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The IGCC is designed to implement green building on a massive scale--not to replace LEED.

There are many challenges with mandating daylighting within an international code framework. This illustrates one of them: geography plays a huge role in daylighting, but established climate zones do not overlap with daylight availability, so separate zones had to be established.

It's pretty exciting that local and state governments throughout the U.S. are leaping to adopt the International Green Construction Code (IGCC) before the code is even completed. That says a lot.

But as I sat down for Allan Bilka's talk about the code at the AIA Convention last week, one of his first comments said a lot too: "I think we're very far in any of these documents from producing a building that is truly sustainable." Ouch.

A lower bar, but more buildings

There's good reason for this, though. IGCC isn't meant to compete with LEED or the Living Building Challenge or any other rating system. It's meant to be an enforceable building code, a very different matter. Like it or not, if we're going to get control of climate change in the next few years, designing gorgeous new high-performance buildings is not priority one. Ho-hum buildings and ho-hum energy retrofits to existing buildings are going to be the bulk of the work.

Hence IGCC's "reasonable green requirements that could reasonably be applied to any building," in Bilka's words. "When you take elective requirements and make them mandatory, you have to ensure they can be applied in every building." He argued that achieving environmental benefits "on a massive scale" wasn't feasible using optional programs.

Some IGCC highlights

In this session, we mainly got an overview of IGCC characteristics along with some details about what the elective requirements were like, though Bilka also offered a couple examples of IGCC code requirements.

  • Buildings can take a prescriptive path (a "cookbook" approach following detailed specifications) or a performance path (a "measuring stick" approach meeting mandated targets), with the performance path required for buildings over 25,000 square feet.
  • The code consists mainly of mandatory provisions, but there are a few elective ones.
  • Of the elective provisions, some are chosen by jurisdictions (e.g., certain local governments may be more concerned about water use than others) and some are chosen by designers.
  • Even if something starts out as an elective, once a jurisdiction or designer chooses it, that feature is locked in as an enforceable requirement.

I asked Bilka afterward what incentive a designer or his client would have to choose an elective as a requirement. Currently there doesn't seem to be one--there are not various levels of achievement recognized, as with LEED's Certified, Silver, Gold and Platinum--but Bilka seemed interested in developing such possibilities in the future. For now, the committees are very focused on getting feedback on current drafts and finishing up in 2012.

IGCC vs. LEED: one example

How "green" are these requirements? While Bilka didn't stand in front and read the whole code to us (thank goodness!), he did give a few examples. Here's one: IGCC requires 50% construction waste diversion.

LEED for New Construction does not require construction waste diversion, but MRc2 is a commonly pursued credit. In order to get one point for waste diversion, 50% is the minimum, with more points for higher percentages. On the one hand, IGCC is more stringent--waste diversion is an absolute--but on the other, as discussed above, there's no built-in incentive to push beyond the 50%.

Daylighting: It's the law!

Later the same day, I went to another IGCC-related session that focused entirely on daylighting. Presented by Jack Bailey and Keith Yancey, AIA, P.E., this was one of the most entertaining and visually compelling sessions I went to--a lovely surprise at the end of a long day.

Bailey and Yancey shed a lot of light on the IGCC process and talked frankly about their own reasons for getting involved. They both felt that IGCC was going to be really influential in the coming years, but they didn't want an oversimplified energy story getting in the way of daylighting. Or, to put it another way, "We didn't want to see architecture go back to windowless boxes."

At the same time, they didn't want the code to cramp designers' style, so they wanted to have a hand in creating a code that would allow designers to be responsive to climate, would enhance energy performance, and would not prescribe solutions. In particular, they wanted to be very careful to create daylighting codes that would not be "a zoning ordinance in disguise." In other words, they wanted zero restrictions on urban infill, and the code includes exceptions for structures erected between two buildings that may completely shade the new building and prevent daylighting.

Quantifying the qualitative

One of the biggest challenges for this committee was getting past the fact that daylighting is really a design issue. It's difficult to write requirements for, and it's difficult to quantify its ineffable but undeniable effect on human health and well-being. "How can you mandate that?" the presenters asked. That may have started as a rhetorical question, but in the end they actually had to answer it.

People need windows in order to be healthy, and this committee was determined to ensure that people continue to get them, because "energy codes restrict daylight and do not value the IEQ aspects of daylight."

Turning daylight green

On the other hand, daylighting can save energy on both lighting and heating--if it's done right. So they focused on how to make sure it would be (without leaving out human health effects along the way). "Windows don't save energy," one of them quipped. "Automatic daylight controls save energy."

Although there are many ins and outs depending on building size and location, the daylighting section of IGCC requires 50% of a building's floor area to be daylit (with exceptions for things like restaurants). This is roughly comparable to the lowest option under LEED for Existing Buildings--Operations & Maintenance, where daylighting is a credit (IEQc2.4), not a prerequisite.

As Bilka pointed out, though, once you make it mandatory for every building, including existing buildings, you need to set a lower bar. Rating systems have done a lot to bring awareness and drive certain markets, but the vast majority of buildings aren't certified under such systems and never will be. IGCC is looking like a fairly stringent way to cast a wider net and capture more of our everyday building stock.

Now it's your turn

With Maryland and Rhode Island already on board along with local governments in New Hampshire, Washington, and other states, IGCC is certainly going to be an important part of many jurisdictions' climate change plans. Bilka, Bailey, Yancey, and hundreds of others have shaped it so far--and now it's time for others to get involved. Download the current version here. The public comment deadline is August 12, 2011.

*but not quite finished

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1 Is this "International" code posted by Jean Marais on 06/03/2011 at 05:43 am

Is this "International" code also usable outside the USA? That Daylightnig map looks very regional to me.

2 Jean - It is, though it is de posted by Mike on 06/08/2011 at 10:33 am

Jean - It is, though it is developed in the U.S., predominantly shaped by U.S. citizens, etc. My guess/hope, without looking, is that there is some kind of language in there for other countries.

3 Yes I agree with you that we' posted by Underfloor Heating Installing on 05/20/2011 at 02:24 am

Yes I agree with you that we're going to get control of climate change in the next few years and this is very good for us.

4 Amazingly, residential struct posted by Mike on 05/24/2011 at 12:37 pm

Amazingly, residential structures are not currently a part of the IGCC, so as it stands right now, it's only a commercial code. Residential buildings consume 3.3% more energy than commercial buildings, so there is a huge opportunity to make a positive change to our structures by adding them to this code. My organization will be working to do just that in Phoenix. If you'd like to assist in this effort, please contact me.

5 Mike, I'm a little late on th posted by Paula Melton on 11/08/2011 at 07:59 am

Mike, I'm a little late on the uptake here, but I believe IGCC does cover residential if it's three stories and up. Not sure if there are plans for a green home code or not, but I think it would look very different from IGCC if there were.

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