The $11 million Bowers Brook affordable housing complex for seniors held opening ceremonies last week. It is the second project of its kind in town, said Louis Russo, whose Harvard firm, L.D. Russo Inc., was the developer. Thirty-eight of the 42 apartments at 196 Ayer Road are occupied, Russo said. A one-bedroom apartment rents for $695 a month, a two-bedroom, $1,195, he added, noting that funding was provided by several state and federal agencies along with private investors.