Parcel Mapping and Subdivisions

Subdivisions and Condominiums are the most common simultaneous conveyances for most local tax mapping agencies. In many systems these important features are lost in the tax parcels. Why should we care about simultaneous conveyances and go to the effort of tracking and mapping them in tax parcel systems?

What are Simultaneous Conveyances?

Simultaneous conveyances are created when one or more parcels of land are created at the same time, i.e. simultaneously.

When several parcels of land are created at the same moment in time, such as lots in a subdivision, several parcels in a will, or sections in a township, all parcels have equal legal standing; they were all created at the moment of the filing of the subdivision of the plat, at the moment of the death of the testator, or in the case of a U.S. PLSS Township at the time the plat was approved. (Brown's boundary control and legal principles By Walter George Robillard, Curtis Maitland Brown, Donald A. Wilson, section 11.3 p 301

This is important to legal boundary analysis because this means that the boundaries within the simultaneous conveyance all have equal standing and in most cases this means there will not be junior or senior rights within the bounds of the simultaneous conveyance. The implication for tax parcels is that the interior boundaries should not be differentially adjusted or moved but should be treated with equal weight.

The contrary to a simultaneous conveyance is a sequence conveyance. These are parcels of land that are created. “Sequential conveyances are those written in deeds in which junior and senior rights between adjoining parcels” (Brown's boundary control and legal principles By Walter George Robillard, Curtis Maitland Brown, Donald A. Wilson, section 11.2 p 301). For tax parcel editing the term remainder parcel, the portion of a parcel that remain after a new parcel is created, is often used to describe the sequence conveyance situation. The implication for tax parcels is that in a sequence conveyance the parent parcel is senior, it existed first and must get it’s land first, the second parcel is subservient to the parent parcel. If there is an overlap situation, the parent parcel land is protected first.

There are many other evidence and legal description nuances that need to be considered in resolving discrepancies that should be interpreted by a land surveyor but it is important to recognize the basic differences in these descriptions in the tax parcel mapping environment.

Another characteristic of Simultaneous Conveyances is that they do not overlap. With each new simultaneous conveyance a new system for describing land is created. If there are appparent stacked subdivisions the latest subdivision area supersedes the prior subdivision, essentially vacating the prior subdivision. There are also nuances to this rule, such as with public right of ways and whether or not an official vacation of plat needs to be filed, and state law may create some variability but this is a general operating principle. The implication for the tax parcel mapping is that the most current subdivision should be the one used to control the geometry of the tax parcels. As new subdivisions are recorded and stacked on top of prior subdivisions, the area previous described should be changed to reflect the new survey.

Tax Parcel Mapping Versus Title Search

In most tax parcel mapping systems, it is sufficient to map the currently active simultaneous conveyances. The tax map may need to be able to identify or base legal descriptions on the underlying subdivision lots or condominium units but it may not be necessary to show the title history or evolution of subdivisions that existed prior to the current plats.

However, if an application is a mapped representation of the title history then it will be necessary to address stacking simultaneous conveyances. In some jurisdictions the office that tracks legal document recording may use a tract index to index the documents. A tract index summarizes real property transactions and is typically available in the offices of Recorder of Deeds. Only a few states require their recording offices to maintain this type of index. Among these states are Nebraska, North Dakota, Oklahoma, South Dakota, Utah and Wyoming. In addition, some other states permit recording offices to maintain tract indexes (for example, Kansas, Minnesota, Ohio, and Wisconsin). A mapped history of the simultaneous conveyances can provide the basis of these tract indexes.

In addition to document indexing, land surveyors need simultaneous conveyance history to complete boundary evidence and title boundary research. Having these records automated can increase the efficiency of historical document search for land surveyors and abstractors.

Understanding the intended uses and requirements of applications that will use the record of historical simultaneous conveyances will be important in the application and data design used to automate these records.

Tax Parcel Numbers – Limitations and Advantages

There has been some recent discussion about adding parcel numbers to the Home Mortgage Disclosure Act data sets (HMDA). This discusses some limitations and advantages of using tax parcel numbers outside the real estate tax system.

