CAS E
S T U DIES
3
S I N G L E FA M I LY R E S I D E N T I A L
U R BA N I N F I L L
M U LT I - FA M I LY R E S I D E N T I A L
C O M M E RC I A L
S I N G L E FA M I LY
RESIDENTIAL
SHEET
CFACT
ASE ST
U DY # 7
P C C O C E N T R A L C ATAW BA
20
City of Charlotte Cost Analysis
C AS E
S TUD I ES
SINGLE FAMILY
RESIDENTIAL
OV E RV I E W
FAC T S H E E T
C OS T S U M M A RY E S T I M AT E
EXISTING CONDITIONS
E X I S T I N G R E G U L AT I O N S
C A S E S T U DY # 1 U S D G
C A S E S T U DY # 2 M I N I M U M P E R M I T R E QU I R E M E N T S
C A S E S T U DY # 3 P C C O - C E N T R A L C ATAW BA
C A S E S T U DY # 4 P C C O - W E S T E R N C ATAW BA
C A S E S T U DY # 5 P C C O - YA D K I N
22
City of Charlotte Cost Analysis
S I N G L E FA M I LY
RESIDENTIAL
C AOVERVIEW
S E S T U DY # 7
PC C O C E N T R A L C ATAW BA
The project example for the single-family residential program is an approximately
project edges are provided to meet S.W.I.M., watershed and other requirements.
50-acre site located within the Lower Lake Wylie watershed overlay district. It
With the USDG analysis, the street pattern was changed to meet block size
is a wooded site with small pockets of isolated wetlands along a jurisdictional
and connectivity requirements. No additional storm water restrictions were
drainage feature along one boundary, and floodway limits and additional wetlands
imposed. Once the USDG were addressed, additional storm water controls were
along another. The approved project is part of a larger re-zoned master planned
incorporated with each subsequent design analysis, ranging from minimum
community with shared design elements, but was analyzed as a stand alone parcel
permit requirements to the more protective controls associated with the Yadkin-
for the purposes of this study. The project site was rezoned to an MX-1 zoning from
Southeast Catawba section of the PCCO. Each analysis carried with it the
an R-3 zoning classification. The program for the approved project is a slab-on-
appropriate controls, including storm water detention and runoff volume
grade, single family residential product that requires mass grading of the site. For
controls, water quality controls, including 85% TSS and 70% TP removal
comparative purposes, this program will be continued with each design analysis.
efficiency criteria, as well as corresponding buffers and undisturbed open
The land cost for this site was approximately $2.6 million.
space requirements. Infrastructure costs associated with these design tiers
ranged from $6.44 million for the current approved plan to $6.75 million for
This project example was redesigned for each design tier being analyzed with
the USDG design tier.
the Cost Analysis project, while keeping most of the approved development
assumptions constant. Namely the approved plan for the single-family development
Wet detention ponds were incorporated with each design as this BMP could
was redesigned to incorporate the USDG, Minimum Permit Requirements and the
effectively meet TSS, TP, detention and volume control requirements. Changes
Central Catawba, Western Catawba and the Yadkin-Southeast Catawba Districts
to the street and lot layout were necessary to capture increasing open space and
of the PCCO. The elements incorporated into the project as part of the USDG
buffer thresholds. As much as possible, open space was mitigated for on-site to
were brought forth with subsequent phases of design analyses. Cost estimates are
maximize lot yield, including platting, mitigated undisturbed open space at rear
carried forward with each design tier analyzed.
yards on private lots. Site grading remained fairly consistent, and actually tended
to decrease due to the requirement of undisturbed open space.
In summary, the existing project was developed to meet the current requirements
of the subdivision ordinance, the detention ordinance and the requirements
Staff reviewed the project development in relation to the draft Environmental
of the Lower Lake Wylie watershed overlay district. The project includes wet
Chapter of the City of Charlotte’s General Development Policies (GDP-E). The
detention ponds, designed to NCDENR standards, as well as provide storm
application of the USDG and the combination of undisturbed open space,
water detention for peak flows associated with the 2-year and 10-year design
mitigated open space and water quality protection provided by the PCCO would
storm events. Open space is provided to current standards and buffers, and
serve to meet the intent of the GDP-E.
