ISSUE:  Petitioner seeks a Relief from the provisions of Chapter 13 of the Florida Building Code, Building for part of a building under the provisions of Section 13-101.1.5, Limited or Special Use Buildings.

 

Mr. Heath Baxa of M-E Engineers, Inc, is designing a ballpark for the Florida Marlins. The project is described as follows:

The project consists of a 928,000 square foot, 37,000 spectator Major League Baseball complex, enclosed within a three panel operable roof system which covers the playing field and seating terraces. In the open ballpark configuration, the operable roof panels park over a plaza adjacent to the ballpark and the outfield walls are retracted. For the majority of the year, the ballpark will be open to the sky to allow the natural turf to grow. For an anticipated 60 ballgames per year, or for less than 5% of the year, the roof will be closed and the interior will be cooled. Portions of the bottom two levels of the ballpark, the field level and mezzanine level, are used year-round by the team and support staff and are considered regularly occupied. These areas represent less than 200,000 square feet, or approximately 20% of the total ballpark. The levels above, including the main concourse, suite and club levels, press and upper concourse levels are only used during events. The number of anticipated events per year is 83.  The architecture of the ballpark is a kinetic and sculptural expression with large curvilinear moveable roof panels, and exterior form. The exterior skin of the ballpark consists of a faceted metal panel system, bands of glass curtain wall and plaster. [Images provided]

 

In his amendment dated March 19, 2010, Petitioner makes the following request: 

 

It is requested that a Declaratory Judgment be issued granting the Ballpark Special Use status as allowed by Section 13-101.1.5 of the Florida Building Code, and the Code Compliance Requirement for 15% energy cost savings be adjusted. Adjustments to the Code Compliance Requirement of 15% energy cost savings would be calculated using a hybrid method for calculating the Ballpark’s energy usage as follows:

1. Use Method A, the Whole Building Performance Method to demonstrate the energy cost savings for the regularly occupied spaces of the ballpark only. These calculations will be completed using the State mandated EnergyGauge Summit program, and the compliance printout shall be acceptable compliance documentation (showing compliance with the Code Required 15% energy cost savings).

2. Use Method A, the Whole Building Performance Method for the entire Ballpark to calculate the project’s total energy cost savings using the eQUEST energy simulation program. The project shall demonstrate 12% or better energy cost savings relative to ASHRAE Standard 90.1-2004 Appendix G (a 20% reduction in the energy savings goal based on the proposed Special Use designation). The energy analysis report to be submitted will be consistent with the format accepted by the USGBC to demonstrate LEED compliance with credit EAc.1 Optimize Energy Performance.

 

Using the Special Use designation requested above, the ballpark shall be considered compliant so long as the following, as used by the Florida Building Code, is met:

Annual Whole Building Energy Cost Savings = 12%

 

 Background: 

1.       Section 13-101.1.5 of the code, Limited or special use buildings, reads as follows:  “Buildings determined by the Florida Building Commission to have a limited energy use potential based on size, configuration or time occupied, or to have a special use requirement shall be considered limited or special use buildings and shall comply with the code by Method B of Subchapter 13-4. Code compliance requirements shall be adjusted by the Commission to handle such cases when warranted.”

2.       Section 13-400.0.B of the code, Method B, the Building prescriptive method, reads as follows:  “This is a prescriptive methodology that is allowed for shell building, renovations change of occupancy, limited or special use buildings, and building system changeouts. The building envelope complies with the standard if the proposed building meets or exceeds the Mandatory Requirements and all relevant criteria on Form 400B or the Energy Summit Fla/Com 2008 computer printout. Only the prescriptive envelope measures of Method B are permitted for shell buildings.”

3.       Petitioner described 8 limitations to the EnergyGauge Summit Fla/Com computer program used to calculate compliance with Method A, the Whole Building Performance Method, that would prevent it from adequately modeling this building.

a. The ballpark has a retractable roof, with the large bowl volume cooled as a single zone. This zone is approximately 400,000 square feet floor area and 250 feet high. It consists of a very complex geometry with numerous bands of windows, curved walls, and a complex roof. The EnergyGauge Summit program limits zone area to 100,000 square feet and zone height to 50 feet. It would not be practical or realistic to break up the volume into the required 20 zones.

b. The ballpark bowl has 1250 kW of sports lighting for the zone. The program does not allow input of more than 199 kW per zone.

c. The locker room air handling units located in the year-round occupied field level utilize enthalpy recovery wheels, which are a key energy saving strategy for the project. The program does not allow input of an enthalpy wheel.

