Renovation and expansion work should start later this month at the North Montco Technical Career Center. The plans call for electrical, plumbing, heating and air conditioning upgrades and an 8,000-square-foot addition fronting on Sumneytown Pike to house a restaurant and beauty shop.  The public would have access to the addition, but not the rest of the building.  The project will take 18 months at a cost not to exceed $12 million, and the restaurant will probably open in the spring of 2012.