23
S I N G L E FA M I LY
RESIDENTIAL
SHEET
CFACT
ASE ST
U DY # 7
P C C O C E N T R A L C ATAW BA
DESIGN CRITERIA
E X I S T I N G R E G U L AT I O N S
USDG
MIN PERMIT
REQUIREMENTS
PCCO - CENTRAL
PCCO - WESTERN
P C C O - YA D K I N
B L O C K FA C E L E N G T H ( P R E F E R R E D )
(AS APPROVED)
500’-600’
500’-600’
500’-600’
500’-600’
500’-600’
S I N G L E B L O C K FA C E L E N G T H ( M A X )
(AS APPROVED)
800’
800’
800’
800’
800’
N/A
2,800’
2,800’
2,800’
2,800’
2,800’
EXTERNAL CONNECTIONS
(AS APPROVED)
=BLOCK LENGTH
=BLOCK LENGTH
=BLOCK LENGTH
=BLOCK LENGTH
=BLOCK LENGTH
CREEK CROSSINGS
(AS APPROVED)
EVERY 1,300’ (APPROX)
EVERY 1,300’ (APPROX)
EVERY 1,300’ (APPROX)
EVERY 1,300’ (APPROX)
EVERY 1,300’ (APPROX)
U N D I S T U R B E D O P E N S PA C E *
NOT REQUIRED
NOT REQUIRED
NOT REQUIRED
17.5%
17.5%
17.5%
10%
10%
10%
10%
10%
10%
S W I M / WAT E R S H E D
SWIM / WATERSHED
SWIM / WATERSHED
PCCO
PCCO
PCCO
X
X
X
X
X
X
X
X
ELEMENTS
MAXIMUM BLOCK PERIMETER
T R E E S AV E *
BUFFERS
8 5 % T S S * R E M O VA L
7 0 % T P * R E M O VA L
DETENTION
VOLUME CONTROL
* See Appendix for definitions.
24
City of Charlotte Cost Analysis
X
X
X
X
X
X
X
X
X
X
S I N G L E FA M I LY
RESIDENTIAL
SHEET
CFACT
ASE ST
U DY # 7
PC C O C E N T R A L C ATAW BA
DEVELOPMENT SUMMARY
EXISTING
R E G U L AT I O N S
USDG
MIN PERMIT
REQUIREMENTS
PCCO - CENTRAL
PCCO - WESTERN
P C C O - YA D K I N
ZONING
MX-1
MX-1
MX-1
MX-1
MX-1
MX-1
SITE ACREAGE
51.9
51.9
51.9
51.9
51.9
51.9
55’ Lots
107
105
105
100
100
94
68’ Lots
64
63
63
62
62
62
LOTS (#)
171
168
168
162
162
156
3.29 DUA
3.24 DUA
3.24 DUA
3.10 DUA
3.10 DUA
3.00 DUA
7,247.3 LF
7,921.0 LF
7,921.0 LF
7,780.3 LF
7,780.3 LF
7,780.3 LF
44%
44%
44%
44%
44%
43%
O P E N S PA C E R E Q U I R E D * *
5.2 AC (10%)
5.2 AC (10%)
5.2 AC (10%)
5.2 AC (10%)
5.2 AC (10%)
5.2 AC (10%)
O P E N S PA C E P R O V I D E D
9.9 AC (19%)
10.5 AC (20.3%)
10.5 AC (20.3%)
13.1 AC (25.2%)
13.1 AC (25.2%)
13.9 AC (26.8%)
T R E E S AV E A R E A R E Q U I R E D * *
5.2 AC (10%)
5.2 AC (10%)
5.2 AC (10%)
5.2 AC (10%)
5.2 AC (10%)
5.2 AC (10%)
T R E E S AV E A R E A P R O V I D E D
6 AC (11.5%)
5.2 AC (10%)
5.2 AC (10%)
5.5 AC (10.6%)
5.5 AC (10.6%)
6.4 AC (12.3%)
NOT REQUIRED
NOT REQUIRED
NOT REQUIRED
9.08 AC (17.5%)
9.08 AC (17.5%)
9.08 AC (17.5%)
U N D I S T U R B E D O P E N S PA C E P R O V I D E D
5 AC (9.6%)
4.75 AC (9.1%)
4.75 AC (9.1%)
4.8 AC (9.5%)
4.8 AC (9.5%)
5.78 AC (11.1%)
M I T I G AT E D U N D I S T U R B E D O P E N S PA C E
NOT REQUIRED
NOT REQUIRED
NOT REQUIRED
6.35 AC
6.35 AC
4.3 AC
40,500 SF
40,500 SF
40,500 SF
79,100 SF
79,100 SF
79,300 SF
N/A
