The NVM real estate association’s Open House Day drew a large crowd on Saturday. Roughly 66,000 prospective buyers visited the participating homes-more than at the previous edition in March, when NVM Open House Day attracted 52,000 visitors.Agents point in part to Saturday’s sunny weather. More homeowners also opened their properties for viewing this time. Between 11:00 a.m. and 3:00 p.m., house hunters could walk through nearly 14,500 homes without an appointment.