Three by Five Matrix

ALTERNATIVE VISUAL SCENARIOS FOR INCREASING RESIDENTIAL LAND USE IN THE DDA

THE BROAD GOALS ARE:

TO INCREASE THE NUMBER OF RESIDENTIAL UNITS IN THE DOWNTOWN WITHOUT DIMINISHING THE QUALITY OF LIFE FOR RESIDENTS OF ANN ARBOR, IN THE DOWNTOWN AND ELSEWHERE IN THE CITY.
TO INCREASE THE NUMBER OF RESIDENTIAL UNITS WITHIN THE CITY TO SAVE GREEN SPACE OUTSIDE THE CITY (IN SUPPORT OF POLITICAL AND OTHER EFFORTS TO WORK WITH SURROUNDING MUNICIPALITIES)
TO INCREASE OPPORTUNITY FOR PEOPLE WHO WORK IN THE CITY TO LIVE IN THE CITY

The following 3D models show alternative visual patterns for possible DDA increases in square footage. In selecting parcels as targets for further possible development, the following categories were excluded, using the following locational principles:

Parcels in current historic districts
Parcels in the floodway of Allen Creek
Parcels whose centroid lay in the floodplain of Allen Creek
Parcels containing churches
Parcels belonging to the University of Michigan
In the first and third rows, parcels containing parking structures and parcels designated as public land (outside the University).

The goal is to allow for the construction of 2500 new residential units of about 1000 square feet each. A target of 5,000,000 new square feet should ensure that capability (2.5 million inside apartments and the rest devoted to building infrastructure, parking, commercial, and other as required by various needs).
If each apartment translates to a savings of one-quarter of an acre of green space, then the target of 2500 apartments translates to a savings of 625 acres of land or close to one section (640 acres).
Click on each image to link to a virtual reality file; thus, the viewer may consider the model from various vantage points (first install Cosmo Player, a free download, in your browser). In the lower left hand corner, pull down the menu where it says "default"--choose one of the other options. These offer consistent navigation markers that will automatically fly you to selected locations so you can make comparisons among models.
The estimated square footage that is new in each model is shown in the caption below the model.
The model on the left is a model of the existing downtown and of University of Michigan buildings within the boundary of the DDA. Broader context would create different views. These views are of the DDA, only.
All models are draped over a topographic surface of the DDA formed from city contour maps (5 foot contour interval).
A point source of light was set in the south at 42.28 degrees (latitude of Ann Arbor). This position represents the sun position at equinox. The setting of the light source does not, however, offer models of shadows.

Total estimated square footage within model of existing buildings: 7,469,852 square feet.

SPATIAL PATTERN DRIVES ZONING. Model on the left shows existing buildings in the DDA. Key streets are marked with vertical labels; the last letter in the street name rests on the appropriate street. The color models highlight new buildings against the gray, existing model. The all-gray versions of the color models allow the viewer to consider the entire proposed downtown and to visualize massing patterns of the new buildings with the old. The model in this row has the widest variety in height (most 3D texture), much square footage coming from construction proposed for already-vacant lands, and lowest height changes in existing residential sections of the DDA (along First and Ashley). Zoning will be adjusted to fit with buildout. Massing and 3D spatial pattern drive zoning.

The four scenes to the right are based on one set of ideas:

Yellow buildings are built on lots that are now vacant or that now contain surface parking. All yellow construction represents new square footage.

Towers:

are built on 90 by 90 foot bases at heights of 9, 12, and 15 stories. Placement--taller placed at lower elevation within parameters for spacing between towers.
project upward from 3 story decks.

Other yellow buildings on parcels not large enough to hold a tower have 10 foot side setbacks, 0 foot front setbacks, and 40 foot rear setbacks. They have 20 foot upper story setbacks above the third floor.

Blue buildings are built along Huron Street, at mixed heights of 9, 12, and 15 stories. The placement pattern is arbitrary. New square footage is determined by subtracting existing square footage on the target parcels from the modeled square footage. Setbacks are as above, with the guiding principle that a grand boulevard has uniform front setbacks and that existing patterns of front setbacks determine that uniformity locally. Thus,

Buildings to the east of Division have 20 foot front setbacks
Buildings to the west of Division have 0 foot front setbacks and 20 foot upper story setbacks above the third story.

