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Thursday, May 26, 2011

THE LEADERSHIP POTENTIAL of INTENSITY MEASUREMENT

            Development displaces project open space with building mass and pavement to produce intensity. It’s so obvious it’s an axiom, but it’s been difficult to assess because accurate measurement of intensity has been missing. This has prevented us from leading it in the right direction. When total development area TDA and open space S are measured as multiples of the buildable land available BLA, however, their relationship determines the level of intensity INT involved. This relationship is defined by Equation 1, which was discussed in detail in my blog essay, “The Nature of Intensity”. The equation defines intensity so it can be measured during context evaluation, but our future ability to live within sustainable geographic limits will depend on our ability to forecast its presence and choose among options. 
Equation 1:   INT = TDA / S

            Table 1 presents the potential range of intensity options within our built environment using Equation 1, and is also repeated from “The Nature of Intensity”. These calculations have nothing to do with form, function and appearance, which is similar to the fact that Archimedes’ shape, anatomy and appearance had nothing to do with his discovery of mass as he displaced water in an over-filled tub. Equation 1 also has nothing to do with the activities inside a building. From a shelter intensity standpoint, all buildings and pavement are the same. The same intensity value will produce the same open space displacement. The activities sheltered within will produce additional levels of traffic and utility demand. Since movement, public open space and life support systems serve shelter however, shelter intensity protects activity that magnifies intensity in any neighborhood. In other words, urban form is an expression of physical intensity that is magnified by social activity, and supported by economic yield with corresponding psychological implications.  

We have not adequately defined intensity to efficiently use the development capacity of land within sustainable limits. Do not leap to the conclusion that I’m proposing a universal lifestyle of high intensity to accommodate population growth, however. I’m proposing that we must understand intensity before we can offer a range of options to shelter growth within natural limits. This means that we must be able to understand development capacity and intensity before growth takes away our options.  

TABLE 1
DEVELOPMENT INTENSITY TABLE 

NOTE:










BLA=
buildable land area




S=
project open space







GBA=
total building area including all floors


BCA=
total building cover area (footprint)
TPC=
total pavement cover


TDC=
development cover area







TDA=
total development area







TDC=
BCA + TPC








TDA=
TBA + TPC












TDC and S as fraction of BLA


S
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.001
TDC
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.999











TDA or GBA as


INTENSITY as a multiple of BLA




 multiple


NOTE: Values above stair step only  apply to GBA intensity since TDA + S must be >= 1
of BLA


GBA + S can be  < 1 since total pavement cover TPC is not included











0.10
0.11
0.13
0.14
0.17
0.20
0.25
0.33
0.50
1.0
100
0.20
0.22
0.25
0.29
0.33
0.40
0.50
0.67
1.00
2.0
200
0.30
0.33
0.38
0.43
0.50
0.60
0.75
1.00
1.50
3.0
300
0.40
0.44
0.50
0.57
0.67
0.80
1.00
1.33
2.00
4.0
400
0.50
0.56
0.63
0.71
0.83
1.00
1.25
1.67
2.50
5.0
500
0.60
0.67
0.75
0.86
1.00
1.20
1.50
2.00
3.00
6.0
600
0.70
0.78
0.88
1.00
1.17
1.40
1.75
2.33
3.50
7.0
700
0.80
0.89
1.00
1.14
1.33
1.60
2.00
2.67
4.00
8.0
800
0.90
1.00
1.13
1.29
1.50
1.80
2.25
3.00
4.50
9.00
900
1.00
1.11
1.25
1.43
1.67
2.00
2.50
3.33
5.00
10.0
1,000
1.25
1.39
1.56
1.79
2.08
2.50
3.13
4.17
6.25
12.5
1,250
1.50
1.67
1.88
2.14
2.50
3.00
3.75
5.00
7.50
15.0
1,500
1.60
1.78
2.00
2.29
2.67
3.20
4.00
5.33
8.00
16.0
1,600
1.70
1.89
2.13
2.43
2.83
3.40
4.25
5.67
8.50
17.0
1,700
1.75
1.94
2.19
2.50
2.92
3.50
4.38
5.83
8.75
17.5
1,750
2.00
2.22
2.50
2.86
3.33
4.00
5.00
6.67
10.00
20.0
2,000
3.00
3.33
3.75
4.29
5.00
6.00
7.50
10.00
15.00
30.0
3,000
4.00
4.44
5.00
5.71
6.67
8.00
10.00
13.33
20.00
40.0
4,000
5.00
5.56
6.25
7.14
8.33
10.00
12.50
16.67
25.00
50.0
5,000
6.00
6.67
7.50
8.57
10.00
12.00
15.00
20.00
30.00
60.0
6,000
7.00
7.78
8.75
10.00
11.67
14.00
17.50
23.33
35.00
70.0
7,000
8.00
8.89
10.00
11.43
13.33
16.00
20.00
26.67
40.00
80.0
8,000
9.00
10.00
11.25
12.86
15.00
18.00
22.50
30.00
45.00
90.0
9,000
10.00
11.11
12.50
14.29
16.67
20.00
25.00
33.33
50.00
100.0
10,000
50.00
55.56
62.50
71.43
83.33
100.00
125.00
166.67
250.00
500.0
50,000
100.00
111.11
125.00
142.86
166.67
200.00
250.00
333.33
500.00
1,000.0
100,000
200.00
222.22
250.00
285.71
333.33
400.00
500.00
666.67
1,000.00
2,000.0
200,000
400.00
444.44
500.00
571.43
666.67
800.00
1,000.00
1,333.33
2,000.00
4,000.0
400,000
500.00
555.56
625.00
714.29
833.33
1,000.00
1,250.00
1,666.67
2,500.00
5,000.0
500,000













