There are 739 buildings on 755 parcels in the DDA (some parcels have more than one building); some parcels have less than one building (a building overlaps more than one parcel), as with One North Main, Campus Inn, and Sloan Plaza.  Some of the new buildings, on vacant land or surface parking lots, also overlap more than one parcel, as in the Brown block or the Library block...and elsewhere in the yellow layer.  There are 418 parcels in the set of target parcels (see below* for definition) and 405 buildings on target parcels (again, some overlapping parcels but more frequently, there are multiple buildings on a single parcel).

Vacant or Surface Parking parcels

• Square footage of vacant parcels in the DDA:  770,346 square feet.
• Square footage of target vacant parcels in the DDA:  620,008 square feet.  Buildout to the 2/3 level, in 400,000 square feet, in 10 story buildings (covering the parcels) would provide 4,000,000 square feet; in 12 story buildings, 4.8 million square feet.

• DDA parcels, total:  8,269,459
• Target* DDA parcels, total: 3,503,980

Thus,

• If half of each target parcel's footprint were covered, there would be about 1.75 million square feet to work with.
• If we need to generate 7.5 existing plus 5 million new, then that means each parcel, on average would need to support a building of 12.5 / 1.75 or  about 7 stories.
• If we need to generate 7.5 existing plus 2 million new, then that means each parcel, on average would need to support a building of 9.5 / 1.75 or  about 5.5 stories.
• If 1/3 of each parcel's footprint were covered, there would be about 2 million square feet to work with.
• If we need to generate 12.5 million, then that means that on average each building would be 6 stories.
• If we need to generate 7.5 existing plus 2 million new, then that means each parcel, on average would need to support a building of 9.5 / 2 or  about 4.75 stories.
• If 1/4 of each parcel's footprint were covered, then there would be about 2.325 million square feet to work with:
• If we need to generate 12.5 million, then that means that on average each building would be 12.5/2.325 or 5.4 stories.
• If we need to generate 7.5 existing plus 2 million new, then that means each parcel, on average would need to support a building of 9.5 / 2.325 or  about 4 stories.

Building inventory, smaller than parcel inventory
The following table answers the following questions:
     How many square feet are there currently in the built buildings?  How many if all premiums were used?  How many if all buildings less than 6 stories were to grow to 6?
     In the target population, using building footprints, same questions as above--then, how many new square feet are brought in, in the target parcels, by such vertical add-ons?
 

May 10:
Response to public hearing in relation to 3D model buildout:

• Square footage of yellow layer, increased coverage coming from height reduction, all on vacant or surface parking parcels, 8, 10, 12:  1,965,758 square feet or about 1000 new apartments--SO, in the short run, 1000 new apartments come from about a 2/3 buildout of existing vacant and surface parking
• Square footage of blue layer along Huron Street, 8 (south side), 10, and 12:  996,767.4-258,847 = 737,920 square feet of new or about 370 new apartments--height reduction, fine-tuning of historic district parcel base map, sensitivity to building over Sloan Plaza and so forth on that block of Huron Street.  Also placed with an eye to optimizing amount of new square footage and to reducing interaction with existing residential (but needs fine-tuning in that regard).
• Square footage of red layer,
• remaining the same as before
• Liberty--8 story buildings with a 3 story plinth:  462,626.76
• First and Ashley--4-6 story buildings with a 3 story plinth, 50/50 mix--two of the six story buildings are located on First; all others on Ashley:  385,128
• S. Main:  323,628
• altered:
• N. Main--half the buildings removed:  635,812
• S. University--new buildings added, at 8, 10, and 12 stories, consistent with setbacks of existing buildings, placed to optimize (somewhat) amount of new square footage.

923,546.68 - 83208.9017 = 840,337.7783

Colored virtual reality model
Grayscale virtual reality model
 
 

An additional color (green) might be used to separate, visually, the Ashley/First buildings from others.  Added colors may offer certain focused clarification of the model; however, they also fragment the visualization power of the model, as a whole.  There are merits and drawbacks; the needs of individual cases will determine how many colors to use.
 

Animations of selected viewpoints from the Virtual Reality files; please feel free to suggest other viewpoints to put into the VR files.

Sequence of animation frames:  gray is existing followed by taller scene of April 27 followed by shorter scene of May 10.

View from South Main

View from Main and William

View from Main and Washington

View from Main and Huron, looking North

View from Main and Huron, looking West

View from Main and Huron, looking East

View along Huron looking East from the west side

View along Huron looking West from State

View along S. University looking East from the Diag

View along S. University looking West from Washtenaw

Links to similar approaches:

http://depts.washington.edu/~uweek/archives/1998.08.AUG_06/_article2.html