Looking at Parcel-Level Data

To better understand both the Future Land Use Map and the counterfactual of no change to the current land use, we took a look at parcel-level data from the Charlottesville’s Open Data Portal. We need to preface what we found by saying that while the portal itself is an excellent project — it is great for citizens to be able to dive into this data — the data that NDS provides to the ODP team is quite “dirty” and has a lot of organizational and definitional problems. Therefore, these maps should be treated with a certain amount of circumspection. We are including (below) a plot-level spreadsheet and we encourage readers to take a look at plots in their neighborhoods and let us know if there are plots that should not be included or that are missing.

We wanted to look at a couple of questions. First, what does the city have in terms of vacant land parcels? This gives us a sense of what can be developed under the current rules. An NDS staffer did an analysis a few years back which you can see here, which showed quite a lot of capacity to add residential units under the current zoning and even more considering SUPs and redevelopment. We wanted to update the plot count and map for today. We found that it has changed very little and that likely there is still capacity to add more density under current rules. We’d further note that since that 2011 analysis, the city has added somewhere between 2100 and 2900 residential units, depending on the source you use (Decennial Census, Census Building Permits Survey, and the city’s permits database). The 2011 analysis showed just over 600 vacant acres, and our analysis shows about 550, though some of this, it is worth noting, is UVA land (State Use Code of “Exempt Educational”). We excluded this from the map and plot count, but not the acreage count. This category is not broken out from the 2011 analysis. We think UVA has some intention of building affordable housing on at least some of these plots, so they ought not be discounted entirely. Below, you can see in green the areas of vacant land, most of which is residentially zoned or already in a PUD.

When presented with this data, some people have attempted to dismiss it by suggesting that most or all of the vacant land is in the flood plain. We decided to superimpose FEMA’s flood hazard map on the vacant land map to see to what extent this argument holds (no pun intended) water. You can see the results below, but the short answer is that only a small fraction of the vacant parcels lie in a FEMA hazard zone.

Second, we took a look at a particular combination of zoning and use that would allow for the addition of housing units — plots zoned R-2 that contain only one single-family housing unit. This is an interesting situation for two reasons. First, each of these plots is already zoned for greater density. The city might consider ways to incent current owners to add an additional unit, without any required change in zoning. Second, it demonstrates revealed preference. If demand for duplex units were very high, it would be reasonable to expect that the capitalized rental value of a second unit would exceed its cost of creation net of the loss of value to the first unit due to the negative amenity effect. The continued presence of more intensively zoned lots being used for single-family residences suggests that either the economics of duplexes are poorer than planners think or there exist some other barriers to duplex creation besides zoning restriction. The Planning Commission and consultant need to explain this anomaly and what, if anything, the new zoning ordinance will change in regard to it.

There are approximately 650 plots zoned as R-2 that contain a single-family-detached unit. This is greater than the 320 units that contain duplexes and also greater than the 525 parcels that contain single-family-attached units. Below, you can see R-2 zoned plots containing only single-family units marked in yellow. We present this information with the caveat that the city database is not always clear or consistent in its definitions.

A related situation that also involves potential underutilization is that of plots which are currently used for one single-family residence and which could be further subdivided under the current zoning rules. We first looked for SFH plots of greater than 0.4 acres, which would represent a bit larger than what is required for two lots of the current minimum R-1 lot size of 8,125 square feet. This represents an extremely rough cut, as it ignores minimum lot frontage rules, but also in the other direction excludes lots that may be subdividable that contain something other than one SFH. You can see the lots, of which there are approximately 1100, marked out below in blue.

