Montgomery County UDA CalculationsCalculating UDA Size Requirements Based on 10 Year and 20 Year Population Estimates
Date: February 28, 2011
Locality: Montgomery County, VA
DRAFT Worksheet for Review Purposes - Revised to reflect 2010 Census Figures
Table 1 - Population Projections *
Locality 1990 2000 2010 2020 2030 2010-2020 2020-2030
Montgomery
County Current
VEC Projections
73,913 83,629 91,363 96,782 103,244
0.58% 0.65%
Montgomery
County Census
2010 Revised Total
73,913 83,629 94,392 99,991 106,667
Blacksburg 2010
Revised Total 34,922 39,573 42,620 45,148 48,162
Christiansburg
2010 Revised Total 15,402 16,947 21,041 22,289 23,777
Unincorporated
2010 Revised Total 23,589 27,109 30,731 32,554 34,727
Table 2A. Revised Population Projections Based on New 2010 Population Data
Locality 1990 2000 2010 2020 2030
Montgomery
County
Unincorporated
23,589 27,109 30,731 32,554 34,727
Table 2B - Assumptions Notes
Commercial SF per person: 60
Household Size: 2.3 Per County Comp Plan
Dwelling Unit/Acre: 4
FAR 0.4 Minimum UDA
Sq Ft/Acre @ .4 FAR 17,424
Table 3 - Future Housing and Commercial Square Footage Projections
10 Years 20 Years 10 Years 20 Years 10 years 20 Years
1,823 3,996 792 1,738 109,365 239,779
New Population New Housing Units Commercial Sq Feet
VEC AAGR **
VEC ‐State Demographer Projections will not
be available from VEC until December 2010,
following the release of the 2010 Census
figures. For the purposes of establishing
County and Town 10 and 20 year projections,
the most recent available VEC data was used to
derive an Average Annual Growth Rate.
Average annual average growth rates are
0.58% for the 2010‐2020 period and .65% for
the 2020‐2030 period.
The 2020 and 2030 projections shown for UDA
have been calculated by applying these
growth rates to the latest 2010 US Census base
year population for each locality.
Both Christiansburg and Blacksburg are now
required to adopt UDAs based on the percent
change in population from 2000‐2010. All
calculations for County UDA reflect only the
unincorporated portions of the County since
the UDA legislation requires that the
populations of any towns that are required to
adopt UDAs be EXCLUDED from the County
UDA population calculations.
The average household size of 2.3 persons per
household was used to calculate new housing
units. Commercial square feet needed to
accomodate new population was estimated at 60
SF of commercial space per person.
The following assumptions were used for the UDA
calculations.
Table 4 - UDA Requirements - Calculated at 4 DUA and FAR 0.4
Locality
10 years 20 Years 10 years 20 Years 10 years 20 Years
Montgomery
County
Unincorporated 198 434
6 14 204 448
Table 5 - Summary of UDA Area Requirement VALUES PRIOR TO 2010 CENSUS RECALCUATION
204 - Acres - 10 Year 426 - Acres - 10 Year
448 - Acres - 20 Year 841 - Acres - 20 Year
Residential Acres needed Employment Acreage Total Acreage Needed
Legislative Requirement: Identify sufficient acreage to meet 10 year but not
exceed 20 year requirements (see Table 4 using 4 DUA).
NOTE - FOR REFERENCE ONLY - THESE ARE THE OLD
REQUIREMENTS PRIOR TO THE NEW CENSUS DATA
VEC ‐State Demographer Projections will not
be available from VEC until December 2010,
following the release of the 2010 Census
figures. For the purposes of establishing
County and Town 10 and 20 year projections,
the most recent available VEC data was used to
derive an Average Annual Growth Rate.
Average annual average growth rates are
0.58% for the 2010‐2020 period and .65% for
the 2020‐2030 period.
The 2020 and 2030 projections shown for UDA
have been calculated by applying these
growth rates to the latest 2010 US Census base
year population for each locality.
Both Christiansburg and Blacksburg are now
required to adopt UDAs based on the percent
change in population from 2000‐2010. All
calculations for County UDA reflect only the
unincorporated portions of the County since
the UDA legislation requires that the
populations of any towns that are required to
adopt UDAs be EXCLUDED from the County
UDA population calculations.
The average household size of 2.3 persons per
household was used to calculate new housing
units. Commercial square feet needed to
accomodate new population was estimated at 60
SF of commercial space per person.
The following assumptions were used for the UDA
calculations.
The number of residential acres was calculated by
dividing new housing units by the minimum
density required in the legislation (4 DU/Acre).
Employment acreage was calculated by dividing
commercial square feet by the minimum intensity
required by the legislation (.4 FAR).