Shelter capacity is the gross building area present or planned per acre of buildable land area. It can be occupied by any activity and is created by multiplying floor plan area times floor quantity. The relationship of building mass and activity to location became regulated by local city planning and zoning ordinances after excessive shelter intensity became recognized as a physical, social, and economic threat to the public, health, safety, and welfare. Attempts to measure intensity focused on the concept of density in residential areas and on the floor area ratio in non-residential areas. These separate measurements were the first indication that occupant activity, location, and physical intensity were being confused, because there is only one measurement for the intensity imposed by building mass in a neighborhood. Occupant activity and location are independent issues. They may magnify massing intensity but are not the root decisions that determine the magnitude of its presence. This is why I have pointed out that gross building area may be occupied by any activity. The scope of this activity is limited by the gross building area available. Massing intensity, therefore, is first a function of the gross building area per buildable acre planned or present. (I won’t complicate this axiom with its specific equation or with mention of the building design categories and design specification topics that combine to produce massing intensity options.) Massing, or shelter, intensity can be magnified by occupant activity. It can also be influenced by the quantity of pavement, movement, and life support that serves it in a designated location. This is physical intensity. It is ameliorated by the amount of unpaved open space planned or present on the premise and in the surrounding area.
A master plan is a two-dimensional map created to separate
incompatible activity in a city. Its intent is defined by the regulations in a
zoning ordinance. These decisions alone represent a continuing source of
disagreement in some circles, but the preoccupation with relationships has
distracted attention from the fundamental issue. A city’s ability to support
itself is a function of the taxable potential of its land use areas, and some
of these areas must be subsidized by others. The revenue potential of each
area, or zone, is a function of the average revenue received per sq. ft. of occupant
activity times the gross building area present. In other words, the
relationship of activity to intensity within a zone determines a large portion
of its revenue potential, and a city is obligated to match its annual cost of
operation, maintenance, capital improvement, and debt service per acre with the
average revenue it receives per acre from all zones. A city that does not understand the revenue
potential of its zones will continue its efforts to balance an equation it does
not understand and cannot compute. The inevitable result has been sprawl and
excessive intensity built with an inadequate understanding of shelter capacity,
intensity, activity, and revenue relationships. This is occurring on land areas
that growing populations cannot expect to continue consuming indefinitely and
survive.
I have contributed the conceptual framework and technical
information needed to continue this discussion in my book, “The Equations of
Urban Design”. It is available on Amazon.com but the title may have been an
unfortunate choice since the book is not consumed with equations. They are
simply the foundation on which the conceptual, predictive, and measurement
format is based. I have also published over 190 essays regarding this topic at
my blog www.wmhosack.blogspot.com.
It has been visited by over 32,000 readers. About half-way through this
blogging effort I also realized that I could publish essays on Linked-In.
There is a lot of work to be done to reach the only goal that matters. Symbiotic survival is not an option. It is a mandate that will not be met until our habitat ceases to be a threat to ourselves and its source of life - the Natural Domain.
IN OTHER WORDS
The activity located within gross building area produces profit per sq. ft. and revenue per acre occupied. Profit per sq. ft. is of interest to the private sector. Revenue per acre is of interest to the public sector. Profit is carefully considered. Revenue is minimized by profit-making decisions, but indicates the ability of municipal land to support essential public services. There are many revenue options that are a function of the gross building area design specification decisions adopted. These determine the use of land for shelter capacity and intensity, but cities have been preoccupied with the compatibility of land use activity. They have lacked the tools and information needed to compute the full potential of the land involved –- and of all land within their boundaries. As a result, they cannot begin to consider the contribution of land and its shelter capacity to any comprehensive strategy for economic stability, let alone survival. This extremely limited perspective and random use of land development potential for shelter capacity has led to the sprawl and excessive intensity we currently create in a blind search for “balance”. Unfortunately, the current result is a city that struggles to produce the revenue it needs to shelter the activities of growing populations without sprawl and excessive intensity.
In other words, the ability to predict the gross building area potential of a city's land area combines with the occupant activity permitted to determine its economic potential to protect the health, safety, and quality of life of its population. In more provocative words, a city that permits shelter capacity to be a private sector decision abandons the productive potential of its land area to support a growing population within sustainable limits.
Walter M. Hosack: September, 2022
