The function MakeHouse describes the process of building a house.

void MakeHouse(IloModel model,
               const IloNum* dur,
               const IloNum startMin,
               const IloNum endMax,
               const IloUnaryResourceArray workers,
               const IloNumVar makespan) 

The following lines of code define the five houses to be built. The earliest start and latest end dates for the first, second, and fifth houses are the origin and horizon of the schedule, but the third and fourth houses have an earliest start date of 7 and a latest end date of 79.

  /* CREATE THE ACTIVITIES AND CONSTRAINTS FOR THE HOUSES. */
  MakeHouse(model, durationsDesign1, 0, horizon, workers, makespan);
  MakeHouse(model, durationsDesign1, 0, horizon, workers, makespan);
  MakeHouse(model, durationsDesign2, 7, 79, workers, makespan);
  MakeHouse(model, durationsDesign2, 7, 79, workers, makespan);
  MakeHouse(model, durationsDesign3, 0, horizon, workers, makespan);