Dan Jacobs

Dan Jacobs, AIA
A3C Collaborative Architecture
Ann Arbor, Michigan

Tottered on: 21 May 2008
Temperature: 49 F
Ceiling: bright but cloudy
Ground: green roof!!
Wind: NW at 12 mph


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TT with HD: Dan Jacobs

a3c green roof
Totter 2.0 on location on top of the green roof
A3C Collaborative Architecture

[Ed. note: The final touches haven't been put on the decking to the UrbEn Retreat, the newly built structure behind HD and Dan.

It's worth taking a close look at the skylight nearest to the totter to see why HD is especially pleased with this photo, which was taken by Charles of A3C.

More documentation on the green renovation to their office space undertaken by A3C is available on their website.]

HD: Okay, so shall we actually do some teeter tottering up and down?

DJ: Sure!

HD: You don't have motion sickness or any other issues?

DJ: Not yet.

HD: Not yet? Have you in the past? [laugh]



DJ: No, actually I'm a great teeter totterer, and when we were growing up in Vermont, we had a teeter totter by the summer cottage. And it was well-used! Later on when we had children I got back into teeter tottering. It's been about 15, 16 years since I've had a chance to do this.

HD: Ah, okay and so, growing up in Vermont did you actually call them 'teeter totters', or did you call them 'sees-saws'?

DJ: We used to call them see-saws back there. Exactly.

HD: So it was very polite of you to actually adopt my preferred terminology!



DJ: I have been working on it. [laugh] It's been real hard. Sort of like 'soda' and 'pop', too. We had to kind of get those East and Midwest kind of terms correct, so.

HD: So you think of yourself as still sort of an Easterner who happens to live in the Midwest or do you sort of feel like, yeah you're from here now.

DJ: That conversion occurred probably about 10 or 15 years ago. And we have now been in the Midwest for 34 years, and in the other parts of the world about 24 years.

HD: So on balance ...

DJ: ... so we are over the balance point, yep!





HD: Let me ask you specifically about the geothermal system. One of the data points that I find fascinating is the 400 feet figure. Why on earth you need to go down 400 feet? Do you have to go down that far to get the temperature right, or is it a matter of the length of the well--so for like surface-area issues?

DJ: More the surface area. The 'wells' are not 'wells'--they are actually 'bores'. I think people sometimes get this belief that these things are connected to the ground, that somehow you're putting a fluid into the ground. We're in a closed loop--it's called 'closed loop earth-coupled geo system'. What that means is, the pipe goes down and the fluid never actually leaves the pipe. That's very important. A 'well', I think there is an interpretation that there is an opening on the other end of the pipe. Ours is not.

So first off, the reason for 400 feet is that in an urban environment, we just don't have a lot of area for our well field. I'm using the term again! And what's required is a certain lineal footage of pipe area so that heat can be transferred out into the earth as a storage mass for that. Initially we were looking at six of these bores going down about 400 feet. And the particular system that we actually ended up with has an efficiency that literally allows us to remove a third of those bores down into the earth.

HD: So you did six but you're only using four? Or you just realized ...



DJ: ... in the original design using conventional geothermal systems, we would have had to have done six. That particular company, Hardin Geotech, actually has proprietary pipe that is so much more efficient that it allowed us to reduce the number of bores.

HD: Efficient? So like at heat exchange?

DJ: Exactly. The main concept of traditional geothermal systems is two pipes that are literally put together at the bottom of the pipe, so they are running down side-by-side. So you imagine that I'm putting a hot fluid in one pipe, trying to shed that heat out into the earth, and then at the very bottom hopefully, it's going to turn around and start getting rid of that heat, starting to get cool. Unfortunately, as you start moving back up the pipe, the hot pipe is there right beside it, so instead of shedding heat anymore, you are absorbing back the heat from the pipe that is going down. So the efficiency is not particularly good.

The new designs for this other pipe have two half circles separated by some insulating medium. So the fluid goes down on one side, shedding heat out on that side, and as it comes back up on the other side, it's isolated to a certain degree by the medium from the other side. And the design of that pipe also allows us to put a slurry mix out, and it fills the void between the pipe and the original bore that was done for sending it down. And that slurry mix provides us then with a good contact between our pipes and the bedrock that is down there.

HD: So that surface area contact then is basically a perfect interface, because you filled it in.

