The Planning Board will hold a public hearing Monday night on two “smart growth” affordable-housing proposals. Selectmen have already approved these 40R projects, and Planning Director Stephen Costello said the Planning Board will decide soon whether to recommend them to Town Meeting. The projects include Plimpton Press, which would consist of approximately 300 units in the former press factory off Lenox Street, and Regal Press, which calls for 70 apartments in the Guild Street building owned by the Regal Press printing company. The state’s Chapter 40R law requires that at least 20 percent of the units meet the state’s criteria for being affordable. The housing typically takes advantage of nearby public transportation and could mean payments from the state to the town. The Planning Board meeting begins at 6:30 p.m., with the public hearing to begin at 7 p.m.