What Is Assemblage
Assemblage is the combining of two or more adjacent parcels into a single larger tract that generates additional value beyond the sum of individual parcel values. This added value, called plottage increment, arises because the combined property has utility or marketability that the separate parcels lack.
In property tax assessment appeals, assemblage matters because assessors sometimes apply an assemblage value to your property even when the parcels remain legally separate. If your property is adjacent to others under the same ownership or control, your assessor may claim plottage value exists and inflate your assessment accordingly. Challenging this requires understanding how assemblage actually functions and whether the conditions for plottage value truly exist on your specific property.
How Assessors Use Assemblage in Valuations
Assessors typically apply assemblage value using the market approach, comparing your property to recent sales of similarly assembled parcels in your area. They calculate what a buyer paid for combined parcels and attempt to allocate that sales price across individual lots.
The problem arises when assessors assume assemblage value without market evidence. If comparable sales in your jurisdiction show no transactions of assembled properties, or if the assembled parcels have physical or legal constraints preventing actual combination (zoning restrictions, easements, separate utility access), the assemblage premium is speculative.
At the board of review hearing, you can challenge assemblage value by presenting evidence that:
- No comparable sales of assembled properties exist in your market area within the relevant time period
- Zoning regulations or deed restrictions prevent actual combination of the parcels
- The parcels serve different functional purposes (one commercial, one residential) and cannot be reasonably combined
- Separate physical access points or utility infrastructure exist, eliminating practical benefit from assemblage
- Your assessment ratio (assessed value divided by market value) exceeds the jurisdiction's legal ratio, suggesting inflated valuation
Plottage Value Is Not Guaranteed
Assessors often conflate assemblage with plottage value. Assemblage is the physical act of combining parcels. Plottage is the premium value that results from that combination. These only coincide when a buyer actually wants the combined property and will pay a premium for it.
If your adjacent parcels lack development potential, cannot legally combine due to zoning, or serve separate functions, no plottage value exists. Your assessor cannot simply assume it. In assessment appeals, request that your assessor provide the sales data supporting the plottage percentage applied. Most jurisdictions require assessors to quantify this using actual comparable sales within the past 12 to 24 months. If they cannot produce specific comparables, the assemblage adjustment is indefensible.
Common Questions
If my parcels are separately deeded but I own them both, will my assessor automatically assign assemblage value?
Not automatically, but increased risk exists. Assessors in some jurisdictions monitor deed records and flag common ownership. However, ownership alone does not justify assemblage value. The property must have characteristics that a willing buyer would pay a premium for when combined. Present evidence of independent utility for each parcel to counter this.
Can I remove assemblage value by transferring one parcel to a different owner?
Possibly, but tax law varies by state. Some jurisdictions require severing the parcels through formal subdivision and demonstrating that each operates independently for a reasonable period before reconsidering the assessment. Consult a local property tax attorney before pursuing this strategy, as improper severance can trigger capital gains consequences.
What evidence should I bring to my board of review hearing to challenge assemblage?
Bring a professional appraisal showing separate market value for each parcel without assemblage premium, recent MLS sales data for comparable single parcels in your area, zoning documents showing restrictions on combining the parcels, and a cost or income analysis showing each parcel generates independent revenue or utility. If comparable assembled properties sold for lower premiums than your assessor applied, highlight those specific transactions.
Related Concepts
- Plottage – the value premium created when parcels are combined, distinct from the act of assemblage itself
- Land Value – the underlying value of each parcel before any assemblage adjustment is applied