BIRTH
OF THE MIAMI 21 CODE - A PROGRESSIVE FORM-BASED CODE
After
a four-year gestation involving over 500 meetings of careful consideration
and long deliberations a new zoning code to be known as the "MIAMI
21 CODE" has finally been born. MIAMI 21 represents the new
holistic approach to land use and urban planning taking root in
a major Florida metropolis. Says Alexander Adams of the City's Urban
Design Section "In a time when many legislators and localities
are looking to relax rules for growth and environment, through MIAMI
21 we are attempting to strengthen the urban design, include Transit
Oriented Design incentives, revise the bonus structure for many
key community building needs including affordable housing, brownfield
redevelopment, parks and open spaces enhancement, historic preservation
and transfer of development rights, as well as, factoring in energy
conservation through LEED certification.
"Miami
is a dense unique locality that is fully built out and will depend
on redevelopment of the urban areas to enhance the built form. As
a form based code, MIAMI 21 places primary emphasis on the physical
form of the built environment with the end goal of producing a specific
type of place. It is a community planning and design option that
many Florida communities may want to carefully watch and consider
incorporating wholesale, or in part, as a means to counter the built-in
sprawl producing effects of conventional zoning regulations.
"The
principles, which underpin Miami 21, stand in contrast to the car-is-king,
suburban template of parking lots, blank walls, exposed garages,
obtrusive driveways and set-back, isolated buildings that under
the current code had long dominated -- and deadened -- city streets"
(Adapted from "Can Miami 21 Plan Replicate Biscayne Boulevard's
Revival?" by Andres Viglucci of the Miami Herald). In addition,
as a form-based approach, careful attention is given to community
design, density/intensity and land use mix transitions along geographic
transects or slices.
Transect
Zones, Thoroughfares, Buildings and Landscapes
As a "form-based code", Miami 21 lays out the community's
desired form of development as components of particular transect
zones, thoroughfares, buildings and landscapes. The Code prescribes
development form requirements in these areas to achieve the desired
community vision. It provides building-form prescriptions of what
a community wants to be rather than a set of rules prohibiting what
cannot be built. The urban context is considered within the Miami
21Code and is comprised of a series of components - neighborhoods,
corridors, urban centers, and districts - each with its own arrangement
within transect zones. In all cases, the goal of transit-oriented,
pedestrian-friendly, mixed-use urbanism guides the arrangement of
transect zones, thoroughfares, buildings and landscape.
Transects
& Zones
Miami 21, and other form-based approaches, encourage development
pattern progression based on the organizational principles of transects.
A transect is defined as a geographical cross-section that reveals
a sequence of zones or system of ordering habitats based on the
physical character of a built place and managed environments. Each
transect is managed based on the building's configuration, setting,
relation to the street, uses, heights, floor ratio, density, and
transitions between successional zones. The elements within each
zone are calibrated by their location on the transect scale from
the most natural to the urban downtown. For example, the Miami 21
transect zones are: Natural (T1), Sub-Urban (T3), Urban General
(T4), Urban Center (T5), and Urban Core (T6) with several maximum
heights. Other specially defined zones were created to blend the
existing zoning of Miami including Civic Space (CS), Civic Institutional
(CI), Civic Institution - Health District (CI-HD), Light Industrial/Work
Place (D1), Industrial (D2) and Waterfront Industrial (D3).
Pragmatically,
for each transect zone the allowable uses, density, intensity, parking,
building frontages and setback standards are displayed using a series
of matrixed tables and graphical depictions in addition to the normal
zoning text to describe intended outcomes. Through application of
transects and zones the mix or variety of allowed uses are regulated
less by the traditional segregation of land uses and more so in
terms of allowable buildings, building heights and densities. This
is a move away from the modular one-dimensional, segregated land
use approach of conventional zoning and much more permissive of
mixing allowable uses. To preserve the character and tranquility
of existing neighborhoods a series of established setback areas,
neighborhood conservation, and historic districts were carried over
from the existing zoning code. Successional zoning only allows adjacent
zoning changes to the next more intense transect category respecting
or requiring appropriate transitions across abutting transect zones.
Emphasis on Public/ Private Spaces Interaction - A Major Component
of Public Open Space
Within the Miami 21 form-based code, urban form is characterized
by a set of interdependent elements that create a sense of place.
These include thoroughfare type, building type, frontage type, and
the arrangement and disposition of landscape and lighting. Thoroughfares
provide cities with a major percentage of public open space and
what is often referred to as the public realm. Thoroughfares also
function to provide moving lanes for vehicles, bicycles, walking
and transit. A thoroughfare is associated with a particular type
of movement, and is endowed with two attributes: movement type and
character. Under Miami 21 the movement type of the thoroughfare
refers to the number of vehicles that can move safely through a
segment within a given time period; it is physically manifested
by the number of lanes and their width, by the centerline radius,
the curb radius, and the super-elevation of the pavement. The character
of the thoroughfare refers to its suitability as a setting for pedestrian
and bicycling activities physically determined by the associated
frontage types as determined by the transect. This is very different
from a conventional code where thoroughfares pass through, or along,
modularized land use types without regard to form or character adaptations
- the road is the defining character rather than the community.
