Factors to Consider:
Gross Area
The program area (assignable net square footage) such as an executives office.
General Circulation (shared square footage) such as hallways.
Other non assignable square footage but necessary to a building's operations like mechanical and equipment areas.
Number of Floors
Program may require several floors.
Zoning Requirements - May limit the number of floors or set backs which could change the base footprint.
FAR
The floor area ratio balance changes the base footprint. The FAR controls how large a building can be based on the size of the property.
Building Configuration
First floor, mezzanine, equipment, penthouse, and rooftop floors will differ from the others.
Site
Unique site factors such as a dramatic slope, marshland, or toxic soil may change a building's footprint.
For a site in the Northern Hemisphere an orientation between 5 and 25 degrees east of south best achieves the balance of summer and winter heat gains.
Site access may dictate entry and exit locations as well as deliveries.
Topography and micro climate are important factors like winds, location of trees, and distance to water.
Views are often a concern in areas such as the Hollywood Hills or in Santa Barbara
Utilities and Infrastructure
Sun Angle
Climate (Macro and Micro-climate)
Cost and Value
The higher the perimeter to floor area ratio; the greater the unit cost.
The greater the floor area; the lower the unit cost.
Maximizing square footage of a lot may be a priority of the client. This is common in highly competitive markets.
Design
Earth berm shelter - creates energy savings
Waterfront Views - Value of land may necessitate its use
Podium for parking (Theaters) or commercial business (mixed use)
Iconic forms such as the Ordos Museum have a unique footprint.