What IS a Green Building? (Part II - Benchmarking)

We previously discussed the importance of establishing measurable performance targets for green buildings.  As good as those are, they form an incomplete picture of green building design and construction.  What really brings context to the performance of a green building is when you take your performance metrics, and compare them against established benchmarks.

That's where green building design and evaluation systems come in;  Many people know about LEED, BOMA Green Globes, or ASHRAE standards.  These (and other systems and standards) offer baseline performance targets for your building project that establish how good (or bad) your building measures up against an agreed-upon base case. Let's look at a few examples:

LEED

The Leadership in Energy and Environmental Design (LEED) system is a set of quantifiable targets that evaluate your building against many of the performance targets we discussed last week.  The system uses a number of different approaches to bench-marking the targets, but offers a fairly comprehensive means of measuring how well a building meets sustainability targets, when compared to a "typical" building.  This "typical" building is a reasonable approach to defining what a building would perform like if built to the current building code.  That said, this claim is subject to much debate and variation from jurisdiction to jurisdiction, the intent remains as a comparison to run of the mill, no frills building.

ASHRAE

There are a number of ASHRAE standards that benchmark green building performance (some of which form part of how LEED works), but the fundamental approach ASHRAE takes is different than that of LEED.  Where LEED aims to benchmark buildings against established standards, ASHRAE attempts to establish those performance standards based on decades of measuring and evaluating real building performance.  As an example, the ASHRAE 55 standard takes something qualitative like "how comfortable do you feel in a room?"  and puts numbers and survey results to it so that real measurable results can be tracked quantitatively.

BOMA Green Globes, Toronto Green Building Standards, EnergyStar, and other systems all have different approaches to those mentioned above, but the point we are trying to reinforce here is that in order to get any value out of tracking measurable performance of green buildings, you need to have a benchmark "base case" to compare to, otherwise your efforts do not end up giving satisfactory context to see how well you have actually performed in constructing/designing the building.