Our project is to build a new hotel and add an exhbit hall to an existing convention center and to add more meeting rooms and ballrooms.
Based on previous CIRs we are ruling out the hotel guests from the Bike rack calcs.
The total users of the meeting spaces during peak (which I assume is the code maximum at all the meeting spaces without taking any diversities for double count of the occupant) is 8,484 people. Say we have 200 FTE staff at both the hotel and the meeting spaces, then our total building user count for the bike rack calc is 8,684 people. This would require 433 bike racks at 5%. 433 bike racks seems excessive. How do we take into account that most of the meeting space users will be the hotel guests?
In general, how do heavy transient user projects like convention centers treat the bike rack calculations?
Mara Baum
Partner, Architecture & SustainabilityDIALOG
674 thumbs up
March 2, 2010 - 8:49 pm
Good question. I can take a guess at the answer, but am not certain of the best approach. In general, projects with high transient populations are actually required to install the number of bike racks required by the credit. While 433 bike racks sounds like a lot, so does 8,484 people. You might try to determine whether or not your client will rent the meeting spaces based on code maximum occupancies, or other criteria. If it's the latter, your transient count will drop.
A CIR ruling dated 9/14/2006 implies that the convention center visitors need to be included in the bike rack calcs -- "It is not acceptable to automatically exclude all transient visitors from these calculations as it is reasonable to expect that some of the visitors to the retail shops, conference center, theater, and gaming facilities could potentially arrive on a bicycle..."
Although it's likely that some of the convention center visitors are staying in the hotel, there's probably not a way to directly prove or link this. You could try a CIR that asks to deduct number of hotel rooms from the convention center visitor count, but since it's possible that 100% of the guests could be coming from outside of the hotel, I'm not sure this would fly. Even convention facilities that most often accommodate out of town guests usually also hold events geared toward locals.
There are several LEED certified convention centers -- you might look and see if any of those got the bike rack credit, and if yes, how they did the calculations. You can probably search for this on the USGBC website, on BuildingGreen's case study pages, or on Google.
PREMNATH SUNDHARAM
Chief Climate OfficerDLR Group
20 thumbs up
March 3, 2010 - 12:45 pm
Hello Mara,
Thanks for your response. I understand that a facility which could anticipate 8,000 people could potentially anticipate 400 bike rack users.
Rather than try to tackle it from reducing the number of bike racks required, I wanted to approach it from the intent of the credit. The intent of the credit is to encourage people to use bikes and promote for a behavioral change in the way they commute.
So, I first wanted to understand how often the existing bike racks in the existing facility gets used and then find a way to promote behavioral change by way of introducing more bike rack options to the user.
The existing bike rack count is based on local code that requires total bike racks at 5% of max parking capacity. I spoke with the convention center facility manager and found out that the existing bike racks are primarily used for Traffic Control. It appears that, say if the convention center exhibit hall is rented for an event that attracts local community, then the renter of the exhibit hall would also rent the bike racks to allow for their representatives to traffic control / police the people at the parking lot and so on. The actual number of users that really use the bike racks to attend events seems to be very low.
So, on an average, the facility manager believes that it would be fair to say only 10% of the convention center attendees for local events might actually use the bike racks available to attend the event.
So my approach to achieve this credit intent is to provide more bike racks than the current usage anticipating a future growth and change in behavioral pattern.
Applying Current usage rate to new construction portion:
Hotel Guests, Retail Customers, Visitors, Employees are the four types of users at this facility.
Based on the proforma for the hotel, we know that the expected occupancy is 70%. So we have 787 guests at 70% = 551 guests. Based on a CIR dated 9/14/2006, hotel guests can be eliminated from the bike rack calcs if they are believed to be primarily from out of town. In our case, they are and hence I eliminated hotel guests from the below calcs.
Retail customers (Bar / lounge / restaurant / hotel lobby) per code is 328. Assuming that most of the retail customers will be the hotel guests, I am taking only 50% of the code max on Bar/lounge and Restaurant and 25% of the code max on Lobby for non-hotel transient visitors. So the new total for non-hotel retail customers is 148.
I got the actual maximum seating capacity for all the meeting rooms and ballrooms at the hotel and the convention center. The seating capacity chart for some rooms share the exact code occupancy but some are lower than code. Total visitors per seating capacity = 6195. Even though some of the convention center visitors could be the hotel guests, as you pointed out, it could entirely be local people, so I am not reducing visitor count for hotel guests.
