The Cost of LEED Review: Relatively Great, Specifically Problematic

A few weeks ago I was provided with a copy of The Cost of LEED whitepaper ($49 + shipping) from BuildingGreen*, and I must say I'm impressed. The report is by no means flawless, but it's the first one I've seen that provides designers with a credit-by-credit 'back of napkin' figures to use to calculate cost premiums for various design strategies.

To my knowledge the only thing that even comes close is a useful but (in some ways) less detailed study from the GSA in 2004. It's worth noting that the GSA study is free, but is limited to GSA office and courthouses for its scope and does not list specific construction cost premiums for each credit. Let's take a look at a sample page from the BuildingGreen report to get a feel for the document and then I'll offer up some pros and cons:

Sample Credit Report for WEc3 - Click to view Full Size - Reprinted With Permission

This profile of credit WEc3, Water Use Reduction is fairly typical... setting 'conventional' systems as the cost baseline and indicating specific premiums for various upgrades that may be used when pursuing the LEED points. It's important to point out that this is probably one of the longest credit reports in the whitepaper, as more than a few strategies (e.g. SSc1, Site Selection or SSc4.1) are so dependent on local site factors as to be unquantifiable in any realistic sense. Assumptions are pointed out when appropriate and in general I feel like you're provided with enough information to make adjustments on the fly if you have strange circumstances. The report only covers the LEED-NC v3 rating system, so if you're pursuing anything other than LEED-NC or LEED-CS this report will be of limited value.

Cons

I see two major problems with this whitepaper. The first and most significant is that soft costs of LEED (energy modeling, documentation fees and the like) are not provided. I think the soft costs component of LEED premiums have not been discussed sufficiently as an industry, and from my limited experience I've found fees still vary significantly from consultant to consultant. I would have greatly appreciated a section that attempted to provide some ground rules for costs from civil engineers, MEP engineers, architects, contractors, specialty LEED consultants, etc. It's worth noting that commissioning costs are the exception to this rule and are included in the report. It's also worth noting that the GSA study takes a stab at soft costs (see page 6), though it lumps all parties into a single figure that isn't terribly useful.

The second lies in the accuracy of the specific costs listed for each specific measure, and I could be off base about this. Not being a cost estimator myself, I've taken informal polls from a few people in design and engineering fields locally, and the consistent response is that the costs 'seem high'. I think this is likely due to the fact that "cost data is based on northeastern US construction costs from 2008." I'm in South Carolina, and it only stands to reason that everything would be cheaper here, but that doesn't change the fact that those costs would likely need to be adjusted across regions and time. In their defense, these issues are presented right up-front in the Assumptions and Qualifications section.

Pros

Ultimately the strength of this report lies in the "Construction Cost - Relative Percentage" tabs for every credit. The simple multipliers allow you to consider the impact of adding credits early in the design phase, and the Cost Synergies section helps ensure you're not making those decisions in such isolation as to not understand the impact on other points you may be considering. It allows you to have an answer, however rough, when a client asks you a question like, "How much would it cost if we decided to switch from our dark roof to a light TPO membrane?" The use of concise charts allow you to do this in a report that is only 47 pages, yet at the same time it includes at least one strategy I haven't even heard of (e.g. aircuity systems).

*FULL DISCLOSURE: BuildingGreen operates LEEDuser.com, a sponsor of this site. The copy of the Cost of LEED report was provided free of charge for review purposes. That said, I stand by the review I've posted as an accurate and un-biased portrayal of the report's value, and I would make the same report even if LEEDuser were not a sponsor of this site. If you feel I've overlooked or omitted anything important please speak up by leaving a comment!

Key Baseline Changes in 2009 Edition of WEc3, Water Use Reduction

I recieved a call from a project architect this morning who had designed a large LEED Core and Shell v2.0 project who in turn had received a call from another architect who is working on a LEED Commercial Interiors v3.0 (2009 edition) upfit of the same building. While we were able to earn 2 points for reducing expected water use by 30.1% in the LEED-CS submittal, when the upfit architects were looking at the water use reductions based on the LEED-CI requirements they determined that the anticipated reduction was only 10.8%. This level of reduction doesn't even meet the new 20% reduction requirement found in the WEp1, Water Use Reduction prerequisite!* What happened? Did we miscalculate the original submittal?

The Unusable Faucet... The latest in water use reduction technology

We (or rather our consultant engineer) didn't miscalculate anything! After taking a closer look at comparing the calculations for both the v3 and v2 editions, we discovered that LEED has adjusted the baseline rate for public faucets from 2.2 gpm down to 0.5 gpm, meaning that while we had substantial flow rate reductions in the LEED-CS v2.0 submittal, none could be claimed for the LEED-CI v3.0 calculation even though the fixture specs were the same. The updated baseline standard applies to v3 editions of LEED-NC, LEED-CS, LEED-Schools, and LEED-CI systems. The change stems from the inclusing of the "maximum [flow rate] incorporated into the national Uniform Plumbing Code and the International Plumbing Code[s]" into the updated requirements. LEED-EB:OM v3.0 sets the anticipated baseline on these standards, but that was the case on the v2 edition as well so nothing has changed there from what I can see.

While the v2 baselines applied a 2.2 gpm baseline requirement for all bathroom lavatories, the v3 system distinguishes between 'public' and 'private' commercial restrooms and residential bathrooms. A private restroom is anything that would regularly be used by only one person at a time: hotel/motel guest bathrooms, hospital patient room bathrooms, and arguably bathrooms serving single offices (e.g. bathroom in the CEO's office used only by that person). All residential bathrooms and these private bathrooms are still held to the same 2.2 gpm baseline as before. Everything else (hotel lobby, shared office, school, and retail and restaurant bathrooms, etc.) are now held to the .5 gpm baseline.

