Open House, a public art installation by Liz Glynn, transforms the Commonwealth Avenue Mall into an open air ruin of a ballroom. Lavish sofas and chairs evoke extravagant late nineteenth century interiors with a twist: the objects are cast in concrete, a utilitarian material used in modern architecture. Afterwards, lunch at Eastern Standard, purveyor of modern brasserie fare. BHV member Glenda Tall is your host. Meet at 12:50 p.m. (due to rain) at Open House on the Commonwealth Avenue Mall, Kenmore Square; use park entrance across from 490 Commonwealth Avenue. Lunch at 1:00 p.m., 528 Commonwealth Avenue. Pay individually. BHV members and guests.