Demolition is scheduled to begin this week at the southeast corner of West Fifth and Colorado Streets in downtown Austin, clearing several buildings for the construction of a 47-floor residential and office tower developed by Texas private equity firm Stonelake Capital Partners. The project, at the moment known simply by its address at 415 Colorado, will contain approximately 328 apartment units located above 110,000 square feet of office space in a 640-foot tower designed by the Houston-based firm Ziegler Cooper Architects -- best known around here for the . . .