N/A
N/A
N/A
N/A
N/A
ELEMENTS
DWELLING UNIT PER ACRE (DUA)**
PUBLIC STREETS (LINEAR FEET)
% I M P E RV I O U S
U N D I S T U R B E D O P E N S PA C E R E Q U I R E D * *
BMP** WET POND
OFF-SITE IMPROVEMENTS
* All site design elements are applied as required to meet conditions of draft ordinances/policies based on specific conditions of site and in some cases, the original development plan. Some elements
and results would change with changing site conditions or slight variations in the development plan. Items specific to the approved plan were, where possible, held constant or varied only slightly to
meet draft policies.
** See Appendix for definitions.
25
26
City of Charlotte Cost Analysis
S I N G L E FA M I LY
RESIDENTIAL
COST ESTIMATE
C ASUMMARY
S E S T U DY # 7
PC C O C E N T R A L C ATAW BA
COST ESTIMATE SUMMARY
EXISTING
R E G U L AT I O N S
USDG
MIN PERMIT
REQUIREMENTS
PCCO - CENTRAL
PCCO - WESTERN
P C C O - YA D K I N
MX-1
MX-1
MX-1
MX-1
MX-1
MX-1
171
168
168
162
162
156
$37,840.00
$37,840.00
$37,840.00
$37,840.00
$37,840.00
$37,840.00
SITE GRADING
$1,591,125.00
$1,599,835.00
$1,599,835.00
$1,525,062.50
$1,525,062.50
$1,523,505.00
PAV I N G
$1,089,285.85
$1,347,596.56
$1,347,596.56
$1,323,659.33
$1,323,659.33
$1,323,659.33
STORM DRAINAGE
$1,485,126.66
$1,540,093.28
$1,540,093.28
$1,552,669.67
$1,552,669.67
$1,564,628.69
WET DETENTION PONDS
$100,914.01
$120,806.73
$120,806.73
$108,277.80
$108,277.80
$101,355.96
PRE DEVELOPMENT EROSION CONTROL
$109,827.25
$109,827.25
$109,827.25
$109,827.25
$109,827.25
$109,827.25
POST DEVELOPMENT EROSION CONTROL
$139,560.25
$139,560.25
$139,560.25
$139,560.25
$139,560.25
$139,560.25
$5,612.00
$5,612.00
$5,612.00
$5,612.00
$5,612.00
$5,612.00
$1,853,365.48
$1,820,850.30
$1,820,850.30
$1,744,981.53
$1,744,981.53
$1,679,951.17
N/R
N/R
N/R
$116,117.10
$116,117.10
$78,618.30
$26,425.00
$26,425.00
$26,425.00
$44,450.00
$44,450.00
$43,575.00
$6,439,081.50
$6,748,446.37
$6,748,446.37
$6,708,057.43
$6,708,057.43
$6,608,132.94
ELEMENTS
LOT YIELD
A L L O WA N C E S
L A N D S C A P I N G AT E N T RY
WAT E R & S A N I TA RY S E W E R
O P E N S PA C E M I T I G AT I O N
LITTORAL SHELF PLANTING
T O TA L
* All site design elements are applied as required to meet conditions of draft ordinances/policies based on specific conditions of site and in some cases, the original development plan. Some elements
and results would change with changing site conditions or slight variations in the development plan. Items specific to the approved plan were, where possible, held constant or varied only slightly to
meet draft policies.