I should point out that I think this is a good change... it's ridiculous to put anything other than a .5 gpm in sinks that will likely never be used for anything other than handwashing or perhaps brushing your teeth, especially when you consider a .5 gpm replacement aerator costs about $2. It also makes sense to keep private bathrooms to a higher standard, since people may be filling coffee pots or other containers that could be annoying if you were limited to such a low flow rate. I've installed a variable flow rate faucet in my kitchen that works great since I leave it on the low setting until I need to fill something up, but my bathroom sink uses a .5 gpm aerator. I should point out that people using on-demand water heaters may have problems in that the flow rate is so low that it may not trigger the water heater to turn on!

Bottom line... I think this is another instance of LEED moving in the right direction by tightening the requirements a bit, but people used to the v2 systems such as myself should definitely make a point to realize that a 20% reduction in v2 is not necessarily 20% in v3. Disagree with me? Please let me know by leaving a comment!

*I should note here that as the bathrooms in question are part of the shared core space of the facility, they should presumably not impact the LEED-CI calculations at all since they are outside of the scope of the upfit**, but any project that upgraded or is considering upgrading from a v2 system to it's v3 equivalent should take note of this change and evaluate the impact on their scores and ability to meet the WEp1 prerequisite.

**NOTE - 02.17.10 - Nathan has questioned the accuracy of the assumption that the existing fixtures would be outside of the scope of the prerequisite in the comments, and I don't have an 2009 IDC reference guide on-hand to refer to so I can provide a definitive answer. I've always been a little hazy on how the scope of a LEED-CI project is set, and since I don't have direct experience in LEED-CI I could very possibly be wrong!

FREE Online LEED Water Use Calculator

If you haven't found it already, Zurn has an online water use calculator that features a LEED option for comparisons. It allows you to quickly check the difference between various efficient fixtures for Water Efficiency Credit 3, Water Use Reduction. It isn't perfect (doesn't show total use reduction percentage), but it's extremely quick. It allows you to pick your scope (ie... if showers aren't in the project you simply don't include them), and the baseline fixtures are already loaded for you!

Zurn Water Calculator

I could explain further, but just check it out yourself! Know of a better resource available for checking water use please share by leaving a comment.

Determining Occupancy: Residential Edition

My last post on determining occupancy for LEED projects did not discuss how to determine residential occupancy, an issue I've encountered recently.

Searching through the Credit Interpretation Rulings, I found a rather vague answer coughed up by the supreme court that is the CIR council (committee? emperor?) dated 2/14/2007:

Per the LEED NC v2.1 SSc4.2 ruling dated 12/9/2005, occupancy should be calculated using the number of bedrooms in the case of residential projects. Project teams should provide a narrative with calculations demonstrating how the total number of residential FTE occupants was calculated including indication of number of units, size of units (e.g. studio, one bedroom, two bedroom, etc.), and assumptions as to number of occupants per each size of unit.

So we base it on bedrooms... great! It would sure be nice to have actual guidance on how to transfer that into a hard number, but why make it that simple? Now we get into the sticky issue of what number to put to what bedroom count. Being lazy, I did not take the time to research average occupancy across the nation or anything like that. Instead I proposed the following:

Residential Occupancy Per Bedroom

• Studio/1 Bedroom - 1.5 occupants
• 2 Bedrooms - 2.5 occupants
• 3 Bedrooms - 3.5 occupants
• 4 Bedrooms - 4.5 occupants
• etc.

Being the smart guy or gal that you are, you've probably picked up on "the formula". I think it's a safe bet to assume that a one bedroom could equally be expected to be occupied by 1 or 2 people, so I split the difference and assume 1.5. For additional bedrooms, it's likely to be occupied by either kids or roommates, but doubtful it will be occupied by additional couples.

I'd like to be clear that this assumption has not gone off for review yet, and I'm not going to spend a few hundred dollars to answer the question beforehand... I think this argument is reasonable, and expect it to be accepted, but don't want you to stake a large quantity of money on the fact that I'm right. If you have used different assumptions that worked or tried this one and failed, PLEASE be sure to comment on your experience below. Thanks!

Determining Occupancy

So we need to know our occupancy for our nice LEED project... great. This question bothered me for a long time, especially since it affects so many credits. Then I realized you're basically supposed to make it up! Really though, the owner is supposed to supply you with the numbers, but how is he going to do that if they're not sure? If you're working a core and shell project that fits neatly into the groupings below, you can use the default occupancy numbers (in square feet/FTE) below. Most credits is defined as SSc4.2, SSc4.3, SSc4.4, EAc1, EQp1, EQc1, EQc2, EQc6, and who could forget, EQc7. See the LEED-CS reference guide (page 441) for more detail.

If you're not fitted nicely into one of those groups, you're on your own. I take the code occupancy count and break out the reasonably inferred FTE. If you have a restaurant, there are only going to be so many cooks in the kitchen, tables per waiter, a hostess, a bartender, and a manager. I would then subtract that number from the code occupancy to give me the transient loading, which would be added to the FTE number to determine peak loading. In a mixed-use project you would need to look at hours of operation - as peak loading for a movie theater is likely to be on a different schedule than peak loading for an office. See below for an example breakdown for SSc4.2, Bicycle Storage and Changing Rooms.

Am I wrong in my assumptions? TELL ME! Please use the comments to make this site more informative!