How do you make a 25,000-square-foot office building with drop ceilings and dated conference rooms feel opulent, design-forward, and homey? That was the challenge for the 25 designers tapped for the fifth annual Kips Bay Decorator Show House Dallas, open now through November 13.The Dallas Show House, located near downtown in the Turtle Creek neighborhood, is an extension of the original Kips Bay Decorator Show House that debuted on Manhattan’s Upper East Side in 1973. It featured over-the-top spaces by acclaimed interior designers, with ticket proceeds going to raise money for after-school programs for New York City children. More than fifty years and $30 million later, the organization has only two other outposts: West Palm Beach and Dallas. In other words, it’s a big moment…