             It’s easy to measure and evaluate total development area TDA in an existing context, but more difficult to forecast this quantity during planning evaluation. When making predictions, a design category must be chosen and values must be entered in its design specification template. When complete, these values are used by embedded equations to forecast the total development area implied and the intensity represented. There are forty forecast model choices, and the detail of their design specification templates produce total development area predictions. These can be indexed by the intensity calculated with Equation 1. Relating design specifications to intensity will improve our ability to shelter growing populations within sustainable limits, since intensity is a benchmark that can lead project performance and assemble results within sustainable limits defined by the science of others.  

            The RG1L forecast model in Table 2 makes the case that all design specifications produce a discrete level of intensity, and that the combination of design specifications and intensity benchmarks can become a leadership language for city design and architecture. The RG1 design category applies to multi-family residential buildings using grade parking lots around, but not under, the building. The suffix L means that gross land area must be given. The design specification template for RG1L is quite different from the CG1L template used in “The Nature of Intensity”, since it includes characteristics that make multi-family residential buildings a unique design category. The design specification values entered, however, produce forecasts that predict the relationship of building mass and pavement to open space. The component areas of this relationship are predicted in The Planning Forecast Table. Total development area TDA is simply the sum of these pieces for each building height option noted. In other words, TDA = GBA+PLA+RDA+LDA+MSP, or total development area equals the sum of gross building area, parking area, public right-of-way area, loading area and miscellaneous pavement area for each building height option (f) noted. The relationship between the TDA forecast and the open space S specified in the design specification template determines the intensity INT forecast for each building height option (f). 

            The design specification template in forecast model RG1L is quite involved because of its dwelling unit mix options; and it should be clear that a nearly infinite number of options is possible, since a change in one or more design specification values produces a new forecast. All of these options, however, will produce levels of intensity that fall within the universal table of intensity presented in Table 1. The specific INT values represented by this example are included in the right-hand column of Table 2.  

TABLE 2
MULTI-FAMILY REIDENTIAL INTENSITY:  AGG = 1,000

DESIGN SPECIFICATION












Given:

Gross Land Area in AC

4.000

174,240
SF
Public/ private right-of-way & paved easements

0.000
W as fraction of GLA
0
SF

Net Land Area

4.000
NLA in acres

174,240
SF
Facilities and features to remain as fraction of GLA

0.000

0
SF
Gross Land Area Reduction
X=
0.000
fraction of GLA

0
SF
Buildable Land Area Remaining
BLA=
4.000
acres

174,240
SF
Est. gross pkg. lot area per pkg. space in SF
s =
350
ENTER ZERO IF NO PARKING REQUIRED

Parking lot spaces planned or required per dwelling unit
u=
1.5
ENTER ZERO IF NO PARKING REQUIRED

Garage parking spaces planned or required per dwelling unit
Gn=
0
ENTER ZERO IF NO PARKING REQUIRED

Gross building area per garage space
Ga=
0
ENTER ZERO IF NO PARKING REQUIRED

No. of loading spaces
l =
0




Gross area per loading space
b =
0
SF

0
SF
Project Open Space as fraction of BLA
S=
0.300


52,272
SF
Private Driveways as fraction of BLA
R=
0.030


5,227
SF
Misc. Pavement as fraction of BLA
M=
0.020


3,485
SF
Loading area as fraction of BLA
L=
0.000
0
R+M+L=
8,712
SF
Total Site Support Areas as a fraction of BLA
Su=
0.350


