THIS OLD HOUSE kicks off the second project of the 35th Anniversary Season: an addition to a 1966 Colonial in historic Lexington, Massachusetts. Homeowners Jeremy and Jody Kieval would like a makeover that includes more sunlight and a new farmer's porch. Inside, the overflowing playroom needs to be relocated. Jeremy wants his dream kitchen to become the new heart of the home, so the old kitchen will be gutted and redesigned. A new addition will include a mudroom and access to the garage. The upstairs plan includes two more bedrooms, a laundry room and a sitting area over the garage. Roger shows Kevin how the small stream in the backyard will be protected during construction.