Search This Blog

Monday, November 29, 2010


            Design with space depends on the concept of core area development capacity and its relationship to the off-setting project open space provided. (Core area is the land remaining for building mass and parking after all other demands are subtracted from a gross land area of any size. If parking is not required, or placed underground, the entire core area is available for building mass that is often referred to as building height and area.)

            Table 1 explains the distillation of core area. Public rights-of-way and improved or paved easements, if present, are first subtracted from a gross land area. (If this is a forecast the area subtracted would be an estimated percentage of the gross land area.) The net land area remaining is further reduced to buildable land area by subtracting all unbuildable areas such as, but not limited to, ravines, marshes, ponds, and unstable soil, if present. Buildable area is reduced to core area by subtracting the open space present or planned in addition to miscellaneous pavement, driveways and loading areas. (If this is a forecast, the areas subtracted would be estimated percentages of the buildable land defined.) The core area that remains is available for building mass; and parking, if required. (Parking is only open space in the minds of those who wish to increase intensity.) When reviewing Table 1, keep in mind that the areas mentioned can represent those of one project, or the sum of many areas within a larger plan.
After core area is identified, it becomes possible to forecast gross building area potential based on the forecast model chosen and the design specification values entered. This potential has been called development capacity, and the square feet of gross building area present or predicted per buildable acre has been called intensity. Intensity can be calculated per gross or net acre; but when large unbuildable areas are involved, these statistics distort the intensity that people experience within the buildable area.

The choice of a development capacity forecast model is influenced by the land use category involved, but this is a simple choice among residential, non-residential or mixed-use alternatives. A non-residential choice would lead to Table 2. A series of decisions in Table 2 leads to a forecast model. The first decision involves the parking system contemplated. This leads to a choice among the parking design options available within the system chosen. From this point, the path leads to one of two forecast models. The choice depends on the information given. Gross building area predictions are based on a given gross land area. Gross land area predictions are based on a given gross building area objective. The given areas can be of any size and do not need to be restricted to one project.

For instance, if the CG1L forecast model is chosen in Table 2, Table 3 illustrates values that can be entered in its design specification template to forecast the core area of a given gross land area. Additional values are entered to calculate the development capacity of this core area in the GBA column and the intensity of this capacity in the SFAC column. Any change in the values entered alters the forecast. If the open space percentage is increased from 30% for instance, core area shrinks along with gross building area capacity, or design specification values must be adjusted to maintain the same capacity. If open space is decreased, the core area increases along with its gross building area potential unless other specification values are also modified.

It should be apparent that open space is a major design specification value that affects the amount of core land area available within our built environment. When combined with other design specification values, it determines the scope of activity and population that can be sheltered within any specified area. Context refinement adds form, function and appearance to intensity decisions that lead to the places we create.

Building height can be increased within a core area, parking requirements can be eliminated and open space can be reduced in the buildable area to increase core area intensity, but these options can be used to extremes that prompted original efforts to protect the public health, safety and welfare.  When these options are exhausted, the only way to increase core area development capacity is to buy more land. This is the dilemma we face on a planet of limited resources and expanding population. Open space must be protected beyond the artificial environment we build to ensure the survival of life on the planet, but it must be protected within the places we build to relieve intensity. The specifications required remain to be determined, but common sense should tell us that open space is essential to our quality of life and agricultural capacity, while also part of an ecology of survival we threaten with unlimited consumption.

Footpaths document our first explorations of space, but the land discovered is simply an island in a sea protected by a thin film of atmosphere at risk. Improved movement systems expanded our control. Shelter was built and life support systems were extended. As a result, land was converted from its natural function to an artificial domain we call the built environment. In my lifetime this domain has expanded to serve growing populations while inner cities have been abandoned to escape intensity. This has produced sprawl without economic stability that continues to threaten its source of survival.

Sprawl tells me that we have not learned to design with space as we construct the four divisions of our built environment. We use too much or too little and mistakes are reflected in blight, social alienation, economic instability and psychological distress. We have all seen horrendous relationships among shelter, movement, open space and life support structures within cities. We consider open space a void to be “improved” and resistance is considered “taking”. Sprawl continues as we struggle to recognize natural realities that face our abstract world with a power we cannot dominate without consequences.

It is becoming apparent that we must adapt to life within limits since the space beyond cannot be consumed indefinitely. It also means that we must adapt our concept of agriculture to resist urban sprawl; to adapt open space requirements within cities to offset excessive intensity; and to recognize that life within limits will require the redevelopment of blight rather than the abandonment of central cities. This does not mean that economic penalties can be imposed on those saddled with the mistakes of our past, but that our abstract financial concepts must adapt to recognize the goal, which is design with space that protects the survival, patterns and dignity of all life on the planet.

We have much to learn about the space that must be protected beyond our cities and the space we must preserve within, since shelter and movement options can respond to population growth with overwhelming intensity. We are now coming to realize, however, that low intensity cannot serve population growth without threatening the health, safety and welfare of the planet.

Learning to shelter the activities of expanding populations within geographical limits will require a thorough understanding of intensity and context design. Anything less will continue our consumption of a planet that cannot speak, but who reacts without compromise. It is we who must learn its language, since it has no need to explain that we are not a gift. It is the gift and we are expected to take responsibility. Forecasting our development capacity options within sustainable limits is a step in this direction.

Author Note: Land Development Calculations has been written to assist many professions who wish to build the knowledge required to design with space. It forecasts development capacity in relation to the land consumed. This unlocks the ability to forecast anything that is a function of the gross building area predicted such as, but not limited to, construction budget, population capacity, traffic generation, return on investment and yield per acre (for comparison to a city’s average annual operating expense per acre).
The following articles can be read on my blog, Cities and Design, at

1)             "Replacing Density" discusses its leadership weakness and intensity alternative,
2)             "The Limits of Shelter Capacity" provides expanded detail regarding intensity,
3)             “The City is a Farm” discusses the relationship of intensity to economic development,
4)             "The Disorganized Zoning Ordinance" outlines the legislative confusion that impedes leadership progress,
5)             “Examining Architecture” takes a closer look at a piece of the city design puzzle,
6)             “The Variance Trap” illustrates development regulation weakness with a residential forecast model from the Development Capacity Evaluation (DCE) software collection,
7)             “City Design with Space” discusses the overlooked role of project open space with a non-residential forecast model from the DCE collection,
8)             “The Core of Our Built Environment” identifies the nucleus of development capacity
9)             “Ponzi Schemes and Land Use Plans” offers an alternative to annexation and sprawl.
10)         “Where Does Sustainability Begin?” discusses the importance of land in a competition between our natural and built environments.
11)         “Economic Development Is Missing a Strategy” discusses the intelligence and strategic planning required to identify economic development objectives on the road to a sustainable future.

These articles have been deleted from my blog but are available upon request:

1)             The Concept of City Design” includes an overview and suggested research agenda,
2)             “Politics and Planning” is an argument in support of the effort, and
3)             “Context Measurement” outlines a suggested research yardstick.

No comments:

Post a Comment