We further filtered this initial selection of lots to try to eliminate lots that clearly would not meet the current minimum frontage requirements. It is worth noting that a minor zoning change that could free up more developable space would involve loosening these minimum frontage rules. Unfortunately, the city’s shapefile repository does not mark out street frontage. We would encourage the city to include this data in future iterations of the repository. We tried to estimate this by looking at the ratio between lot area and perimeter, assuming that lots are mostly roughly quadrilateral and that a large perimeter-to-area ratio indicates two short sides. We assumed one of these sides would be the street frontage. We required our “frontage estimator” to be at least 35 meters, which is about 20% larger than what would be required for two lots with the minimum required R-1 frontage (assuming structure placement is not in dead center of the street frontage). Applying these conditions left us with just over 500 eligible lots. The lots are below in purple. As with the underutilized R-2 lots, we think it is important to ask why owners have not taken advantage of this additional development capacity. If housing prices were truly far above marginal cost of production, it would make financial sense for homeowners to subdivide. On the other hand, if prices are below marginal cost of production, or buyer preferences are so far titled toward large lots that the diminution of value of the original house would outweigh the gains from creating the second lot, then it would explain why subdivision is not happening more frequently. It would also have implications for how homeowners might respond, or fail to respond, to zoning changes affecting their lots. And, of course, there could be other non-zoning barriers to subdivision that we are missing. The way to figure this out would be to analyze it — for example, talking to homeowners with these lots to determine if they know that they have the option of subdividing, if there are reasons they would be disinclined to subdivide; or analyzing the economics of subdivision. We are concerned that the Planning Commission and consultants have failed to carry out this elementary work.

Next, we wanted to consider commercially zoned plots that would appear to falling short of their highest and best use. We know that the country is experiencing a massive realignment of the retail sector, with the commercial center category particularly hard-hit. Fashion Square (in the county) for instance, has gone bankrupt and the foreclosure auction failed (the mortgage-holding bank ended up with the property). Seminole Square may not be far behind (and, in fact, in 2019, Seminole Square owner Great Eastern proposed 500 units of housing in a presentation to the Planning Commission; what became of that plan, we don’t know). There may be good opportunities to solve two problems at one stroke by facilitating commercial redevelopment into housing, particularly affordable housing, at scale. Commercial properties have infrastructure and are generally along transportation corridors. Retail developments in particular can be in desirable locations. We screened for commercially zoned properties with an assessed value per lot-foot of less than $40. We acknowledge the limitations of assessed values, but we think this is an interesting “first pass” that interested parties can use to identify parcels worth investigating further. Commercial properties are most likely capable of supporting a fairly high Floor Area Ratio (FAR); therefore we figured that $40/lot foot might reasonably be assumed to equate to under $100/buildable foot of residential. That seems like a reasonable land cost for a project that will have an affordable component, particularly if there is a lot of infrastructure already in place. If anything, these seems like conservative criteria. If we consider building mixed-use on such plots, with ground-floor retail (on sites that already proved themselves as retail locations) it is likely that economics will pencil out at higher per-lot-square foot prices, even with a high affordable unit share. Below, the map has these parcels marked in red.

Finally, one worry many correspondents express, and which we share, is that the FLUM could be a “tear-down plan”. This is particularly true of Medium Density Corridors, where 12-unit buildings would be allowed. These would almost certainly require demolition of any existing houses on the lots. Triplexes and duplexes are more likely to involve reuse or subdivision of existing houses, but at low enough lot prices, these could generate teardowns as well. We decided to take a very rough cut at identifying properties where “tear-down economics” might come into play. We looked for properties that met the following criteria: 1) non-vacant residentially-zoned properties 2) assessment quality category “C” or below 3) built before 2000 4) in State Use Codes (1-4) (i.e. excluding UVA properties, church properties, etc) 5) not a multifamily (i.e. R-2 zoning as a maximum) and 6) Assessed value per lot-square-foot of $20 or below. Again, our thinking here is that FAR would be lower than commercial plots, but we’d probably be looking at a land cost per buildable foot of $60-80, low enough for economically feasible redevelopment. What jumps out at us here is that this covers a pretty large amount of the city. Again, this is a very rough cut, but it would counsel that the city should proceed with caution if the intent is not to have a large amount of tear-down activity. It is also apparent that a lot of these parcels (but clearly not all, or even a majority) are in areas the city might designate as “sensitive”, which underscores the tension between trying to protect certain neighborhoods but also to catalyze economically viable marginal unit production. Below, in mustard, are the plots that met our criteria.

Finally, we include a link to our spreadsheet that provides this data in a granular form. We encourage people to have a look and tell us about entries they think shouldn’t be included, data errors, or omissions. Local neighborhood knowledge is obviously more valuable than programmatic database-crunching. But we hope this helps provides a starting point.

You can see the spreadsheet here. Please email comments to us here