2013 GISCO Track, Using GIS to Help Appraisal Staff Value Property by Pete Coventry and Adam Hoppe

Getting it Done

Using GIS to Help Appraisal Staff Rapidly Update and Improve Property Data

Pete Coventry, Adam Hoppe Boulder County Assessor’s Office

GIS Department Boulder, Colorado

Overview • Boulder County • Assessor’s Office structure Data Mining • From the Assessor’s Database • Getting it into GIS

Focus on Residential Properties

GIS for Appraisal work • In the field • Capturing Attributes (valuation)

• Analysis & Modeling

Where we work

Geology.com

720 square miles One-third plains Two-thirds mountains 125,000 real properties 98,000 residential

Where we work

Diverse Landscape

Diverse Properties

Why is property Assessed • Basis for generating tax revenues for local services

Assessors Role • Identify and values property within the county in

accordance with state law • Equalize property values/ taxes distributed fairly

Re-valued every odd # year

How we work

Teams = Geographic Areas

Assessor’s GIS Department

Led by Cindy Braddock • 3 GIS Specialists • 3.5 GIS Techs Responsible for… A LOT!

Data Mining

Why and How • Requests for information

– Public, partners, other County departments

• Helps us improve quality of information • Understand what we’ve already got

– Right, Wrong, Inconsistent – Know what to fix

100’s of tables 1000’s of fields

Add tables Join on Key Field Set requirements/parameters

“Bubble” Maps

Permit Fieldwork • Status as of January 1st • Remodels, other high $ improvement adds

value • Generates tax revenue for our districts • New residential construction

– Vacant to residential changes assessment rate – Determined by existence of a foundation

Mountain Attributes Human Judgment: • View • Privacy • Access

Mountain Attributes GIS Terrain Analysis captured: • Topography • Aspect

Dick’s Views on Views

Field Data -> Excel Spreadsheets-> Mass Uploaded into Database

Examining Sales Ratios

Estimated Sales Price (ESP)/Time-Adjusted Sales Price • Any ratio between 0.95 and 1.05 is ‘acceptable’ • Sales ratios << 1.00 – UNDERVALUED ESP? • Sales ratios >> 1.00 – OVERVALUED ESP? • Cause: incorrect or missing property information?

Sales Ratio =

Planes, Trains & Automobiles…

Planes, Trains & Automobiles…

Actually… Power Lines, Towers, and Railroads

Planes, Trains & Automobiles…

…Automobiles (Traffic, really)

GIS Analysis

The Heartbreak of…

http://geology.com/articles/expansive-soil.shtml

2008

2008 - 2009

2008 - 2010

2008 - 2011

2008 - 2012

Thanks for attending! Any questions??

Adam Hoppe & Pete Coventry Boulder County Assessor’s Office

GIS Department Boulder, Colorado

Adam Hoppe – [email protected] Pete Coventry – [email protected]

Geographic Areas = 5 Models

Sales Ratio = 1.6

• Sold for $514,000 • TMADJ SP = $513,000 • ESP = $800,000 • Overvalued ESP • Time for review

Sales Ratio = 0.81

• Sold for $675,000 • TMADJ SP = $660,000 • ESP = $540,000 • Underestimated ESP • Appraiser will review property attributes to determine if incorrect or missing

Coming Soon…

Bye, bye ArcReader Hello ArcGISExplorer • More bells and whistles and flexibility for the

users (appraisers) • Much Faster • More customization on the front end which

helps deliver more useful maps • More programming… C#