Unknown house with triangular roof
Single Family Residence
The post card is produced by Star Post Card Co. 65 Vernon St. Springfield. It purports to be a proof card, which would be given to the owner of the house, who could then buy more of them.
This is a rather distinct house, but it is not necessarily in Springfield. The white windows are atypical for Springfield for this era.
It is also possible that this house is on a corner lot, and that we are looking at the side of the house rather than the front, making it a little harder to identify.