Bridgewater will allow housing in the downtown business district for the first time since 1957 as a result of zoning changes approved by the Town Council Sept. 3. The town will welcome downtown housing by special permit, provided the residential space is located on the upper floors of commercial buildings. Apartments that already exist in the area were grandfathered when the town adopted the 1957 zoning law. A Bridgewater master plan called for the change about 10 years ago, but it was not made until now. Officials hope the new zoning will encourage reinvestment in downtown buildings.