** See Appendix for definitions.
* * * We t d e t e n t i o n p o n d c o s t d o e s n o t i n c l u d e g r a d i n g
27
S I N G L E FA M I LY
RESIDENTIAL
EXISTING
C
A S E S T U DY # 7
CONDITIONS
P C C O C E N T R A L C ATAW BA
1
3
CONTEXT MAP
BUFFERS AND WETLANDS
The site is one phase of a single family
master plan development. The site is located
near Lake Wylie, but will be studied in each
tier of watershed stipulation. The site was
studied as a stand alone, infill development
for the purposes of this study.
2
EXISTING TREES
Over 90% of the existing site was
covered with trees.
28
City of Charlotte Cost Analysis
A jurisdictional stream runs along the east of the
property with pocket wetlands. An intermittent
stream borders the west portion of the site. The
intermittent stream did not have a buffer
requirement under existing zoning.
4
SLOPE ANALYSIS
0-5%
5-10%
10+%
32 % of the existing topography has a slope of
10% or greater. 38% of the site has slopes within
the 5-10% and 30% of the site has slopes less
than 5%. A portion of the 0-5% slopes are located
in the floodplain and wetland area.
S I N G L E FA M I LY
RESIDENTIAL
EXISTING
C
A S E S T U DY # 7
CONDITIONS
PC C O C E N T R A L C ATAW BA
DEVELOPMENT SUMMARY
p
ZONING: MX-1
p
SITE ACREAGE: 51.9
p
55’ LOTS: 0
p
68’ LOTS: 0
p
T O TA L L O T S : 0
p
DUA: 0
p
PUBLIC STREETS (LF): 0
p
P E R C E N T I M P E RV I O U S : 0
p
O P E N S PA C E R E Q U I R E D ( A C ) : 0
p
O P E N S PA C E P R O V I D E D ( A C ) : 0
p
T R E E S AV E R E Q U I R E D ( A C ) : 0
p
T R E E S AV E P R O V I D E D ( A C ) : 0
p
U N D I S T U R B E D O P E N S PA C E R E Q U I R E D ( A C ) : 0
p
U N D I S T U R B E D O P E N S PA C E P R O V I D E D ( A C ) : 0
p
M I T I G AT E D U N D I S T U R B E D O P E N S PA C E ( A C ) : 0
p
BMP - WET PONDS: 0
p
OFF-SITE IMPROVEMENTS: 0
COST ESTIMATE SUMMARY
p
N/A
p
N/A
p
N/A
p
N/A
p
N/A
p
N/A
p
N/A
p
N/A
p
N/A
p
N/A
NOTES
This parcel is part of a master planned community of
a larger assembled tract of land. Many development
requirements were met as part of the master planned
project, but, for the purposes of this analysis, this tract
was analyzed as a stand-alone site.
29
S I N G L E FA M I LY
RESIDENTIAL
EXISTING
C A S E S T U DY # 7
REGULATIONS
P C C O C E N T R A L C ATAW BA
1
3
Undisturbed open space is not required under existing zoning. The approved plan is required to provide
10% open space, but the open space does not need
to be undisturbed. The approved plan provided 5
acres (9.6%) of undisturbed open space.
