Greenbuild Session Review: Cx & EM – Value, Cost and Project Integration

This session featured quite a few notable minds (the term “dauntingly prestigious” was used at one point) and featured some telling audience surveys, with a packed crowd (somewhere above 1,000) mostly but not exclusively composed of designers and engineers (many owners/facility managers included in the audience as well).

Energy Modeling

  • “Is energy modeling a necessary cost or mandate of LEED?” 70Y 20M 10N
  • “Is energy modeling too expensive for the outcome delivered?” 10Y 45M 45N
  • “Is the scope of energy modeling commonly understood?” 10Y 30M 60N
  • “There aren't enough energy modelers.” 70Y 20M 10N
  • “Energy modeling is not predictive of building performance.” 60Y 30M 10N
  • “There is no passive thermal modeling available.” 85Y 10M 5N
  • “Energy modeling increases standard of care for the design professional.” 50Y 30M 20N
  • “Energy modeling helps justify investments and convince clients.” 95Y 5M 0N
  • “Energy modeling supports integrated project delivery.” 75Y 20M 5N
  • “Energy modeling supports informed choices.” 90Y 5M 5N
  • “Most tools do not reflect the most innovative system designs.” 80Y 20M 0N

The end result of these survey questions was a discussion loosely focused around the following quote: ”Energy models are not particularly good at determining absolute energy use, but do a good job of comparing scheme A to scheme B.” This comment was quickly followed with a discussion about how we need tools to foster energy prediction. There is a strong need to get a detailed and ACCURATE understanding of the schedule of occupancy and how the building will be operated. Ultimately we have to model human nature (How far into Fall are you going to just leave the windows open instead of using a heater/AC? Is that typical?), and there aren't very good metrics or processes for getting this done.

When asked what the USGBC should due to respond to these issues, there was an excellent comment from the panel that right now all of the training is taking place in practice, and as a result there's no time for people to really explore and understand the software. There needs to be an emphasis on getting this training into the college degree programs where there aren't time (read: money) constraints. How the USGBC can foster this is up in the air. ”All of these comments have a common theme: a lack of consistent methodology.”

Commissioning (Cx)

  • “Cx is a necessary component/mandate of LEED.” 99Y .5M .5N
  • “Is Cx too expensive for the outcome delivered?” 0Y 30M 70N
  • “Is Enhanced Cx too expensive for for the outcome delivered?” 0Y 45M 55N
  • “Is Cx too poorly defined in scope to be properly implemented?” 50Y 0M 50N
  • “Are there too few qualified CxA?” 50Y 30M 20N
  • “There is no uniform certification program” 70Y 20M 10N
  • “Contractors don't understand Cx and as a result overcharge.” 60Y 25M 15N
  • “Costs are not standardized (all over the map).” 80Y 15M 5N
  • “Cx is the only way to ensure HVAC, lighting and other energy systems' installation are operating properly.” 70Y 20M 10N
  • “Cx improves project quality.” 95Y 4M 1N
  • “Cx reduces the liability of the design/construction team.” 50Y 30M 20N
  • “Cx saves the client more money than it costs to perform.” 70Y 25M 5N

”The M&V point is the most important LEED credit with regard to reducing the carbon footprint of a facility. The second most important point is enhanced commissioning.” The justification for this is that you can't improve what you don't track (M&V), and that the enhanced Cx credit requires that the CxA train the owner about how the building is to function. Comments from a CxA on the panel indicated he has found hundreds of overrides in retrocommissioning projects that are the result of a facility manager not understanding how their systems operate.

The other major discussion on this topic revolved around the fact that there's wide variability in the scope when all this is asked for in the RFP is to provide LEED fundamental/enhanced Cx services. Fundamental Cx was seen by commenters to be insufficient, as you're really only asking the CxA to provide the 'middle' of the services. They're brought in too late (no substantial design review) and leave too early (insufficient training and verification).

1 comment:

JR said...

Some interesting information...makes me want to get into Commissioning.