Red buildings are built along

Liberty, with setbacks as above including 20 foot upper story setbacks above the third floor. Maximum height is 8 stories
First and Ashley, with setbacks as above including 20 foot upper story setbacks above the third floor. Maximum heights: half at six stories, half at four stories.
South Main, with setbacks as above including 20 foot upper story setbacks above the third floor. Maximum height is as currently zoned.
Not in these views, but in the linked view: North Main, outside the DDA, east of N. Main. River-view apartments, set back at 20 feet from N. Main with building footprint scaled by the golden ratio within the parcel. All square footage in this category is also considered new square footage.

Total available new square footage using these principles is: yellow, 3,149,919; blue, 1,930,283; red DDA, 2,260,922; red North Main, 1,674,625. These values add to: 10,690,374. The scenes to the right choose about half the buildings from each category to approximate 5,000,000 new square feet.

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Alternative 1--color. Total estimated square footage within this model is about 5 million square feet of new space with most coming from the yellow buildings (about half of 3+ million in the yellow and about half of 2- in the blue). Model uses widely-spaced tall buildings to keep increases in height along First and Ashley quite modest. About one half million new square feet come from North Main (out of this picture). This model has the widest variety in height (most 3D texture) and lowest height changes in existing residential sections of the DDA.

Alternative 2--color. Total estimated square footage within this model is about 5 million square feet of new space with most coming from the yellow buildings (about half of 3+ million in the yellow and about half of 2- in the blue). Model uses widely-spaced tall buildings to keep increases in height along First and Ashley quite modest. About one half million new square feet come from North Main (out of this picture). This model has the widest variety in height (most 3D texture) and lowest height changes in existing residential sections of the DDA.

Alternative 1--gray. Model uses widely-spaced tall buildings to keep increases in height along First and Ashley quite modest. About one half million new square feet come from North Main (out of this picture). This model has the widest variety in height (most 3D texture) and lowest height changes in existing residential sections of the DDA.

Alternative 2--gray. Model uses widely-spaced tall buildings to keep increases in height along First and Ashley quite modest. About one half million new square feet come from North Main (out of this picture). This model has the widest variety in height (most 3D texture) and lowest height changes in existing residential sections of the DDA.

Total estimated square footage within model of existing buildings: 7,469,852 square feet.

ZONING DRIVES SPATIAL PATTERN Model on the left shows existing buildings in the DDA. Key streets are marked with vertical labels; the last letter in the street name rests on the appropriate street. The color models highlight new buildings against the gray, existing model. The all-gray versions of the color models allow the viewer to consider the entire proposed downtown and to visualize massing patterns of the new buildings with the old. The model in this row has much square footage coming from construction proposed for already-vacant lands, the widest variety in land use category included as an option, and the largest total amount of square footage that could come into the system. It is based on a new zoning plan conceived in advance of building models. Link to detailed document involving zoning. One category to note is an "Opportunity Zone" bounded by William and Huron, State and First, roughly. Zoning drives spatial pattern.

The four scenes to the right are based on interpreting the linked zoning document in terms of the categories above, in an effort to create comparable models. Within that zoning context, the color categories translate as follows.

Yellow buildings are built on lots that are now vacant or that now contain surface parking. All yellow construction represents new square footage. The same setbacks are used for these buildings are are used in the model set above, including 20 foot upper story setbacks above the third floor.
Blue buildings are built

along Huron Street at a maximum height of 8 stories on the south side and 12 stories on the north side (to let sunlight into the corridor). These buildings are part of a new "Tall" zone that is split into two sections. See the linked document for detail.

Buildings to the east of Division have 20 foot front setbacks
Buildings to the west of Division have 0 foot front setbacks and 20 foot upper story setbacks above the third story.

in parcels

within the Opportunity Zone that are currently zoned Parking or Public Land (not UM) at a maximum of 12 stories east of Main and 8 stories west of Main.
outside the Opportunity Zone at nearby zoning.

