Historic districts, significance, and current integrity v. future integrity

An article caught my eye the other day. The Durham, North Carolina, Herald-Sun posted an article about the expansion of the Cleveland-Holloway historic district, and the ensuing controversy regarding which properties to include in the expansion, and which properties to exclude. You can read the article here.
Particularly, one 2-acre lot has been at the center of the conversation: a vacant (but prime for development) parcel. So, why would a vacant parcel be included in a historic district? Without any historic resources, how does the parcel warrant inclusion? The answer may have something to do with the properties surrounding the lot, and what future development on the lot might look like. However, before we try to get to the bottom of the vacant lot and the historic district, let’s talk a little about the initial process for determining the inclusion of resources in a historic district.
Evaluating a property to understand its historic significance can sometimes get complicated. The National Park Service (NPS), through its National Register Bulletins, provides a framework we can use to guide us through the evaluation process. By determining integrity, which the NPS defines as “the ability of a property to convey its significance,” we can come to a good conclusion about whether a property would be eligible for inclusion in the National Register, or a contributing resource in a local design review district.
When we consider the integrity of a resource, we’re looking for signs of how the resource has changed or hasn’t changed through the decades. If I’m asked to judge the integrity of a resource, I ask myself this question first: if we could bring the original builder/occupant of the property forward in time to join us today, would he or she recognize the property as their own? Has the neighborhood changed radically since the building was constructed? Has the building itself changed radically over the years? The less sure I am that time traveler would recognize the building, the less sure I am that building retains the integrity needed to be considered a historic resource.
And when we judge integrity, the NPS asks to us to judge based on seven different aspects, including location, design, and setting, among others. Location often comes down to, as you might expect, physical placement, and usually comes into play when a property has been moved. Design may focus on the single property and its appearance, a streetscape, or the entire district, and oftentimes these aspects all help to determine significance and integrity. Not only is the alteration of the building important to consider; alterations in the vicinity of the building that alter design must also be considered. Finally, setting considers the character of the property in question. A good example of loss of setting: the historic 1830s farmstead constructed on a 200 acre farm that has been subsequently swallowed up by subdivisions of new homes on the land. Even though the original house still exists, the surrounding land has been so severely altered that it would be difficult to capture the feel of the property as a working farm. If you want to dive into the different aspects of integrity, you can read more here.
In the case of the Durham expansion, I think the central issue comes down to this: future construction on the vacant lot could compromise the integrity of the local district as a whole, based on the aspects of design and setting. Therefore, one way to stave off future construction that doesn’t fit into the character of the district is to add the vacant parcel to the district, thereby (if the ordinance is written to provide oversight for infill/new construction) putting future construction under design review. In the case of the Durham expansion, the current property owners don’t want the added layer of regulation, while many of the adjacent owners don’t want an out-of-scale development that could jeopardize the character of the district.
If this controversy came before you, how would you resolve this issue? Traditionally, historic districts were enacted to preserve significant properties. But, when we consider design and setting when evaluating the integrity of significant properties, adjoining parcels and what’s built on them can influence the look of the district, for better or worse.
You can provide your thoughts in the comments section below.