EBOM 2009 WEc2: Additional Indoor Plumbing Fixture and Fitting Efficiency

Dan Ackerstein replied Principal, Ackerstein Sustainability, LLC Dec 23 2009

My understanding of that notation in the Reference Guide is that it allows for the consideration of exceptionally low-volume appliances in the context of an Exemplary PerformanceIn LEED, certain credits have established thresholds beyond basic credit achievement. Meeting these thresholds can earn additional points through Innovation in Design (ID) or Innovation in Operations (IO) points. As a general rule of thumb, ID credits for exemplary performance are awarded for doubling the credit requirements and/or achieving the next incremental percentage threshold. However, this rule varies on a case by case basis, so check the credit requirements. credit.

However, it should not be read to *require* the inclusion of those appliances or similar in the calculations for WEp1, WEc2, or an Exemplary Performance credit. A building can certainly earn any of the above without addressing such appliances; the standard suite of fixtures are what dictate performance.

Jason Franken replied LEED Consultant, YRG sustainability Jan 29 2010

The language for this credit is notoriously confusing, so thank you for helping us to fine-tune our explanation! There are several options to document compliance with this credit depending on the age of the project building and/or plumbing system.

If your building was completed after 1/1/1993, it is assumed that it meets all relevant UPCUniform Plumbing Code/IPCInternational Plumbing Code codes and you can earn one point without performing additional calculations.

The same situation applies if all relevant building fixtures/fittings were replaced after 1/1/1993.

If your building was completed before 1993, you need to use Option 4 to analyze all of your building fixtures and use the data to calculate the potable waterPotable water meets or exceeds EPA's drinking water quality standards and is approved for human consumption by the state or local authorities having jurisdiction; it may be supplied from wells or municipal water systems. consumption and compare it to the LEED baseline.

As you've pointed out, the baseline is calculated at 160% of UPC/IPC codes for pre-1993 fixtures and 120% for post-1993 fixtures; if your building has fixtures from before and after 1993, a weighted average is used to determine the LEED baseline.

So, the credit option is designed to help you account for older and newer fixtures and develop a comprehensive picture of potable water consumption, regardless of whether your building was completed prior to 1993.

Jean Marais replied b.i.g. bechtold INGENIEURGESELLSCHAFT MBH Mar 11 2010

...mmm...different countries have different codes also at different times. just food for thought.

Jason Franken replied LEED Consultant, YRG sustainability Mar 11 2010

Rachel, the diagram has been revised recently, so please take a look and see if it makes more sense now. The previous diagram did not accurately explain the distinction between the different baselines. You only need to think about this issue with the baseline if you're using the Option 4 compliance path and doing performance calculations and even then, the LEED credit form does all the work for you.

Buildings that were built before the Energy Policy Act of 1992 had different building codes to follow. It's assumed that they have fixtures that use more water, so LEED uses the higher baseline (160%) when performing calculations to allow them more breathing room. So, if your building is pre-1993, the higher baseline is used and if it is post-1993, the lower baseline is used. Another common scenario is a pre-1993 building that has some of the original fixtures and others that have been retrofitted in the last 15 years; in this case, the baseline is pro-rated to be somewhere between 160% and 120%, based on the relevant number of fixtures and when they were installed.