The first variable used is the Opportunity FAR Ratio. According to the American Planning Association (1958, p. 3), the Floor to Area Ratio (FAR) expresses the relationship between the amount of usable floor area permitted in a building (or buildings) and the area of the lot on which the building stands. It is obtained through the following formula: Floor Area / Lot Area. In practice, this ratio is usually constant for a zone. A floor area ratio of 1.0 means that floor area may equal lot area, while a FAR of 5.0 means that the floor area may be up to five times as large as the lot area. Though a floor area ratio affects volume, shape, and spacing of buildings on the land, it does not determine a particular shape or spacing. Rather, it permits choices.

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Using FAR as its basis, the Opportunity FAR Ratio (Boston Symposium Class, 2017; Valecillos, 2017) was developed to determine the parcels with the highest possibility for development. It is calculated as follows:

Current FAR= Actual Floor Area / Actual Lot Size

Zoning FAR= FAR determined by Zoning

Opportunity FAR Ratio = (Zoning FAR/Current FAR) – 1

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We used parcel data through ArcGIS to pinpoint those parcels that had an Opportunity FAR Ratio of 1 or higher. The sum of the square footage of all those parcels for each buffer or study area (0.5 miles around the stations) was later used to rank them in a scale from 1 through 5.

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The next variable utilized is the Exempt Vacant Land. In this case, we also analyzed property data through ArcGIS to identify those parcels part of the exempt categories and that had zero (0) current FAR. The sum of the square footage of all those parcels for each buffer or study area (0.5 miles around the stations) was later used to rank them in a scale from 1 through 5. Those parcel with less than 1000 square feet were not counted.  

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We were also able to locate those parcels that had zero (0) current FAR and that were not identified earlier as exempt. We used those parcels to define the next variable called Private Vacant Land. The sum of the square footage of all those parcels for each buffer area (0.5 miles around the stations) was later used to rank them in a scale from 1 through 5. Those parcels with less than 1000 square feet were not counted.

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Finally, we stated our fourth variable as Residential Land Use Disparity Score. This measure shows the difference between actual residential land use and residential zoning. The calculations give a score on both zoning and current residential use of 1 to all one to two family residences, a score of 2 to those three family and four to six family apartment complex, and a 3 to all those above (Valecillos, 2017). The idea is to take the zoning score and subtract the actual land use score for each residential parcel. The sum of the differences for all the parcels within each buffer area (0.5 miles around the stations) will later be used to rank them in a scale from 1 through 5. Those parcels with less than 1000 square feet were not counted.

Defining physical opportunity scores for each buffer area

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The first stage is to determine an average score in terms of the physical opportunity variables for each station area. To do that, we first ranked all the station scores from lowest to highest. The lowest got a score of 1, while the highest got a 5. Then, we used the interpolation formula to provide a score to all other study areas.

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