DJ: Exactly. And we avoid all of the voids that would be in there if we didn't do it that way. And we make sure that we have really good transfer.



HD: You said bedrock. You know, I was walking along First Street in Ann Arbor here yesterday, and I encountered a woman who was digging a rain garden. I mean, she wasn't going down to bedrock level, but it was kind of interesting, she was down far enough that you could actually see the striations. So the top layer was like cinders, because that's what they put down for the driveway, and then you can see this clay layer. How far down do you have to get before you hit bedrock in Ann Arbor?

DJ: She would have to dig her whole house to about six times to get there! It's about 150 feet in the area that we are in. Basically Ann Arbor, as you get up into the downtown business area, is essentially a glacial fill. So for the top 150 hundred to 125 feet, depending on where you're at, is all sort of a gravelly kind of mix left over as it came through. And what happened, of course, is that the Allen Creek rinsed away some of that to create this valley effect. We go down 150 feet of basically that gravel, and then we get the next 250 feet bedrock.

HD: So how long did that drilling take? Was that an afternoon deal, or did it go on for days and weeks?

DJ: I can tell you that the neighbors would have liked it to have been a week!

HD: [laugh]



DJ: But it went a little longer than that. The process of drilling itself probably took a week and a half to almost 2 weeks by the time we got it done. It would not have taken that long in a non-urban environment. But in an urban environment, the challenge is that as they're drilling, they're actually using some water down there keep the drilling device cool. And then as it comes up, it's dragging some of that mix of the earth that was in there up and out. Well, we can't just let that water with a gravelly mix just go anywhere. So we have to actually bring water in in tanker trucks, and we have to pump it back out in other trucks. That process of moving that material in and out adds to the time factor.

HD: Got it. So when you guys were actually drilling then, you were drilling in the usual way you would drill wood, in that there is the equivalent of sawdust? In other words you didn't end up as a byproduct having these cores as souvenirs or anything?



DJ: That's correct. That's right. It would have been nice, and actually we talked with a couple of different departments around the city and the county, who would have loved to have seen core samples. But what we were able to do is use our drilling logs to at least let them know when we went from one type of material to another, so that others that want to go after us in doing this will actually have a good feel for what they are going to find. And now there has been a subsequent building that has been done on the corner of Ashley and Washington, and now we have new data for that location as well.

HD: Okay, I was going to ask you if maybe that's what that was. I saw this huge--it look like a drilling rig to me, so they are doing a geothermal installation?

DJ: That was their test well. They call it a test well, or a test bore, to actually determine where is it that they're hitting bedrock, and what is it that the other materials are. Because if you're in a more traditional location, other than in downtown Ann Arbor where we have a good feel for what things are, you might encounter a water level, you might encounter gravelly mix for a longer period of time, you might encounter a mud level--a bog type thing--each one of those has a different thermal-dynamic characteristic. And how much pipe you need is based off of what those characteristics are.



HD: So I read that this geothermal system, you can anticipate that it will actually pay for itself like between six and eight years from now?

DJ: Now, I think probably to be fair, if we were to build a new building it would be a six- to eight-year kind of payback on it. Our building--because we were replacing ductwork, we were doing a bunch of other things--would be a longer payback than that. Whether it would be a traditional system or a geothermal system, it would have a lot larger costs. The incremental difference in there will get us in about a 10-year payback. It was still a sizable chunk of money to do the geothermal system. That was just inherent to the fact that we were renovating the building.



HD: So in order to do the calculation on that payback for a geothermal system, seems to me that is something you can actually measure in dollars and cents. But you talk a lot about this Triple Bottom Line--profit, people, and the planet. So for some of the other aspects of this building renovation, the stuff that doesn't involve the geothermal system per se, like a green roof, or the materials you are using inside that have less--what's it called--off-gassing?

DJ: Correct.

HD: Those kinds of things sort of accrue more to the people and the planet aspect of the Triple Bottom Line. And I'm wondering, have you developed like a calculus for computing that? Or is it more or less along the lines of, We just need to think about these things? I mean, how sophisticated is this notion of the Triple Bottom Line? Do you have like a way of computing a score--like the profit score is this, and the people score is this other thing, and the planet score is whatever it is, and we threw it all together, and we say, Oh, We're greater than 50 on our scoring matrix, and therefore we are going to go forward on this project.