Red buildings are built along

Liberty, with setbacks as above including 20 foot upper story setbacks above the third floor. Maximum height is 8 stories
First and Ashley, with setbacks as above including 20 foot upper story setbacks above the third floor. Maximum heights: at eight stories in the Opportunity Zone and elsewhere as per zoning prescribed by new zoning (never more than 8).
South Main, with setbacks as above including 20 foot upper story setbacks above the third floor. Maximum height is as zoned.

Total available new square footage using these principles is: yellow, 3,260,010; Huron blue, 1,661,403; red DDA, 2,791,216; blue P and PL, 4,979,213. The sum of all categories except the P and Pl value is 7,712,629 square feet; take also 2,287,31 from the 4,979,213 in P and PL to add to 10,000,000. The scenes to the right choose about half the buildings from each category except P and PL. From the latter category they show about one-quarter of those. Altogether, these models roughly approximate 5,000,000 new square feet.

Alternative 1--color. Total estimated square footage within this model is about 5 million square feet of new space with most coming from the yellow buildings (about half of 3+ million in the yellow and about half of 2- in the blue). Buildings containing large amounts of square footage often are more massive, laterally, in appearance than are those above (which gain mass through height rather than breadth).

Alternative 2--color. Total estimated square footage within this model is about 5 million square feet of new space with most coming from the yellow buildings (about half of 3+ million in the yellow and about half of 2- in the blue). Buildings containing large amounts of square footage often are more massive, laterally, in appearance than are those above (which gain mass through height rather than breadth).

Alternative 1--gray. Total estimated square footage within this model is about 5 million square feet of new space with most coming from the yellow buildings (about half of 3+ million in the yellow and about half of 2- in the blue). Buildings containing large amounts of square footage often are more massive, laterally, in appearance than are those above (which gain mass through height rather than breadth).

Alternative 2--gray. Total estimated square footage within this model is about 5 million square feet of new space with most coming from the yellow buildings (about half of 3+ million in the yellow and about half of 2- in the blue). Buildings containing large amounts of square footage often are more massive, laterally, in appearance than are those above (which gain mass through height rather than breadth).

Total estimated square footage within model of existing buildings: 7,469,852 square feet.

CURRENT ZONING AND SPATIAL PATTERN: FULL BUILDOUT Model on the left shows existing buildings in the DDA. Key streets are marked with vertical labels; the last letter in the street name rests on the appropriate street. The color models highlight new buildings against the gray, existing model. The all-gray versions of the color models allow the viewer to consider the entire proposed downtown and to visualize massing patterns of the new buildings with the old. The model in this row is based on the current zoning and the current spatial pattern.

These two alternatives show a mixture of construction categories with yellow buildings on vacant and surface parking lots, as above, and blue buildings along Huron Street, as above. In both cases, height is governed by current zoning with premiums (in five zoning categories). The yellow and blue represent total buildout in those categories. The red is about 2/3 builtout in those categories allowing premiums. Many more parcels must see substantial change in order to achieve the 5,000,000 mark. Full buildout is never a reality.

Uniformity in spatial pattern is strong; 3D texture is weakest in this row of models. Total available new square footage using these principles is: yellow, 2,375,123; blue, 769,473; red, 2,909720.

Alternative 1--color.

Alternative 2--color.

Alternative 1--gray.

Alternative 2--gray.

NOTE:

the software will calculate square footage accurately, once it has information. The level of accuracy of the basic information is not known. Further, as changes occur in the models, in response to input from viewers, corresponding square footage information display may not keep pace with the mapped changes.
the models presented above are but two of each type chosen from an infinite number of choices available within each fully built out mode.

Sandra L. Arlinghaus

Solstice: An Electronic Journal of Geography and Mathematics, Institute of Mathematical Geography, Ann Arbor, Michigan.
Volume XV, Number 1.
http://www.InstituteOfMathematicalGeography.org/