Commercial real estate listings and data giant CoStar waded into the residential real estate space Monday, announcing a $250 million deal to acquire Homesnap.

The all-cash deal will give CoStar access to Homesnap’s extensive roster of residential brokerage clients, CEO Andy Florance said in a statement, and letting it market combined commercial and residential products like advertising and lead generation to brokerages that operate in both spaces.

“The acquisition of Homesnap will enable us to enter a new space and expand the total addressable markets in which we can compete. The estimated value of commercial real estate assets in the U.S. is $16 trillion. With the new addition of clients and information covering 90 percent of the estimated $27 trillion dollar U.S. residential real estate market we are almost tripling the size of our addressable markets,” Florance said. “We will continue to differentiate our residential real estate portal and solutions by working solely to help agents market their listings and their brands, which is in sharp contrast to other portals that increasingly advertise on top of agent listings and offer brokerage services directly.”

Homesnap currently counts 300,000 real estate agents nationwide as its active users, and through deals with many multiple-listings services has put its Homesnap Pro service in the hands of 1.1 million users representing around 90 percent of the country’s residential agents, the company said. Those partnerships with MLSs have also helped it build a real estate portal to rival those built by Zillow and Redfin.

The acquisition of Homesnap will quadruple the number of professional, paying brokers and active agent users on CoStar Group’s U.S. platforms from approximately 100,000 today to over 400,000, the company said. Its marketing, lead generation and client collaboration tools will also help its current commercial broker customers, Florance said, and offer more complex packages to non-agent CoStar clients like investors, banks, government agencies, appraisers and suppliers, and brokerage firms.