Total employees at both hotel and convention center (at peak) is 145
Total transient visitors = Retail Customers (148) + Visitors (6,195) + Employees (145) = 6,488 (Excluding Hotel Guests)
Applying the current usage pattern of only 10% of the people anticipated to use bike racks, the number of people expected to use bike racks based on current behavioral pattern is 6,488 x 0.1 = 649. Required bike racks to meet current usage pattern = 5% of expected people using bike racks = 649 x 0.05 = 33 bike racks.
Approach ONE to promote behavioral change:
Simply double the number of bike racks required to meet current usage pattern to allow for more usage and eventually change the behavioral pattern. So provide 66 bike racks.
Approach TWO to promote behavioral change:
1. Convert the retail customers and visitors to FTEs based on the amount of time per day and number of events in a year they are anticipated to attend at the convention center
2. Provide bike racks for the new transient users’ total
I found out that the convention center meeting rooms are expected to have 60 events per year. At two days per event on an average, the expected number of days the meeting rooms are anticipated to be used is 120 days. At four hours a day maximum on average per visitor, the FTE count for Visitors comes to 1430 ((6195 x (4/8)x 120) / (52x8x5) = 1430)
Assuming the retail spaces would see the same usage rate as the hotel guest rooms, the actual number of days in a year that the retail spaces would be see peak users is 70% of 365 = 250 days. At 3 hours per day per retail customer at the Bar and Restaurant and 1 hour per day per customer at the lobby, the FTE count for the Retail customers comes to 50.
Do the same FTE count for the employees over a year, the actual FTE count for employees comes to 165 (Assuming full time employees at 8 hours and half time at 4 hours)
So, the new total transient user = FTE Retail Customers (50) + FTE Visitors (1430) + FTE Employees (165) = 1,645
Providing bike racks at 5% for this new total brings the required bike rack count to 1,645 x 0.05 = 84.
Conclusion:
Approach TWO provides more bike racks than Approach ONE. Either of the two approaches provide more than double bike racks than the current usage rate. As the usage rate increases over the years, I may be able to get the convention center to agree to provide a valet bike parking during high demands on offsite locations.
We are planning to provide 84 bike racks on our design. At a minimum promoting the employees to use bike racks would begin to address the behavioral change. So we strategically located bike racks near the employee entrance and close to the Light Rail stop. We are providing double the required bike racks for the employees to promote more employees to use bikes. (Required 9, provided 20). The rest of the bike racks are geared towards the convention center visitors and are located near the bus stops. Through this approach we are gradually promoting the behavioral change rather than invest the entire infrastructure for bike racks today.
I apologize for the long response. Does this logic make sense?
Also, we have been exploring at how other convention centers achieved this credit (most of the LEED certified ones have achieved this credit). Will keep the forum posted.
Any thoughts will be greatly appreciated.
Thanks.
Prem
Mara Baum
Partner, Architecture & SustainabilityDIALOG
674 thumbs up
March 3, 2010 - 9:54 pm
There's a lot here - I hope I can break my responses down in a way that make sense. There seem to be two questions: one is how to calc the occupant load as appropriate for this credit, and two, how to use that number to determine the number of bike racks needed.
For the first question, I would ask, is the bar/lounge/restaurant/retail all within the hotel itself, not the convention center? If not, then I don't think you can take a 50% reduction in the transient population count. If so, then maybe -- but I'm not sure. As for the lobby, I would suggest that everyone there is just passing through on their way to other destinations, so I wouldn't count them at all. If this is one of those great hotel lobbies that is really a destination in its own right, then I would count the number of seats (couches, chairs, etc.) and use that as the transient occupant load... plus, of course, FTEs who would be working there.
In your second approach, I don't think that converting visitors to FTE equivalents is appropriate here, because we're looking at a peak load condition. Also, I don't think I'd assume that the retail spaces would have the same occupancy as the hotel. If there's a big convention, then these spaces will be in full use (the hotel will probably be full) -- and this is the condition we're most interested in, since we're looking for a peak (not average) transient occupancy.
The second question is relatively straight forward -- you just take the occupancy number and multiply it by 0.05.
