Expert Advice by: Sarah Gudeman, LEED AP, EIT,
Morrissey Engineering, Inc.
Location: Omaha, NE

Website: http://www.morrisseyengineering.com/
Phone: (402) 491-4144

Sandra asks: Do you know the cost differential between USGBC LEED-NC v2.2 and USGBC LEED-NC v3 to hit Silver? I know that it will depend on the circumstance, but are there any ballpark numbers?

Answer: Sandra, of course you’re right, the cost differential will depend on the circumstance. At first I know that the conversion from LEED-NC v2.2 to LEED Green Building Design & Construction (aka v3) is a daunting one and it would seem more expensive at first glance. There are 110 possible points available in v3, versus the 69 previously available in v2.2 and there’s that new credit category (Regional Priority, more on that is available in other posts). But in essence, the changes made aren’t as drastic as you might think.

So in terms of cost differential for documentation in a v3 project versus a v2.2 project, the old way or estimating cost or hours ‘per credit’ kind of goes out the window… of course a 1.6x weighting factor could also be applied, but this isn’t a math exercise. So let’s assume that documentation costs stay roughly the same. These costs have potential to vary across the board anyway and I’m guessing it wasn’t the true intent of your question anyway.

Fundamentally I would say that anyone who’s worked on a LEED project certified under LEED-NC v2.2 shouldn’t have any issue with working on or documenting a LEED v3 project, assuming they have access to the new Building Design and Construction Reference guide, as well as associated updated referenced standards. A good example of such a small change would be the requirement to comply with ASHRAE Standard 90.1-2007, as opposed to the 2004 version referenced in the New Construction v2.2 Reference guide.

This example is convenient because it’s also the change that has potential to make the most impact in cost. We all know – I assume – that EAc1, Optimize Energy Performance (aka, the big credit) caries the most weight. In v2.2 it was worth over 14% of possible points and in v3 it’s worth even more at 17%. This credit references ASHRAE Standard 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings (with errata but without addenda) to ‘achieve increasing levels of energy performance beyond the prerequisite standard to reduce environmental and economic impacts associated with excessive energy use’. This energy performance comes from three main categories: building envelope, lighting and HVAC system.

It probably goes without saying that the 2007 version of the standard is more stringent than the previous version, but the tough question is how much so… The Architecture 2030 challenge helps in this with their 2030 Target Table, available at http://architecture2030.org/downloads/2030_Challenge_Targets_National.pdf. (Here I’ll have to thank Joel over at www.reallifeleed.com again for this).

Turns out that exceeding the 2004 standard by 30%, and exceeding the 2007 standard by 25%, are both roughly equivalent to the interim 50% goal of the Architecture 2030 challenge. Assuming this equivalency is correct, than a building that earns 6/10 ( EAc1 points under v2.2 would earn 7/19 points under v3 and the 2007 building would be approximately 16.7% more energy-efficient than the 2004 building. To get this increased efficiency you’d have to make the three items noted above that much more energy efficient. So, to wrap up a long answer to a short question, I’d ballpark that if your project carries a EAc1 cost premium of $50,000 (this is above and beyond your budget pricing for minimally compliant systems), than the equivalent v3 project would correspond to the same increase (maybe up to $10,000).

So to sum up, I don’t believe the change to a new rating system puts a cost premium on LEED any more in version 3 than in previous versions. Because even if the project weren’t pursuing LEED certification, code compliance requirements are also being updated and upgraded so baseline requirements to meet code are also increasing – and come with their own cost premiums as well.

Advice provided by: Sarah Gudeman, LEED AP, EIT, Morrissey Engineering, Inc.
Location: Omaha, NE

Website: http://www.morrisseyengineering.com/
Phone: (402) 491-4144