Definitions and terms :

California Title 24 -2008 = California Energy code 2008 = CEC 2008 = CalGreen

HERS (Home Energy Rating) is a scale where 0 = zero net-energy, and 100 = average energy consumption in 2000. Its a good approach to resolves the issue of the moving baselines. Architectural Energy Corporation has written some white papers on the subject of energy code benchmarking for both residential and non-residential.


A historical footnote: CEC 2005 = ASHRAE 90.1-2007 = HERS 75.
ASHRAE 90.1-2007 and Cal Energy Code 2008 are NOT equivalent (as I had thought).

ASHRAE-90.1-2007 is the LEED benchmark, however, and LEED-NC requires a 10% minimum improvement. Therefore LEED-NC minimum = HERS 67.5

It is pretty common for LEED buildings to get a 20-30% improvement on ASHRAE 90.1-2007. Those buildings HERS rating = 59 to 52.5

CEC 2008 is CalGreen minimum = HERS 53. About the same as common results in LEED-NC

ASHRAE 90.1-2010 is approximately = HERS 50, (has not been adopted by anyone as of 12/31/2011).
CalGreen Tier 1 = HERS 45
CalGreen Tier 2 = HERS 37.

Summary

National Renewable Energy Labs says HERS 37 is the maximum technically feasible without resorting to onsite energy production methods. The rest of the way to net-zero needs alternatives to the typical gas/oil/electric regime.
Pretty stringent stuff that requires much due diligence. As you get lower and lower in energy intensity, envelope hvac, lighting types and process-loads become more important to the rating game. I am just skimming the surface here.

Here’s a good article on building performance. At the left is a graph: a picture worth a thousand words. There are links to many more reading sources on that page.

I think this covers it for now. Anything else you want to learn? Feel free to contact me.

The 250,000 sf World Wildlife Fund headquarters in DC is about to complete retro-commissioning and is applying for LEED-EB (Existing Building) certification. I managed and documented an “enhanced commissioning process” and have helped complete an application to the US Green Building Council for LEED certification that should land them the highest rating, Platinum. Also completed and finalized the commissioning of a LEED Commercial Interiors renovation project for the building. Lastly, I have just validated their U.S. Department of Energy – Energy Star application for the entire building, with a rating of 86 (based on 100).

Another recently completed commissioning job included 80,000 sf of new interiors for the European Commission in DC.

I am providing this service as a contractor to CPM Scheduling, LLC. CPM is a highly respected and growing LEED commissioning consultant that has successful work in over a dozen states from Colorado to the East Coast. I currently act as Senior Commissioning Authority on their behalf.

I have a half dozen other projects, encompassing at least another 600,000 sf, in various stages, and as they are completed, I will tell about them here.

Here is a flow chart that I like. Charts are great for reducing complicated processes down to one glance… I like a good flow chart because they are visual, and I tend to be visual, maybe because of my defective ears.

This chart was borrowed from ASHRAE by the National Institute for Building Sciences (NIBS), and is posted on their Whole Building Design Guide web site. Click on the thumbnail to see the full size version.

An excellent commentary in this months Engineered Systems magazine, entitled Tomorrow’s Environment: A Failure to Plan Is A Plan To Fail by Howard McKew, exposes the weak link in the chain between energy efficient design and the long term operation and maintenance of said design. How do we know they are getting what they paid for?

Too often, we don’t know. McKew explains that measurement and verification is often left out of the design due to budget constraints. I think operations often falls under the radar for lack of understanding the need for verifying. And CMMS software, intended to help rectify this problem by making it easier to manage and maintain the many moving parts of a building, apparently doesn’t get used!

I have mentioned ACCOUNTABILITY in previous posts, and here is another sample of what I am talking about. My worrying is well-founded. Filters need to be changed, pump bearings need lubricating, dampers need to be observed in operation, temperature sensors need to be calibrated and so on. HVAC, even when it is designed to be as simple as possible, is still complicated in practice.

LEED certified office buildings excel

Additional editorial on LEED and Energy Star marketability