BACKGROUND
On January 17, 2017, the Mayor’s Blue Ribbon Panel on Sea Level Rise discussed the attached Ordinance amendment and recommended that the City Commission refer it to the Land Use and Development Committee and Planning Board.
On February 8, 2017, the City Commission referred the proposed Ordinance amendment to the Land Use and Development Committee (Item C4 D). The amendment was simultaneously referred to the Planning Board. Commissioners John Elizabeth Alemán and Joy Malakoff are the sponsors of the item.
On February 15, 2017, the Land Use and Development Committee discussed the item and continued it to the March 8, 2017 meeting. On March 8, 2017, the Land Use and Development Committee recommended that the ordinance be transmitted to the Planning Board with revised language clarifying that additional height is specific to the first level.
PLANNING ANALYSIS
In an effort to adapt to the effects of climate change and sea level rise, the City has adopted regulations related to the Base Flood Elevation (BFE) and Freeboard to encourage the ground floor of new buildings to be developed at a higher elevation. In addition, the City is raising the levels of roads and sidewalks to ensure that they remain dry and passable. During this transition period, sidewalk and ground floors may be located at different elevations. Commercial buildings, however, rely on customers passing by the sidewalk and being drawn in by the view of the commercial uses inside.
As a result, the attached ordinance amendment would allow for buildings in commercial districts to be developed with up to an additional five (5) feet of height, provided the first floor has a minimum height of 12 feet from the base flood elevation plus maximum freeboard, to the top of the second floor slab. This would provide for the ability of the ground floor to be placed at a lower level, while providing sufficient ceiling height for the ground floor to be raised at such time when roadways and sidewalks are raised. It should be noted that the additional height would NOT be applicable to the west side of Alton Road from 6th Street to Collins Canal, where the height limit was already recently raised from 50 feet to 60 feet for purpose of providing added resiliency.
The following sections illustrate examples of current and proposed conditions related to the subject ordinance:
Example 1 / Existing Code
The following section shows an example of a typical 5-story commercial building located in a CD-2 district, with a maximum height of 50 feet, as measured from the maximum freeboard, which is BFE + 5 feet. In this example, if streets and sidewalks were raised to the elevation of BFE + 5 feet, it would result in an undesirable commercial ceiling height of less than 10 feet.
Example 2 / Proposed Ordinance With 5 Foot Increase
The following section shows an example of the same 5-story commercial building located in a CD-2 district, with the proposed increased height of 5 feet and including a minimum height of 12 feet from BFE + 5 feet to the top of the second floor slab. This would allow a much more desirable future commercial height of at least 12 feet if streets and sidewalks are raised in the future to as high as BFE +5.
The minimum 12 foot height requirement shown above also ensures that the bulk of the additional height will be incorporated into the first level for enhanced resiliency, and will encourage the construction of resilient buildings that will better adapt to flooding and rising sea levels.
The proposed ordinance also amends and expands allowable height exceptions for sustainable roofing systems and alternative forms of energy. This includes solar roofs, blue roofs, white roofs, cool roofs, green roofs, and rooftop farming systems, along with solar panels, wind turbines, and other alternative energy fixtures as allowable height exceptions in all districts except single-family districts.
PLANNING BOARD REVIEW
The Ordinance came before the Planning Board on April 25, 2017, and was continued to a date certain of May 23, 2017. On May 23, 2017, the Planning Board transmitted the proposed Ordinance Amendment to the City Commission, with a favorable recommendation. The Planning Board also recommended the following modifications:
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Include the Town Center (TC-1, TC-2 and TC-3) Districts in the ordinance.
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The allowable additional height shall be increased from the proposed five (5’) feet to ten (10’) feet, in order to provide more flexibility for interior floor heights on upper levels.
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The allowance for an increase in height should not be discretionary on the part of the DRB or HPB, but instead should be an allowable increase as of right. Specifically, the Board has recommended the following change for each zoning district:
Notwithstanding the above, the Design Review Board or Historic Preservation Board, in accordance with the applicable review criteria, may shall allow up to an additional five (5) feet of height.
SUMMARY
The proposed modifications to allowable building heights within commercial districts will better adapt new commercial structures to future increases in roadways, sidewalks and right-of-ways. In this regard, as drafted, the additional five feet in height proposed will help ensure that the first level of new commercial buildings will be constructed in a manner that will allow for viable space in the future, when streets and sidewalks are raised.
As it pertains to the Planning Board recommendations, the TC districts have been included in the revised draft; this corrects an oversight in the initial drafting of the ordinance. With regard to the proposal to allow for an increase of up to 10 feet in height, as opposed to 5 feet in height, as indicated previously, the Administration believes that is a better option. By giving the DRB or HPB additional latitude with regard to maximum height, more flexibility will be provided for the floor-to- floor height of upper level interior spaces. Further, the minimum interior height requirements for the first floor will ensure that the increase in height will not be top heavy.
The following section shows an example of a 5-story commercial building located in a CD-2 district, with an increased height of 10 feet and including a minimum height of 12 feet from BFE + 5 feet to the top of the second floor slab. In addition to allowing a much more desirable future commercial height of at least 12 feet if streets and sidewalks are raised in the future to as high as BFE +5, more flexibility for upper floor ceiling heights is provided.
The Administration did not recommend that the discretion of the HPB or DRB to allow for an increase in height be removed. In this regard, the DRB or HPB should have the discretion to allow up to 10’ in height, with minimum first floor standards as proposed. In some instances, depending upon the number of floors proposed, the existing grade of the site and the surrounding context, the entire additional height may not be needed.
UPDATE
On June 7, 2017, the City Commission approved the subject Ordinance at First Reading, as recommended by the Administration, inclusive of the following, which are included in the revised Ordinance:
1. A modification for the allowable additional height to be increased from the proposed five (5’) feet to ten (10’) feet;
2. The inclusion of Town Center Districts; and
3. Retention of the discretion of the Historic Preservation Board and the Design Review Board, as it pertains to the proposed increase in height.
The City Commission also directed the Administration to further study the proposed 25-foot exception for renewable energy systems, particularly wind turbines. In this regard, the revised ordinance has also been modified to limit the height exception for wind turbines to oceanfront properties. The reason for the proposed allowance of wind turbines as a height exception on oceanfront properties is two-fold:
1. In order to maximize the effectiveness of wind turbines, a continuous wind, at higher elevations, is required. Ocean front properties are the best suited lots for this.
2. Oceanfront properties are primarily zoned RM-3 and R-PS4, which have the highest residential height allowances. As such, when combined with current allowable height exceptions, such as mechanical rooms, cooling towers, and stair and elevator bulkheads, wind turbines are not expected to have a significant visual impact.
Finally, the Historic Preservation Board discussed the proposed ordinance on July 11, 2017 and recommended that any allowable increase in height be limited to five (5’) feet within local historic districts.
CONCLUSION
The Administration recommends that the City Commission adopt the Ordinance.