The merging of adjacent parcels into one common ownership without increasing the unit value is known as?

The merging of adjacent parcels into one common ownership without increasing the unit value is referred to as assemblage. In property appraisal, assemblage involves combining multiple parcels of land into a single entity for purposes such as developing a larger property or optimizing the use of land. However, this process does not inherently increase the value of the individual units being merged, which distinguishes it from related concepts.

Assemblage is often confused with other terms like development or consolidation. Development typically refers to the process of enhancing a property by adding improvements (like buildings or infrastructure), which usually increases value. On the other hand, consolidation is a term that can imply a similar merging of properties but may not come with the nuance of a lack of increase in unit value that assemblage specifically highlights.

Thus, assemblage accurately describes the situation where adjacent parcels are combined without resulting in an increase in their combined value.