The son of modernist Richard Neutra is looking for someone to buy and protect his father's last commercial building. It has been listed for sale for $3.5 million since November.

So far, Dion Neutra has had several offers, "but none that quite hit the nail on the head," he said in an e-mail. He insists that the National Register-listed building be sold with a protective conservation easement.

Built in 1950 as Neutra's office, the 4,800-square-foot building in Silver Lake, Calif., includes two apartments in the rear. Neutra wants to sell the building to establish an endowment to allow his Los Angeles-based Neutra Institute for Survial Through Design to continue.