GARWOOD — Last week, following a mandated public hearing, the Garwood Planning Board voted to approve amendments to the housing element of the borough’s Master Plan in accordance with state law and the most recent round of affordablehousing obligations. Robert Renaud, the borough’s affordable- housing counsel, said Wednesday that the borough will need to add 80 new affordable units to its current housing stock over the course of the next 10 years in order to remain in compliance.