Consider what follows as an illustration of the type of sustainable, transit-oriented community that might be created in a greenfield situation.
Here is a satellite image of an illustrative site.
The straight line running top to bottom, just right of center, is a lightly-used rail line which could serve as the transit link between a community and other communities in the area
The next image shows one possible arrangement of the community features discussed in Section 3 “Goals” (above).
The red line is the railway. As it passes through the community area, it would be surrounded by a protective berm planted with trees and shrubs as a noise barrier. Midway between the north and south boundaries of the development area is a station with retail space (tan), surrounded by a small, urban park (green). If you were to get off a train here, you would find a four-block mixed use area with shops, office space, and apartments or condominium properties. The buildings here would be perhaps four stories high, with green roofs and 2-3 levels of parking beneath. Walking further out from the center, you would come to two or three blocks of single-family houses of varying sizes, before arriving at the eco-ring which surrounds the entire community.
The community needs to have a robust population size in order to support the investment. To estimate the population, the layout in the next image was roughed out. It should be understood not as a design suggestion but as a tool for answering the question, “How many people could live here?” An approximate number is arrived at by estimating the average number of people for each type of housing unit.
The table below shows the calculations based on this hypothetical community layout, arriving at a total of 9,772 potential inhabitants.
Green Community: Theoretical Residential Capacity |
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Single-family homes |
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House type |
Blk Len Ft |
Blk Wid Ft |
Blk Area SqFt |
Lots per acre |
Lot Area SqFt |
Houses per block |
Avg. Occu-pancy |
Avg. pop/ block |
Blocks |
Houses |
Residents |
|
1 |
Larger (triangular blocks) |
800 |
800 |
320,000 |
4 |
10,890 |
29 |
4 |
118 |
4 |
118 |
470 |
2 |
Moderate |
700 |
500 |
350,000 |
8 |
5,445 |
64 |
4 |
257 |
4 |
257 |
1,028 |
3 |
Small ("townhouse") |
900 |
700 |
630,000 |
16 |
2,723 |
231 |
3 |
694 |
2 |
463 |
1,388 |
4 |
Tiny |
900 |
250 |
225,000 |
24 |
1,815 |
124 |
1.3 |
161 |
4 |
496 |
645 |
Total |
3,532 |
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Apartments/Condos |
Len Ft |
Wid Ft |
SqFt |
|
|
Units per block |
Avg. Occu-pancy |
Avg. pop/ block |
Blocks |
Units |
Residents |
|
5 |
Central land area |
1500 |
1500 |
2,250,000 |
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6 |
Less park & station |
900 |
750 |
675,000 |
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7 |
Less streets & courts |
1,250,000 |
||||||||||
8 |
Space per floor |
325,000 |
||||||||||
9 |
Residential floors |
3 |
||||||||||
10 |
Total residential space |
975,000 |
||||||||||
11 |
Space per apartment |
1,250 |
||||||||||
12 |
|
|
|
|
780 |
2.0 |
1,560 |
4 |
3,120 |
6,240 |
||
Total Estimated Residential Capacity |
|
|
|
|
9,772 |
Notes on the Calculations
Some have expressed doubt about the calculations in this table. That doesn’t surprise me, since I was amazed at the results myself, particularly of the residential capacity of the mixed-used apartment area. Here is the background of each estimate, keyed to the number of each row in the table.
Calculating potential apartment population is a bit more complicated due to the irregular shape of the apartment area and the need for open courts within the buildings themselves. Given the shape of the area allocated for the center of the development – transit station, park, streets, and mixed use areas – we start with the total area of the center and subtract the non-residential areas within it:
The total population including apartment/condo and home residents would be 9,772. Of these, approximately 64% would live in apartments or condos, 7% in “tiny houses”, 14% in townhouses, 11% in moderate size houses with individual yards, and 5% in larger houses.