Definition
Plottage is the increment of value that arises when contiguous parcels of land are assembled into a single, larger tract. The combined unit commands a higher per-unit price than the individual parcels would fetch separately, because the assembled block opens development opportunities unavailable to fragmented lots. The term appears most frequently in real property appraisal and in eminent domain proceedings, where the question of just compensation may require accounting for — or deliberately excluding — the enhanced value attributable to assemblage.
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Common Language
Modern common usage (Wiktionary): "The increase in value of land achieved by parcelling smaller plots into a developable unit."
Historical common usage (Webster's 1913): Not defined. The term does not appear in Webster's 1913, reflecting its status as a term of appraisal art rather than ordinary English.
The Wiktionary definition is broadly accurate but collapses a distinction that matters in legal contexts. In appraisal and eminent domain law, plottage refers specifically to the value increment resulting from assembly — not the act of combining parcels itself. Whether and how that increment is compensable is a contested legal question, not merely a descriptive one.
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Why It Matters in Research
Plottage sits at the intersection of appraisal methodology and constitutional takings doctrine, and researchers moving between those two fields will encounter the term used differently in each.
In appraisal literature and early eminent domain cases, plottage value was treated as a recognized component of fair market value — something an appraiser should account for when valuing assembled land. Black's 2nd Edition captures this baseline use: contiguous lots held by a single owner have a combined value exceeding their sum, and that premium is plottage.
The harder research problem arises in condemnation proceedings where the government takes only part of an assembled parcel, or where parcels were assembled in anticipation of a public project. Courts have divided on whether plottage enhancement is properly included in just compensation, excluded as speculative, or excluded because the assembly itself was driven by the very project causing the taking. Researchers tracing this line of cases will find the term used inconsistently across jurisdictions and eras, sometimes describing the value increment, sometimes describing the appraisal technique for measuring it, and occasionally (in older materials) used interchangeably with "assemblage" — a related but technically distinct concept.
Historical sources in the Law Mind corpus will rarely define plottage explicitly. It appears most often in passing, in appraisal testimony summaries and in discussions of severance damages. Do not expect a clean doctrinal definition in pre-1950 case law; the term was borrowed from appraisal practice and its legal contours were worked out gradually.
For researchers working on condemnation, regulatory takings, or urban renewal history, plottage questions frequently arise alongside unity-of-use analysis and the before-and-after valuation method. Tracking how courts treated plottage evidence is a useful lens into how just compensation doctrine evolved in densely developed urban jurisdictions.
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Historical Dictionary Support
Black's Law Dictionary (2nd Ed.) provides the only historical dictionary treatment in the Law Mind corpus. Its definition is functional and appraisal-focused: plottage is the additional value given to city lots by their contiguity, enabling use as large blocks. The accompanying citation to In re Armory Board, 73 App. Div. 152, 76 N.Y. Supp. 766, anchors the term in New York eminent domain practice of the early twentieth century, which was among the most developed in the country given the density of urban condemnation activity in that jurisdiction.
Black's does not address the valuation disputes that the concept would later generate, nor does it distinguish plottage increment from assemblage as a process. Later editions of Black's and modern appraisal dictionaries (including The Dictionary of Real Estate Appraisal published by the Appraisal Institute) refine these distinctions considerably. Researchers relying solely on the 2nd Edition definition will have a sound starting point but will miss the doctrinal complexity that developed through the mid-twentieth century.
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Jurisdictional Note
New York decisions dominate the early case law on plottage, owing to the volume of municipal condemnation activity in New York City. Other jurisdictions adopted or rejected the concept unevenly. Some courts have declined to recognize plottage as a separate element of value, treating it as already embedded in fair market value analysis; others have addressed it explicitly in jury instructions or in rules governing expert testimony.
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