DJ: We didn't go out with the assumption that we were going to try and hit a score. The firm has always been very committed to sustainable design. Originally my firm when I started was Environmental Structures. That ran for two years before I merged with another friend. A lot of the early work was in passive and active solar systems, earth-coupled systems, insulated buildings, and that was the core of where we were as a firm. And what we did here was, we went back and we said--probably two years ago I went to an AIA conference, William McDonough was there speaking ...

HD: ... oh, this is the Cradle to Cradle guy?





DJ: That's it, exactly. I had certainly read enough material about him before. We had always had been encouraging our clients to do buildings that were more energy-efficient, try to find ways to make sure the buildings were healthy. But I came away from that session feeling that as a firm, we needed to become more advocates. So what's happened with our project is we have done a lot of it in the area of research and also demonstration, so we can allow people to see how these different systems can benefit them in different ways.

So back to your Triple Bottom Line. There is a matrix that you can create for each one. Obviously, what we do for the planet is our carbon footprint. The carbon footprint of our building has been significantly improved--our building uses 47.5 percent less energy in its operation than a conventional building that might be designed to what they call ASHRAE [say: /ash-ray/] standards. That's sort of the national guideline for designing buildings, mechanical systems, electrical systems.

HD: And what is the name of that again?

DJ: ASHRAE. American Society for Heating Refrigeration Air-conditioning Engineers.

HD: All right! [laugh]



DJ: So first off, you have to get your energy level down. Between all of our lighting and the day-lighting and our geothermal system, we are able to take care of that sort of thing. Secondly, you can use satisfaction surveys. Essentially you list people's happiness with their particular workspace they've got now--what is it they don't like, what is it they do like about how it is--and then you go back after that and assess that. We did not do that sort of assessment in our case.

We have been in conversation with our staff for over 3 years--what are their priorities, where are the top five things that they would really like to see done with the space, and those are the things that we attacked. And so we made sure that all of those things were components of our design. And because in an office environment like this, over a three-year cycle, some of the people who were there making those judgments then, versus who's here now, is a different mix.

So we felt pretty comfortable that we got at least those top five areas covered carefully. And I think if you ask any one of our staff members about the environment that they were in eight months ago, and the one that they are in now, that the satisfaction level is way high.



HD: You mentioned the desire to create a place that was a demonstration for folks. And we are sitting right next to what's called the UrbEn ...

DJ: ... UrbEn Retreat.

HD: UrbEn Retreat, right. And this is available to government and to nonprofits for free?

DJ: We have a group coming in Thursday night to hold their board meeting, actually. I think it's Recycle Ann Arbor, they are having their board meeting here.

HD: Are they really?!

DJ: And we've had Google's Green Team, they held their Green Team retreat here. So we've had a number of different groups who have come in and utilized the space already. That's the long-term goal, that that will continue to occur. Right now we're giving tours to probably about 4 to 6 people or groups every week, or every now and then people who just call in out of the blue to see if they can just come in and see what's going on.

HD: Wow. So at this point there is not a scheduling issue? But at some point, you know, it could be! It could become an issue that you've got actually ...

DJ: ... it could be that we would actually have to tell somebody--we would hate to have it happen--we could get to a point where we might have to tell someone, no, you can't use the space. We actually set up our entire circulation system so that a group can come in on off hours, we can lock off the rest of our workspace from the staircase, and they can come in and meet here without us being around to keep an eye on what's going on.

HD: So they don't have to feel like, Oh, we're intruding into somebody else's space, into somebody else's living room, if you will.

Wow, it sure is windy up here, I have to say!

DJ: [laugh]

HD: When I saw that it was--what are we, two stories?

DJ: Two stories.



HD: Well, anyway, I thought, It's only two flights of stairs I have to drag the teeter totter up, so I didn't really think that it was going to be all that windy. But, wow! [Ed. note: Actually, HD didn't do the dragging. Charles, of A3C, along with another A3C-er made that happen.]

DJ: It's not normally this windy. You are hitting a good day. Because first off, we don't have any sun out, so we lose all our thermal advantage. Secondly, we designed the building literally so that right where you are sitting [laugh] to enhance the wind flowing through during the summer months when it is hotter. So there is actually a Venturi effect, a wind tunnel effect, that has been created by the placement of this building versus the other buildings, which will enhance air flowing through there where people are actually sitting.

