opaque. if we rendered that in metal this is what it would look like and that pattern has an underlying grid lock pane to it. if it were a trapezoidal shape or non-angle corner. it would look sloppy at the edges. that presented an opportunity for us that we'll get to in just a minute. there are various patterns. this is a snowflake pattern that are interesting mathematically derived crystal lion like forms and they are in grid like structures called periodic structures. our panels are not really right angled panels. they are trapezoidal shape so it caused us to look beyond

grid like patterns. after a bit of research we found other scientific relationships. this is an electron microscope photograph of the atomic structure of an aluminum alloy, very similar to the aluminum alloy that we are proposed for the building itself. it's also a very good example of what's called a quasi crystal or non-periodic pattern. even those there is elements that repeat, there is no grid structure to it. it's one of the ideas behind the 2011, to understand what a quasi crystal non-periodic pattern in nature. from england it came

from a similar idea called the pen rows panel. it repeats in a fashion. since it's not periodic, it's not grid like. it can be tut cut at the edges without any resulting -- sargs. when it's cut at a non-right angle, the edges become rather frayed. you can see the pen rows panel adapts quite readily to the edges of the building. we started becoming very interested in the idea of the

kind of crosscurrent of science, engineeringnd architecture and art that all come together that looks at patterning quite well. it looks an is a narrative to key into the bay area. all of the areas have similar underlying values and if that narrative is built into building it could become quite powerful. it's also a series of dots and there is a great range in how one might render the building to start to the developed. let me pass down the materials and colors we are looking at. so the first piece that you see here is clear anodized aluminum in the pen rows pattern. that

is an 18 inch square. the panel itself is roughly the size of two of those boards. so that panel is '116 of the whole panel exterior wall. there are no curves in these panels but the way the panels are motion to dismiss motion -- the panel will be '3'18 inch square. the panel itself is roughly the size of two of those boards. so that panel is '116 of the whole panel exterior wall. there are no curves in these panels but the way the panels are -- the panel will be '316 of an inch thick. it will be a very controllable surface, very beautiful surface. what is interesting about this idea is that there are a number of metal panel buildings in san francisco. one of the ones that has aged the best is macky art

center. the sidewall of that the building is also clear anodized aluminum. it looks as handsome as the day it was first finished. we believe it's a good choice. it's also possible to be painted. it has a white finish. it possible we might use the same white as the finish for the new metal exterior wall. this is a choice we can make later. if you look at it carefully at the sample being passed around, there is a metal flake quality to it that creates a very light surface. you'll another option which is another form of paint which has

an ir -- it might be related to the tower but different, a very lively exterior wall. we have to look at it carefully on-site. the third option is stainless steel. it's out of our cost parameters. we can entertain it to ask whether it could be steel. it may look very handsome like if we look at the disney concert hall in a los angeles, those are gastrointestinal steel

structures. frank gary's famous buildings. those are options. i will go to close-ups to show how the wall might seem in detail. although the the building is curved, it's made up of flat panels that are facetted curved shaepd shapes. the lowest the building gets to the ground is the molding as the wall turns to the ceiling. one of those panels is 16 of those small samples you just sent. although that pen rows apparently panel that you see here is appropriate. so this is that same view, but

rendered in the pen rows pattern. this is with lines rather than dots. you can see that instantly that it's a very beautiful wall. but we think equally handsome. this is again why we brought the large gloss because it's hard to appreciate on the screen, delicacy and unique pattern. it's slightly more dense, this is a bit more metal in this version than there is open but it's also quite beautiful. once again that's what you see in this panel. one question is what would this be like inside. one shows the previous glass version and bear in mind that

previous forms, the wall was 60 percent transparent versus 40 percent in the pen rows pattern is the issue being looked at here. this is interior view when the the building is wrapped in the per forted metal skin. it's what one finds in a theatrical stage, it's a very beautiful kind of warm presence and a very unique place to be inside of, particularly the bus deck which is where this view is taken from. we also saw other opportunities in the change from glass to metal that come about because once again this is a less transparent wall, this is like a theatrical