60,984
SF
Core development area as fraction of BLA
C=
0.650
C=Su must = 1

113,256
SF
Building efficiency as percentage of GBA
Be=
0.850
must have a value >0 entered



Bldg. support as fraction of GBA
Bu=
0.150
Be + Bu must = 1



Dwelling Unit Mix Table:
NOTE: The Dwelling Unit Mix table requires that (Be) above contain a value greater than zero. 
DU

GDA

CDA=GDA/Be

MIX


PDA = (CDA)MIX

dwelling unit type

gross du area

comprehensive du area - unless override, fill in (Be)

du mix


Pro-rated du area

EFF

350

412

0%


0

1 BR

500

588

30%


176

2 BR

1,000

1,176

70%


824

3 BR

1,200

1,412

0%


0

4 BR

1,400

1,647

0%


0


Aggregate Avg. Dwelling Unit Area
 (AGG) =
1,000


GBA sf per parking space
a=
667

PLANNING FORECAST
 Enter zero in the adjacent box unless you wish to override the AGG value calculated above

0

no. of floors


density per
dwelling units
pkg. lot spaces
parking lot area
gross bldg area
footprint
total
intensity
FLR

CORE
dBA
NDU
NPS
PLA
GBA
BCA
TDA
INT


min. area for BCG & PLA
buildable acre



no garages
no garages
dev. area
TDA / S
1.00

113,256
18.57
74.3
111.4
38,990
74,266
74,266
121,968
2.33
2.00


27.62
110.5
165.7
58,009
110,494
55,247
177,215
3.39
3.00


32.99
131.9
197.9
69,273
131,949
43,983
209,934
4.02
4.00

NOTE:
36.53
146.1
219.2
76,722
146,137
36,534
231,571
4.43
5.00

Be aware
39.05
156.2
234.3
82,013
156,215
31,243
246,940
4.72
6.00

when BCA
40.94
163.7
245.6
85,965
163,744
27,291
258,421
4.94
7.00

becomes too
42.40
169.6
254.4
89,030
169,581
24,226
267,323
5.11
8.00

small to be
43.56
174.2
261.4
91,476
174,240
21,780
274,428
5.25
9.00

feasible
44.51
178.0
267.1
93,473
178,044
19,783
280,230
5.36
10.00


45.30
181.2
271.8
95,135
181,210
18,121
285,057
5.45
11.00


45.97
183.9
275.8
96,539
183,884
16,717
289,136
5.53
12.00


46.54
186.2
279.3
97,741
186,174
15,515
292,628
5.60
13.00


47.04
188.2
282.2
98,782
188,157
14,474
295,651
5.66
14.00


47.47
189.9
284.8
99,692
189,890
13,564
298,295
5.71












NOTE: When open space and parking requirements remain constant, development capacity declines rapidly above 5 floors.


            The point is that buildings shelter a wide range of activities; but their appearance, construction and purpose have confused the issue of sprawl and sustainability. They all provide shelter and produce levels of intensity that reflect the design specification values chosen. These intensity options displace open space. Forecasts define the options available to shelter growing populations, but not all are desirable. Existing context evaluation will provide information for comparison and evaluation. Decisions will be defined with design specifications and intensity measurements that have strategic leadership potential. The architecture that emerges will respond to the policy decisions adopted. 

Growing populations ensure that a sprawling pattern of random construction on plentiful land cannot continue. We are expected to take the issue seriously as stewards who have not yet recognized their planning responsibility. Cities are simply architecture on a grand scale. If architectural design does not express this new level of land use awareness, then we will not be able to lead cities toward a sustainable future – no matter how environmentally conscious and energy efficient we become. In this scenario, sprawl consumes the land while public health and safety exacerbate the problem and increase a decline in our quality of life. 

Table 2 predicts physical intensity as a foundation for social and economic activity based on the design specification values entered. I won’t belabor the point since I hope I have made these relationships clear, but the underling message is that we can predict intensity before we build, which means that leaders can plan and design shelter options for the activities of growing populations within sustainable limits, but we need the commitment, research and authority to begin.   

AUTHOR NOTE: The forecast models displayed are part of a software collection entitled, “Development Capacity Evaluation” that is included with the book, Land Development Calculations, ed. 2, McGraw-Hill, 2010. More information about the book and software are included in the “About Me” section of this blog.

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