HD: When you're talking about the building, you're talking about this new construction [of the UrbEn Retreat] right here?

DJ: Yes.



HD: Okay. Alright, so are there plans to actually put in a wind turbine like right where I'm sitting? Because you could generate a lot of energy on a day like today!

DJ: On a day like today we would be doing pretty good. But even today, we're probably only in the--I would guess maybe 10-15 mile an hour winds. We're able to increase the velocity in this location, but still, the efficiency of the wind turbine, is really best at 20 mph. The curve on their efficiency peaks at about that point and then it tapers off. It's at 20 mph that it's pretty much running at optimal speed. At lower speeds--Oh, thanks Charles! My seedlings, remember! [Ed. note: The wind literally knocks over a stepladder Charles is using to shoot photographs from.]

HD: Now are you just sort of teasing, or are those plants actually sort of fragile?

DJ: They're a little fragile because they've only been in for about a week and a half. And fortunately they are pretty resilient plants. That's the other nice thing. So it's not quite as bad as it could be. Back to answer answer your question ...

HD: ... oh yeah, about the wind.





DJ: We actually originally wanted wind turbines on the front of the building--what they call vertical-axis turbines, they look like a big drill bit for drilling metal. And they would have sat vertically on the front of the building. The reason for that is that Huron [Street] is almost its own wind tunnel. The City Center building and the old Ann Arbor Inn both help, and One North Main, really channel the air down through there.

Because we are in between two historic buildings, the Historic Commission wanted us to study to see whether or not there might be a better spot on our building that wouldn't require it to be on the front. They didn't turn us down, they just simply asked us to go and do a little more research. So we are going to do that.



HD: That's an interesting question, because you know, I live in a historic district neighborhood, and as I start to think about things that I would like to do with my own house--it's not that I'm interested in wrecking the historic aesthetic, it's just that there's things I'd like to do that maybe are not consistent with that historic aesthetic, but are just at the same time energy-efficiency-wise or environmentally a good idea.

So the best place to put a rain barrel for me is right out there in front, because that is the way that the gutters are configured. Now I guess I could reconfigure all the gutters so that they dump all the water into the back and collect it there, but that's just not where the gutters are right now. The downspouts are such that the water is going to run almost directly into the street and into the storm drains, so that is the best place to put rain barrel. But lot of people think the rain barrels are just butt-ugly.



DJ: Well, rain barrels don't have to be above grade. What we have done with some of the other designs is actually bury a storage tank right beside where a downspout comes in, and then from that storage tank actually have a discharge line, an overflow line, that would allow it to run to your storm drain, and essentially the historic aesthetic of your building is not disrupted at all.

And in some ways it actually is better for your storm water, unless your tank is pretty opaque. First off, you're getting rid of any daylight that would add algae. Second you're going to put it in a cooler environment. Part of why geothermal works so well is that when you go down 5 feet into the ground, it's pretty much a constant 50 degrees. So if you bring your tank in, if it's a good-size tank, it's probably three and a half or four feet tall. So half of that tank is there sitting in an environment where it stays very cool, so the water stays cool, stays out of the sunlight. The actual quality of that water is better than it would be if it were sitting up there above ground.

HD: So the quality with respect to the river, as in the river doesn't like warm water?

DJ: It's just not going to like a lot of algae buildup in it. Which is what could happen, just because what happens is the trees will drop stuff on your roof and then that organic material, as the rain hits, that first flush will go down in into your tank and create a build-up in there. So, the less of an environment that you create that enhances the build-up of algae, the better off you are.



HD: So you guys have an automatic way of catching rainwater and reusing it into building? Because what I do involves hauling lots and lots of buckets. So I'll dip into the rain barrel and carry it down to the basement and use it to flush the toilet, for example. Stuff like that. But most people don't have the patience for that, and frankly, I'm running out of patience with it.

DJ: [laugh]

HD: So it's all automatic here?

DJ: Right. Because we are a business, and we've got other things that we need to be about, we wanted the system to run pretty much idiot-proof--that way if we got caught up in some really high-powered projects that need you to get out and it was 80 degrees out and zero humidity ...

