We have a debate going in our office about whether Sub-Meters are required (or Not) for the Option D - Whole Systems Simulation method. In LEED NC V2.1, sub-meters were explicitly required, but over the years things have changed....2.2 and 2009 have softened their requirements for sub-metering and they refer to the IPMVP Volume III for Guidance.

We've been doing sub-meters / sub-measurement on new projects because we think it is worth the cost; therefore we haven't even tried M&V without sub-subsytem feedback. We now have a commissioning agent that is seriously questioning our decision to sub-meter / sub-measure the project systems, but we think the project complexity warrants some feedback at the systems level and depending on the interpretation - that the credit would require it.

What is the general opinion? Are Sub-Meters totally up to the discretion of the team, on any project (excluding C&S applications)?

Is a high quality, calibrated energy model compared against the whole building meters one year after the completion of commssioning (along with a M&V plan and recommendations for improvements) all that is needed to earn Option 1 / D - no matter what?

And last but not least - Is the issue here really a language barrier around the definition of "Metering" and "Measuring" sub-system performance? I.E. Is 'Measuring' sub-systems potentially required?

Looking forward to the Opinions on this one...
Doug