The Research Triangle Region of North Carolina is a rapidly growing area of more than 1.5 million residents centered around Raleigh, Durham, Chapel Hill, and the Research Triangle Park. With a population increase of more than 25 percent in the past 10 years, real estate is a large and important industry with annual sales of more than $1.5 billion. The primary repository for all real estate-related data in the region is the Triangle Multiple Listing Service (TMLS). TMLS, a subsidiary of the Raleigh Regional Association of Realtors, is charged with maintaining property listing databases and providing related training for realtors and other real estate professionals located in the Triangle area.

Until recently, TMLS used a Windows-based dial-in system, with no graphics or mapping capabilities, for its members to access property information collected from local municipalities. With nearly 5,000 Realtors using the system, overhead associated with hardware, phone lines, and distribution of software CDs was staggering. In order to reduce system overhead and increase functionality and availability, TMLS embarked on a major system upgrade. The basic requirements for this new system were that it be Internet-based, not require the distribution of CDs, have a major GIS component, and be simple to use.

To meet the needs of this new system, TMLS issued a request for proposal (RFP) for the design and development of a new Tax Parcel Information System (TPIS). TerraVerge Corporation, an Esri Business Partner, responded to the RFP and presented the TMLS with a live demonstration of several ArcIMS systems.

"When compared to other systems we reviewed, we saw that ArcIMS technology can provide our members with an Internet-based system that requires minimum training and a more comprehensive database of property tax and GIS information," says Ray Larcher, president of TMLS.

TerraVerge's system is powered by a combination of ArcIMS, Macromedia ColdFusion, and Microsoft SQL Server. ArcIMS and the ArcIMS ColdFusion Connector provide all mapping and GIS functionality; ColdFusion handles tabular data queries, session management, and security; and SQL Server houses all tabular attribute data.

Challenges

As part of this project, TerraVerge was tasked with collecting and maintaining GIS and tabular data from seven Triangle area counties. As luck would have it, all the municipalities in question were users of Esri software, so the integration of GIS data into the TPIS was a snap. However, the tabular attribute data was another story. As might be expected, each county used a different database or proprietary data management system to house their tabular property data, with varying data fields and levels of property information detail. This proved to be the most challenging portion of the project.

To address these issues, a user group made up of local real estate agents, appraisers, TMLS staff, and other real estate professionals was formed. Through meetings with this group and discussions with GIS and tax professionals from the various counties, templates were created for search functions and reports to be included in the system. The fields required for these searches and reports were then mapped to the tabular data tables supplied by the counties, and a SQL Server database was designed around these requirements.

With the GIS portion of the system being handled by ArcIMS and the tabular database and templates complete, all that was left to do was link the GIS data to the tabular databases. "By using Property PIN numbers available in both the shapefiles and SQL Server data, we were able to easily tie map features to the detailed tabular data," says Keith Rokoske, a system developer with TerraVerge. "The ability to use the ArcIMS ColdFusion Connector allowed us to seamlessly integrate the spatial and tabular data."

TPIS in Action

With the completed TPIS system, TMLS members now have access to current GIS and property information from any computer with an Internet connection and browser. Using TPIS, real estate professionals can now locate properties using a variety of tabular and spatial search tools, create and save custom searches, print mailing labels, and download TPIS data for use with other desktop software. Additionally, a large amount of GIS data, including roads, topography, orthophotos, zoning, schools, and other layers, is available on the system.

"The new TPIS system has fundamentally changed the way local agents can perform property searches," says John Tyrell, a local real estate agent. "With the added mapping and map-related property selection tools, we can now include geographic elements in our selection criteria. This was something we could never do with the previous system."

In addition to increased spatial and tabular functionality, the new TPIS system greatly reduced hardware, software, and maintenance overhead. "Our users now have a more robust system with increased accessibility and functionality," says Larcher. "Additionally, since the system is purely Internet based, we no longer need to distribute CDs or maintain banks of modems and phone lines."

For more information, contact Randy Page, president, TerraVerge Corporation (tel.: 919-629-0090, ext. 101; e-mail: randy.page@terraverge.com; Web: www.terraverge.com).