This layer covers the Rural and Transitional place types in Loudoun County, as well as the Joint Land Management Areas that naturally fall within them. It does not cover areas within incorporated towns.

Workflow:

Several intermediate steps were taken to create the layer:

Used an intersect to add zoning data to the Loudoun parcels layer (intersected the downloaded parcels layer with the online zoning map) to make Parcels_Zoning

Exported a manual selection of the rural and transitional place type areas to a new feature layer (West_Loudoun)

Used Select by Location (set to Intersect) to select the parcels in Parcels_Zoning that intersect with the new West_Loudoun layer and then exported them as a new feature class (WLoudoun_Parcels)

Used the Pairwise Clip tool and WLoudoun_Parcels to extract the area of interest from the Loudoun_Conservation_Easements layer to make the WLoudoun_Easements layer

Also used the Pairwise Clip tool and WLoudoun_Parcels to extract the area of interest from the conslands layer (a dataset showing Virginia lands managed for conservation; see Credits) to make the WLoudoun_Managed layer

Also used the Pairwise Clip tool and WLoudoun_Parcels to extract the area of interest from the Loudoun_County_Owned_and_Leased layer--which had a definition query active to only allow property the county owns--to create the WLoudoun_CountyProp layer

Used the Identity tool to load the information in the WLoudoun_Easements layer into the WLoudoun_Parcels layer, creating the WLP2 layer

Used the Identity tool to load the information in the WLoudoun_Managed layer into the WLP2 layer, creating the WLP3 layer

Used the Identity tool to load the information in the WLoudoun_CountyProp layer into the WLP3 layer, creating the WLoudoun_Lots layer

After the layer was created, this is the process I used to work within it:

Created a new field (PieceAcr) to store the sizes of the pieces; populated it with Calculate Geometry--US Survey Acres, Geodesic Area, and the same coordinate system as the original Loudoun Parcels layer from Loudoun County

Created several new fields to store zoning information:

basedensity: size of a normally-divided lot

minacres: the smallest beginning parcel for a cluster subdivision

openlot: the size of conservation lot needed for a cluster subdivision

clusterdensity: the mean lot size for a cluster subdivision

maxlots: where the outputs per property for the maximum lots it can be divided into go

Notes: The openlot factor only matters in A10 and A3 zonings; otherwise, clusterdensity accounts for the open space, as lots can be small enough to keep the mean density, even though some are large

All are Double data type except Openlot, which is Short

Populate all the fields for zonings that include all of them, even though they may be treated differently

Do not fill in irrelevant fields (don't just copy the base density, or include anything under openlot if it's no different from other lots)

For zonings without a minimum lot size, make it 1/10 acre

The coding for the agricultural zonings is as follows:

#For A-10 and A-3 zoning codes

def getlots(totalacres, basedensity, minacres, openlot, clusterdensity):

if totalacres >= minacres:

base = int(totalacres/basedensity)

if int((totalacres-openlot)) <= 0.15*(totalacres):

cluster = int((totalacres-openlot)/clusterdensity)+1

else: cluster = int((0.15*totalacres)/clusterdensity)+1

if base >= cluster:

num = base

else:

num = cluster

else:

num = int(totalacres/basedensity)

return num

#For AR-1 and AR-2 zoning codes

def getlots(totalacres, minacres, cluster):

if totalacres >= minacres:

num = int(totalacres/cluster)

else:

num = 1

return num

Then used Select by Attributes to go through the pieces by zone and fill in the information, calculating maxlots along the way

Next created a new field, lotscap, to put in the actual cap on lots per parcel

Also created another new field, status, which tells the conservation status of a property with a domain:

1: Conservation (part of the Managed Areas list from the Virginia Department of Natural Resources)

2: Cons Easement (in the Loudoun County conservation easements layer)

3: County-owned (in the Loudoun County county properties layer)

4: Unprotected