NPD p1 (b)

Jodie, let me run through the BH-SW calculation, and then answer your questions. First, the ‘street width’ part of the ratio should be converted to ‘street centerline’ or BH-CL. Measuring to the centerline instead of full street width allows you to do each side of a street individually, including internal streets that have two sides or frontages within a project boundary, and bordering streets where only one side or frontage is inside the boundary. Note that NPDp1 applies to both existing and planned streets. For each street frontage (see Fig 13 in the Reference Guide Getting Started chapter for a diagram of the term), determine which buildings on that frontage meet the minimum BH-CL ratio, which is 1:1.5 (or half of the 1:3 BH-SW ratio), or 1:0.5 for non-motorized ROWs. Any side of a building that faces a street must be considered, not just front facades. For each building (existing and planned buildings for NPDp1), divide its height by the façade-to-centerline distance; if the result is less than 1.5 discard the building; if the result is 1.5 or greater, add the width of that building façade to a list of qualifying buildings and sum the total when all buildings have been screened. Then add up the length of all street frontages, and subtract the width of all driveways and alleys on the frontages to get a net total street frontage length. Finally, divide the total width of qualifying buildings by the net total frontage length to see if you make the NPDp1 15% threshold (or 40% if you're attempting NPDc1).

So to your questions:
- Buildings don’t have to be located directly opposite each other on a street because the calculation method treats each side of a street individually regardless of what’s on the opposing side.
- Park frontage isn’t an allowable exclusion from total street frontage, only driveways and alleys.
- The sidewalk you describe between rows two and three can only be used if it’s located in a dedicated right-of-way. If it is in a dedicated ROW, then you can use the houses even if their rear side faces the sidewalk because the calculation is blind to which side of a building is facing the frontage.

Hope this helps, Eliot

The facade-to-centerline measurement only applies to buildings, so the park never enters that part of the calculation. The only way the park is involved is with its frontage length making up part of total street frontage length.

Jodie, I need to make a correction to my original answer that I failed to proof read sufficiently. The threshold for a qualifying building is not 1.5, it is 0.66, or the ratio of 1 to 1.5.
Eliot

Jodie: We have developed a spreadsheet that essentially automates the calculation procedure that Eliot describes above. If you -- or anyone else on the list -- wants a copy, please send a request to me at tbardacke@globalgreen.org and I'll pass it on.