d. The program does not appear to allow modeling of the retractable nature of the roof. Most of the time the roof is open and the bowl is unconditioned. During some games, the roof is closed and the bowl is conditioned. When the roof is opened, the walls separating the interior sub-volumes from the bowl are exterior, but it does not appear that the program is able to take this into account.

e. The geometry of the building is very complex. The program does not have a graphical type of input, so it is impossible to see how the program is constructing the model. The building contains very large walls with bands of windows.

f. The program does not allow control of the exact placement of windows within each wall, so shading effects of building overhangs are not accurately modeled.

g. The whole building simulation method allows for energy savings by self-shading. Due to the geometry of the project, self-shading and orientation provide energy savings. The EnergyGauge Summit program takes self-shading into account.

h. The project schedule of occupancy is much different than a typical office building schedule. The majority of the building is not in use through much of the year. The EnergyGauge Summit program assumes a typical year-round schedule for the whole building, which produces inaccurate energy savings results when considering that the proposed design focuses energy savings on the regularly occupied spaces and not the event use spaces..

4.       The EnergyGauge support office volunteered to perform the work needed to expand the zones required to model this building. Proponent has said that such an effort would not adequately model the building and would unduly delay the permitting process. EnergyGauge support staff did concur that the program could not model all facets of this building.

5.       Petitioner is correct that the building is unusual and as described has a limited/special energy use potential. Petitioner estimates that the dome will only be closed about 83 times a year.

6.       Section 13-400.0.A, the Whole Building Performance Method, “is a computer-based energy code budget method which may be used for determining the compliance of all proposed designs, except designs with no mechanical system. Under this method, cost performance is calculated for the entire building based on the envelope and major energy-consuming systems specified in the design and simultaneously for a baseline building of the same configuration, but with baseline systems. Compliance is met if the design energy cost does not exceed the energy cost budget when calculated in accordance with this section; and the energy efficiency level of components specified in the building design meet or exceed the efficiency levels used to calculate the design energy cost. Compliance calculations are those utilized in the EnergyGauge Summit-Fla/Com computer program and are as described in Appendix 13-B. Basic prescriptive requirements described in the sections called Mandatory Requirements shall also be met.”  The Method A energy cost budget is based on criteria in Chapter 11 of ASHRAE Standard 90.1-2004, with a 0.85 multiplier applied to the calculation to make the code 15 percent more stringent than ASHRAE 90.1-2004, not to Appendix G of ASHRAE 90.1-2004, which is a building performance rating method. Standard 90.1-04 specifically states that Appendix G does not offer an alternative compliance path for minimum standard compliance.

7.       Conceptually, a building designed to be compliant with Method A of the code using the EnergyGauge Summit computer program could be used as a baseline building by another computer program to establish an energy cost budget. If energy costs for the actual building being evaluated can be determined to come in under the energy cost budget established for the baseline building, equivalence to a compliant building could be determined. 

 

Staff Recommendations:  Based on the above facts and circumstances, staff provides the following recommendations as answers to proponent’s request:

To the petitioner’s request, that the Florida Marlins Ballpark in Miami, Florida, be granted Special Use status as allowed by Section 13-101.1.5 of the Florida Building Code, Building, and that an adjustment of the code’s 15% energy code savings be calculated using a hybrid method for calculating the Ballpark’s energy usage [as shown below], the answer is

 

Option 1: that the Commission allow determination of code compliance by Petitioner’s proposed methodology.

 

Option 2: that the Commission allow determination of code compliance by Petitioner’s proposed methodology if the Annual Whole Building Energy Cost Savings is changed to 15 percent and Chapter 11 of ASHRAE 90.1-2004 is utilized instead of Appendix G.

 

Petitioner’s Proposed Methodology:

1. Use Method A, the Whole Building Performance Method to demonstrate the energy cost savings for the regularly occupied spaces of the ballpark only. These calculations will be completed using the State mandated EnergyGauge Summit program, and the compliance printout shall be acceptable compliance documentation (showing compliance with the Code Required 15% energy cost savings).

2. Use Method A, the Whole Building Performance Method for the entire Ballpark to calculate the project’s total energy cost savings using the eQUEST energy simulation program. The project shall demonstrate 12% or better energy cost savings relative to ASHRAE Standard 90.1-2004 Appendix G (a 20% reduction in the energy savings goal based on the proposed Special Use designation). The energy analysis report to be submitted will be consistent with the format accepted by the USGBC to demonstrate LEED compliance with credit EAc.1 Optimize Energy Performance.

 

Using the Special Use designation requested above, the ballpark shall be considered compliant so long as the following, as used by the Florida Building Code, is met:

Annual Whole Building Energy Cost Savings = 12%