Typically tax parcel numbers are real estate tax system record identifiers that may also be used to relate tax parcel polygons and recorded documents to assessment and taxation records. They have evolved out of record based systems designed to track current and historical tax valuations, relate valuation to tax bills and manage tax credits and payments. As automated tax parcel mapping evolved the tax parcel number was a natural to include with the maps, providing a linkage to tax records.

Tax Parcel Number Limitations

One of the primary limitations of the tax parcel number is it often excludes tax exempt lands such as government managed land, churches, right of ways and public building sites. In some cases all of the exempt land is assigned the same code and in other cases no parcel number is assigned to exempt properties. There are exceptions of course and some jurisdictions do assign a tax parcel number to all parcels. Other idiosyncrasies with parcel numbers are

1) They may not be unique over time

2) They may change with annexations and tax district changes, and

3) Local formats and structure are highly variable.

Parcel Numbers Not Unique - Many local government have a practice of re-using parcel numbers when a parcel is split. If a portion of an existing parcel is conveyed the parent or remainder parcel often keeps the original tax parcel number that was originally assigned to the entire parcel. The geometry and legal description of the original parcel has changed with the conveyance or split but keeping the original parcel number allows many systems to create a linkage to the original parcel and be able to track the lineage. This practice is most common when the owner of the parent parcel did not change in the conveyance. Some property tax systems keep a parent-child table for tax numbers that explicitly stores the lineage of tax parcels, at least the lineage of tax parcel numbers, which can be used to trace the tax parcel history. If these tables exist and are used, then it is less of a problem to change the tax parcel number of the remainder parcel in a parcel split situation.

This practice of re-using parcel numbers is changing slowly with advances in automation of tax and assessment records and the migration to newer systems, especially systems linked to GIS. The practice of re-assigning tax parcel numbers is still fairly common throughout the U.S.

Affects of Annexation and Tax District Changes – Annexation changes a parcel’s tax district which can also change the primary real estate tax authority, for example if an unincorporated area is managed by the county, annexation to a city can transfer the primary real estate tax authority to the city. In some cases parcel numbers are changed with annexation. In most cases the history of the tax parcel number is tracked through parent-child tables.

Local Formatting – The variability of the structure and format of the local tax parcel number is legion. Spacing, punctuation, alphanumeric characters, length, rules and ordering are all subject to variation. Even in states with specified content individual county formats may have different spacing and punctuation in the tax parcel number. There are even counties where the tax number is formatted differently in the mapping software than in the tax assessor databases and this is surprisingly more common than expected. For the most part the software that manages the tax data dictates the format of the tax parcel number. There are many creative ways these software packages and local assessors embed location and parcel characteristics into the tax parcel number.

Tax Parcel Number Advantages

Even with all these caveats and variations locally assigned and managed tax parcel numbers are an important and essential data elements for many applications and downstream users of the data.

Identifies vacant land – Unlike site addresses tax parcel numbers provide a link to all taxable lands. Many jurisdictions do not assign site addresses to vacant land but is the land is taxable it will have a tax parcel number.

Connect to recorded and official documents – Many local governments, sometimes mandated by state law, recorded document numbers are included with the tax parcel number in the tax roll. These can include deeds, mortgages, mortgage releases, liens and many other documents such as permit records, inspections well and septic records. This can be very helpful when searching landownership even if the content of the linked documents may not be included in databases.

Identifies the entire parcel – The tax parcel number identifies and can be used to locate the entire parcel of land. Site addresses typically relate to just the structures on the land while the tax parcel identifier has information about the entire parcel including all structures in the tax parcel records connected by the tax parcel identifier.

Current and past records – The tax parcel identifier links to current and historical tax records, typically at least three years of past records. This makes it possible to see trends in tax bill payment history, trends in value and trends in use and tax rates.

As with any single data element, the tax parcel number is not a panacea, but it has enough value and application to be a useful addition to link to local tax and property records.