A $1 million gift to the Greek Orthodox Archdiocese of North and South America -- the largest one-time donation in the history of the archdiocese -- will go toward building a Washington office, a D.C. representative of the church said this week. The donation, from multimillionaire Bill Colevas of Upper Marlboro, was announced last Saturday in New York at a meeting of the Archdiocesan Council of the Greek Orthodox Archdiocese of North and South America, said Dean G. Popps, the church's Washington representative. Popps said Colevas is a longtime member of St. Sophia Greek Orthodox Cathedral in Northwest Washington. Colevas' donation will go toward the building of an "office/residence complex" in Washington for the church, but its headquarters will remain in New York City, Popps said. "As agendas grow for the church to address -- abortion, pornography, homelessness -- it's become mandatory that every major faith have an office in Washington," Popps said. "{Colevas} just said, 'I believe in that vision for the Greek Orthodox Church. I want to see that happen in my lifetime.' " Popps said that the church would like to have its headquarters in Northwest Washington along Embassy Row, where other churches have offices. He said the church expects to pay $2 million to $3 million for property to build on, "so Mr. Colevas' gift will serve as a downpayment for that." Colevas, a native of Washington, has been a paving contractor, real estate developer and businessman in the metropolitan area for 39 years, and is president emeritus of Arundel Asphalt Products Inc. in Forestville. He could not be reached for comment. "He's a very unassuming, humble man, with a terrific amount of underlying spiritual strength," said John Tazlarides , dean of St. Sophia Greek Orthodox Cathedral. He said Colevas has made "similar gifts" to the parish. "He's low-keyed, yet always responsive to the needs of the church and the less fortunate," Tazlarides said. Popps, a McLean lawyer, said there are about 25,000 members of the Greek Orthodox Church in the greater Washington area, and about 2 million members nationwide.