Tour a rustic-modern attic addition complete with an open-concept living room, principal bedroom, bathroom and bar area for entertaining. Plus, steal budget decorating tips from homeowners Karen Troubetzkoy and Derek Schreyer — writers and producers behind shows like The Listener and 18 to Life — who used sheets as curtains, an unused window frame as a bed footboard, curbside furniture finds and a cheap and simple tub faucet.