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New Hampshire Property Appraiser Using TatukGIS Editor

July 20, 2016

My name is Chris Mumford, and since August 2011 I have used TatukGIS Editor in support of my real estate appraisal work, nearly all of which involves complex valuations of land and high-value properties in the Lakes Region of central New Hampshire. My primary use of the Editor involves cataloging properties that comprise either an appraisal assignment or a comparable sale. Accurate geo-referenced GIS data is not readily available, so in almost every case I use the Editor to create custom vector data on the basis of deed descriptions, surveys, parcel cards, and high-resolution aerial imagery. All such proprietary data as well as numerous attributes is created in one of several custom SQL layers (easily built with the Editor), each of which corresponds directly with one or more MS Access applications and indirectly with the other Office productivity software (Word, Excel, Publisher) that I use in production of my actual appraisal reports.

The State of New Hampshire, as is true for most states in the U.S., offers numerous vector data sets such as streams & waterbodies, conservation lands, roads, etc., all of which can be downloaded and used free of charge. Such large-scale data is seldom completely accurate when viewed against ortho aerial imagery at the relatively small scales in which I commonly work, and the Editor again comes into use for minor edits of roads, shorelines, etc. When utilizing such data, my ultimate goal is to analyze parcels and improvements on the basis of areas, slopes, buffer zones, setbacks, etc., all for the purpose of enhancing both my Highest and Best Use analyses as well as the quantitative aspects of the valuation methodology, which in most cases involves the Sales Comparison approach.

New Hampshire also makes available large scale DEM (Digital Elevation Model) data, which I download and use for two purposes: The first is creation of contour lines at intervals of my choice by means of a processing feature in the Editor. The second use is visualization of terrain (slopes, aspects, watersheds, etc.) by means of the 3D feature in the Editor. I’m eagerly awaiting the release of high-resolution LIDAR data, which will allow for: highly accurate slope, aspect, and contour analysis; improved visualization of our region’s numerous stone walls, many of which mark property boundaries but are difficult to discern in aerial imagery; and greatly improved 3D visualization of terrain.

Yet another feature of TatukGIS Editor that I often use is the Rectification tool, which allows me to overlay and geo-reference imagery such as property surveys, parcel maps, floor plans, etc. I manually translate geo-referenced imagery into vector data, or simply use it to edit or ground truth existing data. For even greater accuracy, I frequently use third party software to convert metes and bounds descriptions of a given property into vector data, which I then geo-reference and import into the Editor. Further editing, easily accomplished with the Editor, is nearly always required to compensate for compass declination and to make slight shifts in placement. The result of this process is an accurate parcel shape that is geo-referenced with a high degree of accuracy. On more than a few occasions I have advised clients of significant discrepancies in property descriptions, and it is always the case that the subjectivity offered by GIS analysis and mapping imparts an added level of confidence to my final opinion of value.

In conclusion, I can attest that the Editor is intuitive and relatively easy to learn. In daily use, its many features are sufficiently robust for my purposes without being overly complex or difficult to use. The software is updated almost weekly, and on-line support is readily available and quite responsive to user needs. Perhaps most importantly, Editor is reasonably priced for a small shop such as mine.

Chris Mumford
Plymouth, N.H., USA

(Related item: 2023 blog)