HD: ... just to clarify, when you say 'idiotproof', you're not in the way implying that there's a bunch of idiots who work here? [laugh]



DJ: No, no, no. [laugh] Not at all! But we wanted to operate rain or shine or whatever. So the system we've got going in is really a great system, actually a very sophisticated system. It has a moisture sensor, so it won't water when it doesn't need to water. It's designed so that each one of our zones has a different amount of water flow into it based on the amount of area that's involved.

It actually captures the rainwater and channels it through two filter systems, actually three filters, before it goes through the pump, almost like you do a traditional irrigation system. We have a filter that actually takes out any particulates that are very large. We have a charcoal filter that takes out more of the organic material, and then we have a UV filter which actually blasts it to get that last little bit. The system is actually set up so that during most times, the pond behind us will actually be full, whereas at this point we are just getting the system up and running. That's a 300 gallon storage tank.

That zone is actually has two functions. What can happen is it can run as a separate zone. The misters will take the water that's in the tanks running through the system, blow it up in the air, capture it in the pond and the pond actually overflows and runs through our rocks--so essentially we are filtering it through our rock system, through the pond and the rest. An extra benefit is, the windows on the north side of the building are low and right next to the pond, and the windows on the south are high and large, so we can actually increase that Venturi effect through that space, capture a little bit of that moisture in the air as it comes through, and enhance the cooling effect for the [UrbEn] Retreat. That can be done without the need of our mechanical system.

And then when it's in the other mode, in which we've drained our tanks down below that are in the building, we can actually shut it off as a zone to be run for irrigation. It actually becomes a separate feeding tank for our irrigation system. So almost one-third of our irrigation system waters right out of the pond.



HD: So is this expertise--all these systems that you have described--is this expertise that you guys have in-house? Or do you have to, say, go to the--I don't know--the rain collection experts, or the green roof experts, or the geothermal experts, ...?

DJ: We have the ability now to design the systems, but just like when we build a building, while we know the structure and how the grid wants to lay out, we will often bring in a structural engineer to size those things. We would not begin to try and size the piping we need for the irrigation going through it, or necessarily calling out the specific zone valve. But as a general idea of how it lays out, and how it interfaces with the building and the rest, and our coordination of other consultants that have to tie into it, that is the expertise that we bring to the equation.



HD: So I noticed that there is a big poster inside the UrbEn Retreat as a big thank-you to all the people that helped on the green roof. I assume that's this green roof, right?

DJ: That's the green roof here.

HD: The thing that caught my eye, that struck me is just weird and implausible was Firestone??

DJ: [laugh] You mean, were they bringing their tires or their race cars up here?? [laugh]

HD: Yeah, what was their role?

DJ: Firestone is actually one of the largest membrane roofing companies. They along with Carlisle Roof, they probably have the largest market share. There are others, and there's some that are local in our area, and I'm missing a bunch of other ones, but Firestone is a dominant player in the membrane roofing area.

HD: Because just reflexively--this is totally prejudiced and unfair--but when I think of Firestone I don't think of an environmentally friendly active company at all. So that's why I thought, Wow, what's their logo doing on a green roof poster?!



DJ: [laugh] Actually, we were really happy with them. They are not one of the early innovators, but a later adopter into this. But they come at it in a very methodical way. Some of the early adopters had some green roof systems that, quite frankly, I don't think worked nearly as well.

What Firestone has done is teamed up with a group called LiveRoof, and created a tray system that is actually very effective, and the tray system was designed by horticulturists. So the way that it's watered, and the kind of material that is in there, actually works very, very well. They also work with a company called Permaloc that has created a good system for the edge material for the roofing. So they brought together the best of the best in those areas to create their green roof. So that's why we liked it. We saw an opportunity for a green roof system with what they call a wraparound warranty, that is Firestone is warrantying more than just their membrane. They are warrantying that their system will perform well for our roof, as well as the membrane.

HD: You know, this is plenty to be proud of, but is there anything at all that people might not be as well aware of that you guys are doing, that you want to cover right here on the teeter totter?



DJ: You know there are a couple of other systems that are actually kind of fun. The daylighting effect [from the skylights] is probably one of the things that draws your attention. When we bought our building 11 years ago, AutoCAD was just getting started. We used computers to do our drafting. And the screen technology was pretty poor at that time, and so what we had [at our previous building] was an office space that had windows on three sides of the building, and it was beautiful and lots of light came in. When AutoCAD came into our office, we went from a brightly-lit space to a dark, all the blinds closed, the lights turned down ...

