Selectmen and Planning Board members will hold a joint meeting Monday to vote on a housing production plan. Planning Board chairman George D. Wadsworth said in an interview the plan includes an assessment of the housing demands in town, particularly affordable housing, and provides a blueprint on how to fulfill those needs. The 100-page plan was prepared for the town by LDS Consulting Group of Newton. If approved, it will be submitted to the state Department of Housing and Community Development. If the state certifies the plan, the town could use it as protection against unwanted 40B affordable-housing proposals, in which developers can sidestep some local restrictions if they plan to include affordable housing. The meeting is at 7 p.m. at Town Hall.