set which creates drama in the evening and lighting in the building. the last two images here shows two ideas. one idea on the left is to light that massive super structure that you see running 5 blocks from one end to the other. if just those 2 big columns are lit from the street to the park with a beautiful presence also an led light source which might be used for special occasions. it might be programmed and be used to celebrate anything from holidays to winning the world series again which is bound to happen. so we think the

building itself then becomes a very lively presence in the city. and i believe that's everything that we have. >> great, are there any questions from directors? >> director reiskin. yes. i would like to comment you and the team to what seems a lot of stop has come to this and 2 challenges which is the vulnerability of the initial design and the cost. it's great. i have a number of small questions. the first is the increased opacity. what does that do to the demands for interior art, interior lighting and the energy use of the building and lead issues? >> well, we are study that

right now. we are trying not to have increased usage of artificial light inside the building. we have a number of light sources including a natural light tube that brings like from the park level that is still there even with the metal scan. but to be obvious it's a technical question we are looking at now. the opacity is flexible. we may wind up with 50/50 percent proliferation. >> in terms of -- this is -- would be more open air than the glass configuration? >> it's a per fraetd skin. in

both cases the skin is hanging out from the transcenter from about 20 feet away. in both cases air flowed behind but in the metal scan the air will also flow through the skin. in many ways that's a better blast response than the glass was. from a ventilation and safety point of view it's probably a better choice. >> okay. and then, i guess a little bit related. so that means rain and other exterior elements will get to the gaps. you referenced external variability for the aluminum but for all the difference options what kind of maintenance and visual longevity applications?

>> the issues depend on the surface that we ultimately choose. with anodized aluminum which is the large sample you see there, that's probably one of the most durable surfaces that one can build. i would urge to you go boo i the art center to see how it's aged. that's a surface very maintain able. if we were to use a paint, it's an epoxy paint, very well used in the market. if you see a paint, epoxy paint was used to achieve that color. we know that's also very durable. if we use stainless steel, it's an interesting material. it not actually stainless. stainless steel is one of the most sensitive

materials are used. we have to be careful about the finish coat and polish to deal with stainless. that's part of the research that's being done now. >> on the patterns, i didn't understand the difference between the problems, it seems like they would have that a little bit and the other question whatever pattern you would choose would you try to create adjacent? >> that's really the issue with the choice of pattern. if the pattern is based on a grid, for instance a simple dot grid, as you cut it, there is the issue of cutting against the grid cutting in an odd way that kind of works against the notion of a gridded surface. when two of those panels are side by side, that disjunction is visible.

there could be some very uncomfortable relationships. with the pen rows panel it accommodates that disjunction. you are not looking for the gridded structure because there is none. it helps solve that problem because your eye is not tuned to looking for those relationships. it's really why we looked at the pen rows patterns. >> thank you. the last point, the nodes of led lights made me think of the bay lights project, i see part partnership for those. >> i have to admit i was very taken boo by the theoretical

-- i think it's a major decision that we are having to make here. looking at the patterns, these are the metal plates are not being stamped, they are being cut? >> they are laser cut and very simply cut and pressed. >> and one of the things that i don't quite understand is the differential just the slight differential, the 1 '8 different of stainless versus aluminum because one might think stainless steel is much more resistant, much less vulnerable than aluminum. why do you get such a small

differential? >> some of it has to do with cost and if we use a stainless that is within our cost parameters. it maybe an increase that we have to resolve. stainless is more stable, as a material, it's a denser material so we can use a lighter thinner gauge of stainless than we need to do with aluminum. aluminum is a more malleable particularly as it's being assembled. that's why the plate makes a big difference in aluminum because it's softer. >> so, and does some of the differential or the lack of the differential comes from a fixed plate? >> they need to be very flat. it's by and large extremely

flat material. and if any distortion in the surface whether glass or metal at this scale of a building it's going to shown up assistantly instantly and that will be obvious. >> some years ago i was involved in a process in chicago the cloud gate and the contract for the sculpture in the park. it was constructed locally. what amazed me was this machine that is also -- it took any place of metal even 3 '16 stainless and with the mathematical formula programmed into the computer would come out in both dimensions in an