HD: ... just so you could see the screens?

DJ: So you could see the screens. So we said, Gee, we found this building that had one window in the back and no other windows going into any of the rest of the office space. We said, Eureka, we found a great building! ...

HD: ... now wait a second, on the people part of the Triple Bottom Line--I would think, though, that [laugh] ...

DJ: ... [laugh] oh, but those people back then were the ones who were actually closing the blinds, and turning the lights down, because of the glare and the eyestrain and the rest. When we started, everybody was happy because it worked really well. But what they forgot, and what we forgot, is that we all desire sun. This whole importance of light deprivation and the the rest, and screen technology finally got around to where we didn't have a problem with having light in there.

So we have gone from a cave to where we can actually operate most times with--24 out of 33 workstations are in the studio area--and those 24 can all pretty much operate without having to turn a light on! In a building that has no windows in it! Just from the daylighting effect from our sky lights.

HD: So there's what--one, two ...



DJ: There's 12 on this roof. And then those tall skylights are really things called solar chimneys. Solar chimneys actually work in concert with what used to be our only window--we actually went back to enlarge that to what the original size was, and we put two windows in the bottom of it. Those two windows will eventually have a thing on it called an actuator. And the actuator will be coordinated with the louvers that are on the north face of our solar chimneys. And when the temperature is a little warmer than what you are and I are sitting in right now, ...

HD: ... yeah, it's kind of brisk up here, actually, isn't it?

DJ: It is brisk up here.

HD: Are you doing okay?

DJ: I'm fine.

HD: Because I'm in the full sun now, ...

DJ: ... you're getting the solar advantage! I have at least the vest and a lot more body mass! So I'm making up for it that way. [laugh]

HD: [laugh]

DJ: But the windows down there will actually open when the roof is heated. On the back side of the solar chimney, on the north side, it's got a cement board and it's painted black so it absorbs the heat. When we were working on them in March, when there was still snow out, you had to strip down to your T-shirt to be able to be in those spaces, because they collect the heat so effectively. So what happens is you got this large volume of air in the solar chimneys, this sort of canister of hot air, that is sitting up there. And when these things open up, that hot air wants to rush out out of the building, so it goes out the louver.

HD: But it pulls the air ...

DJ: ... it pulls the air through the building from where the only place is open is this window down low, which provides us now with fresh air ventilation for the building. So that's a real neat feature, not having to use our mechanical systems to keep the building with fresh air. And you can actually increase the amount of fresh air, which is actually a benefit to all of us as well.



HD: So, I mean, obviously you don't know the specifics of my house, but if I were to just open up the attic panel--there is I guess, a disagreement in our household about whether that would be a good idea in the summertime. My thought is that the hot air is going to rise, no matter how hot it gets up there, it's not going to have a negative impact inside the house and that it will have the same effect that you just described.

DJ: It would, as long as there is a way to provide enough area for air to escape. Most houses now nowadays have a perimeter--or at some location on it--a way of letting air into the roof. And so what would happen is, if you had a little bit of wind at all and you didn't have the ability to completely evacuate that air to the outside, you would now provide the reverse, which is pressure on the outside--from the air coming up through your vents at the edge of the building--and force the warm air from the attic down into your house. The whole-house fans are a tremendous way to cool the house in the summertime. ...

HD: ... so you need to provide a mechanical way ...

DJ: ... well no, because in the old days what they did is they had a roof hatch over that, and essentially you put it up and two sticks, and that provided that free area that we were talking about. Opened up the windows low, and basically a chimney effect right out of the building. So you actually can do it where you don't have to use energy.

HD: So basically I need to address the issue of evacuating the air.

DJ: And actually, what you want to do is get that temperature of the air in your attic down as much as you can, so that when it starts the day, it dampens the heat load of the building itself. That's kind of why we have ridge and edge vents. We try to keep that hot air from staying stagnant, and get it into the atmosphere.

HD: Well listen, thanks for letting me bring the teeter totter up here.



DJ: My pleasure. There is one more thing I want to mention. Because where I'm sitting here, I'm looking at the deck part of our building. We are working with a group called Urban Wood. They're actually a group that is associated with the EnHouse here in Ann Arbor.

HD: Oh, by Recycle Ann Arbor? You know what, I know about them!

DJ: Is that right!

