CoStar Group Inc

Washington, DC - September 19, 2012 - CoStar Group, Inc. (NASDAQ: CSGP),  commercial real estate's leading provider of information, analytics and marketing services, today announced its Property & Portfolio Research (PPR) division has launched an expanded multi-family product powered by CoStar's industry-leading commercial property database.

CoStar tracks detailed information on almost 400,000 multi-family properties in 210 U.S. markets and has been building the most comprehensive database of multi-family properties in the industry. The Company has established a dedicated team of 40 individuals that is specializing in the research and verification of multi-family information.   Along with independent research, analytics and actionable insights provided by PPR's team of over 40 economists, the PPR multi-family product is designed to meet the information and analytics needs of PPR's clients, including commercial banks, financial institutions, pension funds, insurance companies and government and rating agencies.

"We believe the unparalleled combination of strong analytics from PPR coupled with CoStar's unmatched, comprehensive data gives our clients who are interested in multi-family an outstanding resource for analyzing properties," said Andrew C. Florance, Founder and Chief Executive Officer of CoStar.

CoStar has already expanded its detailed coverage on more than 25,000 multi-family properties, with information on unit count, unit size, asking rent, effective rent and vacancy. The number of properties with expanded information is expected to grow rapidly over the next 12 months and beyond.

"With coverage of 210 markets, PPR plans to provide insight into the vast majority of U.S. cities, not just the big markets," said Hans Nordby, Managing Director of PPR.  "This is a key point for lenders, who often serve a wide geographic footprint, as well as investors, who are investing in smaller cities."

"From an analytics perspective, we are going where no apartment research group has gone before," Nordby continued.  "We expect to offer effective rent estimates, including forecasts at the metro and sub-market level, as well as demographic and demand driver screens at the street corner level, leveraging CoStar data that simply is not available elsewhere."

About PPR

Property and Portfolio Research (PPR) provides unparalleled expertise and objective thinking in analyzing and forecasting commercial real estate markets. PPR sets the pace in offering independent research, a unique set of analytic tools, and actionable insights to investors on hundreds of global markets in North America and Europe. Clients range from commercial banks and financial institutions to pension funds and insurance companies as well as government and rating agencies.

With a dedicated commitment to providing the best in commercial real estate research, PPR's widely respected knowledge of the markets helps clients to stay ahead of market trends, act decisively, and feel confident about their investment decisions. PPR is a division of CoStar Group.

About CoStar Group, Inc.

CoStar Group (NASDAQ: CSGP) is commercial real estate's leading provider of information, analytics and marketing services. Founded in 1987, CoStar conducts expansive, ongoing research to produce and maintain the largest and most comprehensive database of commercial real estate information. Our suite of online services enables clients to analyze, interpret and gain unmatched insight on commercial property values, market conditions and current availabilities. Through LoopNet, the Company operates the most heavily trafficked commercial real estate marketplace online with more than 6.1 million registered members and 3.6 million unique monthly visitors. Headquartered in Washington, DC, CoStar maintains offices throughout the U.S. and in Europe including the industry's largest professional research organization.www.costar.com.