A 100-foot undisturbed buffer is required on the
stream on the eastern property boundary. No buffer is required on the intermittent stream on the
western property boundary. Wetland buffers were
provided per 404 permit standard conditions.
buffers and wetlands
undisturbed OPEN SPACE
2
tree save
Existing zoning is required to provide 10% tree
save. The approved plan provided slightly more
than the required 10% tree save.
30
City of Charlotte Cost Analysis
68’ LOTS
55’ LOTS
4
lot mix
Approved plan consists of two lot sizes: 68’ lots
and 55’ lots.
S I N G L E FA M I LY
RESIDENTIAL
EXISTING
C A S E S T U DY # 7
REGULATIONS
PC C O C E N T R A L C ATAW BA
DEVELOPMENT SUMMARY
p
ZONING: MX-1
p
SITE ACREAGE: 51.9
p
55’ LOTS: 107
p
68’ LOTS: 64
p
T O TA L L O T S : 1 7 1
p
DUA*: 3.29
p
PUBLIC STREETS (LF): 7,247.3 LF
p
P E R C E N T I M P E RV I O U S : 4 4 %
p
O P E N S PA C E R E Q U I R E D * ( A C ) : 5 . 2 A C ( 1 0 % )
p
O P E N S PA C E P R O V I D E D ( A C ) : 9 . 9 A C ( 1 9 % )
p
T R E E S AV E R E Q U I R E D * ( A C ) : 5 . 2 A C ( 1 0 % )
p
T R E E S AV E P R O V I D E D ( A C ) : 6 A C ( 1 1 . 5 % )
p
U N D I S T U R B E D O P E N S PA C E R E Q U I R E D ( A C ) : N / R
p
UNDISTURBED OPEN SPACE PROVIDED* (AC): 5 AC (9.6%)
p
M I T I G AT E D U N D I S T U R B E D O P E N S PA C E ( A C ) : N / R
p
BMP - WET PONDS: 40,500 SF
p
OFF-SITE IMPROVEMENTS: N/R
COST ESTIMATE SUMMARY
p
A L L O WA N C E S : $ 3 7 , 8 4 0 . 0 0
p
SITE GRADING: $1,591,125.00
p
PAV I N G : $ 1 , 0 8 9 , 2 8 5 . 8 5
p
STORM DRAINAGE: $1,485,126.66
p
WET DETENTION PONDS: $100,914.00
p
PRE DEVELOPMENT EROSION CONTROL: $109,827.25
p
POST DEVELOPMENT EROSION CONTROL: $139,560.25
p
L A N D S C A P I N G AT E N T RY: $ 5 , 6 1 2 . 0 0
p
WAT E R & S A N I TA RY S E W E R : $ 1 , 8 5 3 , 3 6 5 . 4 8
p
O P E N S PA C E M I T I G AT I O N : N / R
p
LITTORAL SHELF PLANTING: $26,425.00
p
T O TA L : $ 6 , 4 3 9 , 0 8 1 . 5 0
NOTES
The approved plan provided 171 lots at a DUA of 3.29.
The approved plan was developed maximizing developable
area. Open space provided was a product of tree save,
detention and buffer requirements.
* See Appendix for definitions.
31
S I N G L E FA M I LY
RESIDENTIAL
EXISTING
C A S E S T U DY # 7
REGULATIONS
P C C O C E N T R A L C ATAW BA
1
street sections
Approved plan used two different street
sections: Local limited residential and
local residential.
2
55’ lot typical
40’ local limited residential r.o.w. street section
Lot types with dimensions and setbacks remain
constant throughout single family case studies.
3
68’ lot typical
Lot types with dimensions and setbacks remain
constant throughout single family case studies.
45’ local residential r.o.w. street section
32
City of Charlotte Cost Analysis
S I N G L E FA M I LY
RESIDENTIAL
EXISTING
C A S E S T U DY # 7
REGULATIONS
PC C O C E N T R A L C ATAW BA
4
GRADING PLAN
The project was cleared and mass-graded to
meet the builder’s design of slab-on-grade home
product to minimum lot dimension.
33