HD: Yeah, you can go buy the wood at the Recycle Center, right? Because I have gotten this beautiful black walnut stuff that I use to make these little desktop teeter totters out of.

DJ: Excellent!

HD: So Urban Wood is providing the wood for the deck?



DJ: The wood that we have in the [UrbEn] Retreat that's around the edge of the meeting space is actually all from the emerald ash borers. The emerald ash borers assisted us and provided us with an ash floor! [laugh] And was harvested by this group, actually. Lee Ullmann was the millwright on that particular project for us. Here on the deck we are actually creating another demonstration site.

We'll actually end up with four double-row widths. We have Hickory, we have White Oak, we have Northern White Cedar, we also have Black Locust. Black Locust actually should be the best rot resistance, followed by the White Oak, followed by the Cedar, followed by the Hickory.

HD: So you're going to be able to see how it degrades?

DJ: We'll look at that. And every other pair of boards is slightly different, and that's because the first of the pair that is closest to you is not treated. The next one is actually sealed up, and it goes that way across the deck. So what we'll be able to do is not only study the performance of individual boards, but the board that we are treating, did it work better or did its natural state work better? And it will be an experiment that we are doing in conjunction with the Urban Wood group.

HD: So are there like grad students involved with us? This sounds like something that could become like a peer-reviewed journal article or something.





DJ: Well, actually U of M Architecture School is working with us on our green roof here. We wound up with 20 sensors underneath the roof that are actually recording the temperature underneath the green roof.

HD: Really!

DJ: In the front part where Firestone is, we have 10 of the sensors, because the upper northwest corner will actually be coated with four different kinds of coatings. And underneath each one of those there's two sensors--one as a backup--and they will actually track what the temperature is directly underneath the membrane. And that will allow us to be able to see whether or not in southeastern Michigan a white roof, a black roof, gray roof, or a beige roof performs better.

And we actually have three different kinds of green roofs up here. We have our 2 inch, inch-and-a-half essentially, called a mat--it looks like sod--and it rolls right out. We have our trays in here in the middle, which is the LiveRoof working, and that's a 4-inch tray. And then we have our monolithic system--the material comes in big bags and we spread it out just like you would dirt on your lawn. The monolithic goes from 4 inches up to 8 inches.

So we are tracking under the 2-inch, and the 4-inch, the 4-inch monolithic and the 8-inch monolithic, with sensors to tell us how that affects the roof temperature. Initial studies suggest that the green roof--when it's in, and is doing its thing, and it's got the full growth in like our Live Roof roof does now--will capture about 10 degrees of that heat that is going to be down the roof level, which could reduce our air-conditioning load by as much as a third from what it would be otherwise.

HD: So the data that these sensors are collecting, it's not like a continuous stream is it ... ?



DJ: ... it is , as a matter of fact. It's going to get hooked up with a computer, and we are working with a gentleman over in the Architecture School here at the U of M, we will actually hopefully take this data and have research students like you were talking about. Our other goal is to work with the Hands-on Museum and hopefully we will ...

HD: ... that's right across the street from here isn't it?

DJ: Yeah. When our railing system is all in, and our safety measures are all in place, we'll allow tours by middle school students who might then be able to see what's going on here as far as building a sustainable building and what a green roof could actually be like.



HD: Speaking very selfishly here, you mentioned all that data coming in from the sensors and hooking it up to a computer, what would be really cool ...

DJ: ... it will get shared!

HD: Well, I'm sure it will get shared in the scientific community or whatever, but if you had on your website just a real-time read-out and graphs so that people can log on and see what's going on underneath the green room--just for pure entertainment. It wouldn't be like a green roof cam ...

DJ: ... with any luck there will be a green roof cam that will actually watch how the green roof grows over time. Right now, Charles is our green roof cam and he takes photographs of it weekly to give you an idea of what's going on. But eventually what we'll hopefully have instead is a live cam. Our goal is that we would work with Mel Drumm over at the Hands-On museum to be able to provide a feed for them that someone over there can watch our green roof over time and see how it changes. We've got a lot of things in the works. Unfortunately we have to have this architecture practice that keeps taking time from getting all of these things in place! [laugh]

It is great fun, and we're really having a wonderful time, our staff loves the space up here, but it's also been a great opportunity for us to learn a whole lot more about the environmentally-friendly design, too.

HD: Well listen, thanks a lot!

DJ: You're welcome!