BostonSF reports residents of a Boston neighborhood are witnessing the first ever three-story modular home being put together in their area.  Westchester Modular Homes of Greater Boston (WMHGB) supervised the assembly of the six-module unit.  The 3,360-square-foot home sits on a lot only 20 square feet larger, and will feature many high-energy-efficiency and green-performance elements such as solar panels for heating water and rainwater cachement for landscaping.  The owners expect to receive the Leadership in Energy and Environmental Design (LEED) H Platinum certification for their home.  The owners further intend to set up a website to educate people about the house, and about improving neighborhoods by living green.  Scott Jones, President and CEO of WMHGB, said, “With a limited lot size in an urban setting, these homeowners have maximized their living space.”