In your first approach, you say, "Applying the current usage pattern of only 10% of the people anticipated to use bike racks, the number of people expected to use bike racks based on current behavioral pattern is 6,488 x 0.1 = 649." This is the type of calc you would use for LEED (with whatever occupancy load you end up with), although the LEED requirement is for 5% not 10%. However, I really don't understand this next step: "Required bike racks to meet current usage pattern = 5% of expected people using bike racks = 649 x 0.05 = 33 bike racks." This calculation is not a part of LEED. Also, the current usage rate is not relevant for LEED calculations.
As for your approaches to behavioral change, anything you do is of course great, but this is not directly related to LEED. The exemplary performance option for this credit involves a comprehensive transportation management plan, not adding more bike racks. If we look beyond LEED for a moment to discuss behavioral change, I would suggest things like providing free maps of local bike routes, bike-buddy programs, and connections to safe (often smaller) streets and local bike routes, possibly working with the local transportation department if necessary. Also, providing bike racks in places that are covered or perceived to be safer (e.g. next to a guard station) can also go a long way. I am a big fan of bike locker rentals for regular bike commuters.
In summary, you need to multiply your total FTEs + total peak transients by 0.05 to get the total number of bike racks needed. Note that my comments with regard to occupancy counts are just my best guess; GBCI has the final say on these matters.
There may be other, better intelligence out there on this issue, so if you find out how other convention centers have achieved this point, definitely share that with us in this forum -- thanks.
Jean Marais
b.i.g. Bechtold DesignBuilder Expert832 thumbs up
March 4, 2010 - 12:34 am
Well done Premnath, you've successfully pointed out what a nightmare this calculation is for all high transient buildings.
I understand that 10% usage was what your research and questions to the facility manager came to...
Mara has a point that converting peak users to FTE, i.e. spreading their occupation over the space of a 8 hour day is tactically not appropriate. I personally hate it when all the bike racks are full at peak times.
However, I would like to also say that often these big convention centers are located outside of town or on city limits accessable only by a train link or by car. Out on the motor way there are no bike paths and biking to these centers is out of the question from a safety point of view.
Some city center centers are otherwise quite accessable by bike for the local attendants. What percentage of convention center attendants is local also depends on the type of convention. The convention type will change for every convention and their may be hundreds in a year.
A one size fits all solution here seems unlikely to come out. For starters the USGBC and LEED should give more tips here. What fits for an office can't always be made to fit everywhere.
In your case I would find a number for the peak local users and add the FTE employee count to it as the sum to which to multiply 0.05.
PREMNATH SUNDHARAM
Chief Climate OfficerDLR Group
20 thumbs up
March 4, 2010 - 11:36 am
Mara and Jean,
Thank you for your responses. I agree with Mara on the appropriateness of converting transient users into FTEs. My thought was, converting to FTEs could be one way to dilute the load down to just local users.
I got this idea of converting from a colleague who has successfully achieved this credit with GBCI through this approach on a Baseball Stadium which has similar occupancy type and rate of use.
Also, I toured another convetion center locally in town that has achieved this same credit. The size of this convention center is three times the size of our new addition and they have only 46 bike racks for the entire facility sprinklered around the facility and in the garage, which tells me that they probably provided bike racks just for the employees.
Also, googling on green convention centers, the following link highlights a few that has provided bike racks.
http://www.gcbl.org/planning/convention-center/green-convention-centers-...
Notice on the above link, Jackson Center is only providing bike racks for employees. So providing just for the employees seems to be the trend here.
Anyone who has any knowledge on these projects, please share your thoughts.
I will try to get some statistics on local users for the convention center and try to meet the required bike racks for at least the local PEAK users.
Thanks again for your time and thoughts.
Prem
Mara Baum
Partner, Architecture & SustainabilityDIALOG
674 thumbs up
March 4, 2010 - 12:12 pm
One final comment - not all credits are appropriate for all projects; it's just the nature of the LEED system. In an extreme case, for example, I would never recommend pursuing this credit for a convention center in the middle of nowhere with just highway access.
This calculation is definitely difficult for any building with a high transient population -- stores, libraries, hospitals, community centers, etc. -- and you often have to make some assumptions about numbers. The important thing is to be able to back them up with sound logic, and when in doubt be as conservative as possible.