exact curvature that enabled the vision of having a perfect mirrored surface, 30 feet wide, a perfect mirrored object realizable. so, i'm wondering whether or not if you look at some -- what you would need a very minor degree of curvature of cloud gate which is very complex in formulaic but it would seem if that would enable you to go down to a smaller -- i did some pricing on the differential and the difference between 20 gauge stainless steel and 16th aluminum because i didn't know what your factors were, it's about the assessment

you can get stainless steel down to a price or even below what aluminum would be and if by putting in some curvature at the same time you can turn this surface into something more consistent and with the mirrored surface at the same time restore some of the either realness. i would like to see that the notion of putting some curvature in enables differential between stainless and aluminum to a point where it would be considered. i think it could be just a remarkably beautiful beautiful building done in mirrored stainless in the same pattern. >> i agree with you and i'm going to oakland and meet that

person and make that part of our research. absolutely. >> any other further comments or questions. i'm curious about the maintenance cost of keeping the panels clean and also if there is damage to it from whatever natural weather controls there might be what the cost differential would be in the long-term between the aluminum metal or the glass? >> i think the metal frankly is going to be easier and less costly to maintain honestly. however there was always a maintenance program in the glass version and also line items in the budget for the operation of the transit center in general for the maintenance of the exterior wall. it's going to be easier to take care

of. in terms of replacement, the panels on the corners can be taken down quite easily, in many ways less delicate than the glass. in all this is a more sensible fwolg building to take care of in the long run. this is on people's minds, san francisco is lucky to have an example of dozens of buildings with metal -- we can see how they have been taken care of and aged. we are in the middle of that now. i think we are going to do the best version of this wall that one has seen in town. >> thank you very much, i have to agree. it's nice to see that a direction that we've taken in some ways both for safety and for cost reduction is actually something that is working out

in a very lovely way and perhaps a stronger design for the building. so it's nice that the 3 kind of objectives are nicely together. >> bringing what we have together so far. the design team is constructing the project and they have it deliverable to us on may 31st of this year on the over all transit of the center. as well as the glazing system package which includes not only the w 1 system but the specialty sky lights, glass floors and other systems in the package. we had

originally issued that package for -- bid and suspended that process for the an allowing of the design of the w 1 system and we'll be actually folding in the remainder of the storefront glazing to increase the overall glazing component of the package, but to resume the bidding schedule on that, we need to issue an addendum in june of this year to keep that process on schedule as part of the overall construction package and that's where we are seeking guidance on this change. the opportunity to reduce cost in the glazing package is a significant one. when we have completed the bidding of the first 5 major packages which include the skavgs, substructure, super structure, glazing and ceilings, we have locked in

about 2 thirds of the value of the construction center. within those early packages, this system because of it's area, because of it's magnitude, presents a present unique opportunity for to us reduce construction cost in a significant way and that's where we are bringing forward this recommendation. >> and bob, just to clarify, you are saying that we are looking at a saving of up to $17.5 million. >> $17. million is what we are working with. in addition we are looking to discuss the rba guidance area and design team to incorporate

those changes for the packages prepared for may of this year. again, we have reviewed, the staff has reviewed the design guidance criteria with dvs securities and sme, the architect, the program management team to identify the most cost-effective and practical means of fulfilling objectives and the guidance criteria. where feasible we have planned for the addressing of the design guidance criteria in phase 2 and we've developed estimates of the cost for addressed the design guidance criteria in phase one of the transit center construction. to ensure the incorporation of those design of guidance criteria, we are seeking an authorization from the board to

direct to incorporate those changes into design. and we will be as i mentioned, evaluating the steel bid and coming back to the board with an over all on the budget phase 1 and looking for additional revenue strategies. we are planning our revenue strategies on other funding opportunities to meet revised budget. it's important to recognize that in directing the design team to incorporate the design guidance criteria were not authorizing the construction of those changes or modifying the budget but the board would need to take action on a revising

phase 1 budget before we reward packages that are incorporating those changes and we expect to bring a revised budget to you after further briefing the board. few words on the revenue picture. as we mentioned in prior meetings we have identified 25.$25.million. those come primarily from the projected increase in land sale values but also from transit center district plan revenues and reflect $18.2 million in funds that were originally estimated for phase 1 budget