An apartment high-rise planned for downtown Milwaukee is getting bigger − marking the second time its developers have expanded their proposal. The Edison was initially planned as a 15-story building with around 200 units overlooking the Milwaukee River at 1005 N. Edison St. Revised plans filed with the city in February called for a 28-story high-rise with 296 apartments. Now, The Edison’s developer, Madison-based The Neutral Project LLC, is planning a 32-story tower with around 350 apartments, said Nate Helbach, the firm’s managing partner. …The Edison would use an unusual construction technique known as mass timber, or cross-laminated timber. That process uses layers of wood pressed together to create columns, beams and other building frame components. Apartments, offices and other buildings made from timber provide a lower carbon footprint than conventional construction. They also can create a more attractive atmosphere, featuring exposed wood interiors.