Use Reduction calculations, all fixtures within the LEED project boundary must be included, both new and existing. The baseline for the existing fixtures should be the same as the baseline flush/flow rates used for the new fixtures. This approach ensures a consistent and fair comparison between the current and proposed water use.

LEED v4 ID+C Reference Guide1

Indoor Water Use Reduction Calculator instructions2

LEED v4 water efficiency credit requirements3.

by Andra at Aug 16, 2025, 03:34 AM

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Cherry

2 months ago

Definitely C, that’s how you get a true picture of water use.

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Janna

3 months ago

C seems right, but I'm surprised it's not just about the new stuff.

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Helaine

3 months ago

No way, I’d go with D. Makes more sense to use the same baseline.

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Marshall

3 months ago

Really? I thought they’d only count the new fixtures.

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Jamal

3 months ago

I think it's C, gotta include everything for accuracy.

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Carole

4 months ago

I believe we have to include all fixtures, but I’m not clear on which baseline to use. It seems like option C might be the right choice based on what we studied.

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Justine

4 months ago

I’m a bit confused about whether to exclude the existing fixtures or not. I feel like including them makes more sense for a comprehensive assessment.

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Hyun

4 months ago

I remember a practice question that mentioned using existing fixture rates for the baseline, so I’m leaning towards option C.

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Olive

4 months ago

I think we should include all fixtures for the calculations, but I'm not sure if the baseline should be the existing rates or the new ones.

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Isidra

4 months ago

Easy peasy! The question clearly states to include all fixtures, so option D is the way to go. Gotta love when they make it straightforward.

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Giovanna

5 months ago

Okay, I think I've got this. The key is to include all fixtures, both new and existing, and use the appropriate baseline for each. Time to put pen to paper and work through the calculations.

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Dwight

5 months ago

Hmm, I'm a bit confused on how to handle the existing fixtures versus the new ones. I'll need to re-read the question and think through the LEED guidelines.

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