Construction has begun on a project that will add 18 condos and four penthouses to the top of a historic four-story office building at 429 N. Pennsylvania St. The project, dubbed The Residences at 429, is adding five additional floors to the 1920 building, which was built for Reserve Loan Life Insurance Co. and is listed on the National Register of Historic Places. Units will range from 1,100 to 4,000 square feet, and prices are $300,000 to $1.4 million. The developer is locally based Stenz Corp. Projects that add floors to existing buildings are rare in Indianapolis but common in larger cities. What do you think? Will these condos sell?