Brief powerpoint providing real world example of the linkage between density and sustainability . .. Using Austin's real growth numbers . . .

1. Housing . . . Living Urban versus Suburban . . .
September 2012
Terry Mitchell
July, 2011

2. Suburban Example . . .
About 240 Net Acres
600 Units
300 Park Acres

3. Downtown Sample
1033 Units
24.10 Acres
Urban housing . . .

4. Consequences of Suburban – Sprawl
• How do we want to grow?

5. Let’s Look at Austin
• Austin (metro) is expected to grow 580,000
people over the next 10 years . . .
• Austin grew 67,000 in 2011.
• Many of our development regulations are
focused on “low density”, “preservation of the
environment” . . .
• “Density” is a bad word . . . (It should be your
best friend . . . )

6. What will Austin look like in 10 years?
• 580,000 new residents . . . At 2.6 people per
housing unit, means 223,077 new housing
units will be needed . . .

7. Suburban Density of 3 Units/Acre
• At a suburban density of 3 units per acre, we
will need 74,359 acres of land to house just
our population growth over the next 10 years.
• . . . or 116 square miles. . . .

8. Townhome Density of 10 Units/Acre
• At a townhome density of 10 units per
acre, we will need 22,308 acres of land to
house just our population growth over the
next 10 years.
• . . . Or 35 square miles. . . .

9. Downtown Density of 200 Units/Acre
»At a downtown density of 200 units per
acre, we will need 1,115 acres of land to
house just our population growth over
the next 10 years.
». . . Or 1.7 square miles. . . .

10. What Differing Densities Look Like

11. Density Helps Affordability

12. What does the differing forms of
development mean for the City?
• If you take the roads – and utilities under the
roads – that must be built to house these
folks, over the next 10 years (for Austin), you
will be building enough roads to get you to:
• At 3 units per acre, almost to Seattle, WA.
• At 10 units per acre, almost to Oxford, MS.
• At 200 units per acre, almost to San
Marcos, Tx.

14. Sustainability
Comparison of Downtown High Rise And Suburban Development
*This Chart compares the "environmental footprint" of a downtown high rise community with (i) a similarly priced luxury suburban community, (ii) a typical suburban single family community,
and (iii) a lower density condominium project, all with a similar number of units.
Urban/Suburban Typical Suburban Similarly Priced
Urban Condo Project Condo Project Single Family Project One Acre Lot Project
Number of Units 200 200 200 200
Acreage consumed for project Under 3/4 of an acre approximately 20 acres Between 57 and 70 acres 220 to 230 acres
(approximately 10 units per acre (between app. 3 and 3.5 units (approximately one acre lots
with roads and drainage) per acre with roads and drainage) with roads and drainage)
Impervious Coverage
Percentage of Total Project 100% 55 to 60% 45% 15 to 45%
Total Acres of IC 3/4 of an acre 11 to 12 acres 26 to 32 acres 29 to 87 acres
Length of Streets and Utility Lines 334 feet app. 1900 feet 1.5 to 2 miles 4 to 5 miles
Internal to the Project
Landscape Water Usage Zero 6,800,000 gal/year 15,600,000 gal/year 40,000,000 gal/year
(Landscaping irrigated with (Based on actual 10 unit per acre (Typical standard lot irrigates (Typical one acre lot irrigates at least
rain water collection system condo project, including approximately 6,500 gallons 10,000 s.f. resulting in
and A/C condensation initial establishment of landscaping. or 78,000 gallons per year 200,000 per year of potable
collection system.) 2,833 gal/mo. Or 34,000 gal/yr.) of potable water for irrigation.) water used to irrigate landscaping.)
Electricity Usage $10 to $60 per month app. $50 to $200 or more app. $100 to $300/mo. or more $250 to $450 per month
(Energy efficient design; green (Usage is less with smaller (This usage will vary greatly (Typical higher usage
building, smaller size; using City size homes and common walls. depending on the size of the home with larger size housing and separate
chilled water system for A/C.) Typically less than single family.) and multiple A/C units per home.) and multiple A/C units per home.)
Taxable Value Per Acre Over $80 million to Depends on location and Approximately $700,000 to Approximately $1 million per acre
$150 million per acre, value of units. Range is from $1,225,000 per acre (assuming an average home value
depending on value of app. $2,000,000 per acre to (assuming an average home value of approximately $1 million per home)
units.) (unit values from $200k/unit) of approximately $200,000 per home)
Percentage of Taxes Used to Provide about 10% to 20% Taxes may pay for services Taxes do not pay for services Taxes do not pay for services
City Services to Community (Mayor's Will Wynn statement that needed for Community needed for Community needed for Community
downtown buildings need as tax base is higher and
only 20% of taxes to maintenance obligations are
provide City Services) much lower.
10/16/2009