NOTE: The three tables mentioned are located at the end of this text.
The industrial revolution sheltered urban activity with excessive intensity and lack of concern for the public health, safety, and welfare. Tenements symbolized the abuse and intensity remained an obvious presence with an inadequate definition. Centuries of abuse culminated in the 20th century with a battle over human rights at a time when individual freedom to dominate was unrestrained by the collective freedom to demand a better quality of life. The battle eventually produced zoning plans to separate incompatible land use activity, annexation plans for expansion into agricultural areas, density plans to limit population compression, setback plans to separate building mass within neighborhoods, and building codes to improve the safety and hygiene of shelter design and construction. Unfortunately, this did not solve the fundamental problem of excessive intensity. It could only be defined with emotion that inevitably gave the term negative connotations. The automobile stimulated flight from excessive intensity, experiments with minimum lot sizes began, and suburbs started to form a pattern now referred to as sprawl. It was first mapped as a symbol of growth and success. Aerial photography over time has caused instinct to anticipate a visible symptom of disease as the pattern of sprawl, with pockets of excess intensity, began to form sectors and rings around a core of deterioration that continues to metastasize across the face of our planet. Sprawl begins with an inadequate understanding of shelter intensity. Intensity can actually be a beneficial prescription for the shelter of growing activities within limited geographic areas when it is understood and carefully correlated with relational databases.
Architectural intensity is like blood pressure. It can be measured and predicted with the following equation
EQUATION (1): Intensity = Shelter Capacity * Impervious Cover / 10,000, or
INT = SFAC * IMP% / 10,000
Shelter Intensity (INT) is an emotional-psychological response to the relationship of building mass, building height, parking, pavement, and unpaved open space on one or more project areas.
Shelter Capacity (SFAC) is the gross building area present or planned in sq. ft. per buildable acre.
Impervious Cover (IMP%) is the percentage of a buildable land area that increases storm water runoff from that produced by land in its natural state. (E.g. building cover and pavement)
Buildable Land Area (BLA) is the project area that remains in sq. ft. after existing or contemplated rights-of-way, paved easements, and unbuildable areas are subtracted. (This term should not be confused it the more common zoning expression that often means the land area located within the building setback lines on a given lot.)
It has not been possible to accurately predict the vast number of feasible shelter capacity options for a given buildable land area in a brief period of time. The alternative has involved time consuming site plan evaluation of very few options at the drawing board, and intensity has been determined by what will fit on the land available. It is possible, however, to define shelter capacity with a deceptively simple equation.
EQUATION (2): Shelter Capacity = Gross Building Area / Total Buildable Acres Occupied, or
SFAC = GBA / BAC
Gross building area predictions forecast total potential floor area within a simple abstract volume that will contain all ensuing architectural features.
Gross building area measurements include all existing floor area beginning at the exterior perimeter of a building.
Buildable acres (BAC) is equal to buildable land area in sq. ft. divided by 43,560 sq. ft.
EQUATION (3): When the equation for SFAC in Equation (2) is substituted for SFAC in Equation (1), Equation (3) becomes a consolidated expression for architectural intensity.
INT = (GBA * IMP%) / (BAC * 10,000)
The fly in the ointment has been an inability to accurately forecast all gross building area options (GBA) for a given land area in less time than it would take to prepare a single site plan; a consistent definition of buildable land area; and a lack of research to define “excessive” architectural intensity. This lack of knowledge and forecasting ability has prevented the careful correlation of shelter activity, capacity, and intensity within limited geographic areas that protect our physical, social, psychological, environmental, and economic quality of life.
To start at the beginning, there are now two worlds on a single planet. The Built Domain is currently sprawling to shelter the activities of growing populations, and this threatens our source of life with its land consumption. The Built Domain contains Urban and Rural Phyla, and both phyla contain a Shelter Division that is served by its Movement, Open Space, and Life Support Divisions.
We need credible intensity measurement, evaluation, prediction, and correlation with related social and economic databases to connect shelter capacity, intensity, and activity options with their many quality of life implications.
There are six building design categories that provide the overwhelming majority of shelter capacity throughout the world. Gross building area options related to each category are a function of the values assigned to the topics in their design specification templates. A category algorithm and master equation correlate these values with floor quantity options to predict gross building area alternatives, and accurate gross building area predictions make it possible to forecast intensity options using Equation (3). A definition of “excessive” can then be written with the help of research measurement and evaluation.
Table 1 is an example of a specification template and forecast panel for the G1 Building Design Category. Forecasts are based on the specification values entered in its Land Module, Pavement Module, and Building Module. The gross building area predictions in cells B42-B51 and the intensity predictions in cells G42-G51 are based on the specification values entered, and one or more of these values may be modified to test additional options.
Table 2 presents an abbreviated matrix of the intensity options that can be produced by a building design category and its template of design specification variables. At this point it is not possible to draw conclusions regarding “excess” within the table, but measurement of existing conditions can produce the knowledge required.
Shelter intensity at the project level is simply an objective within a city design strategy, however, because projects combine to form neighborhoods, districts, cities, and regions. City design is the correlation of project activity, shelter capacity, and intensity within limited geographic areas to protect a population’s health, safety, quality, and source of life.
I’ve attempted to keep this as brief as possible in an attempt to convey a concept without complication that runs the risk of confusion, but I’ve mentioned shelter alternatives called building design categories without explanation. I’m including a list for reference in Table 3. Each category is represented by two forecast models. Two are required because: (1) Land area may be given and gross building area options must be found, or (2) A gross building area objective may be given and land acquisition options must be found.
I wrote my third book in 2016 entitled, The Science of City Design, for those who wish to know more. It can be found in paperback and e-book versions on Amazon.com and is intended to introduce a quantitative language that can address the very practical and very emotional dimensions of shelter intensity within limited geographic areas that must be defined before we can hope to reach a state of symbiotic survival.
Copyright: Walter M. Hosack, 2018. All Rights Reserved