A stock house plan is a ready off the shelf set of construction drawings. Every plan is designed to meet one of the national building codes for residential construction. Many stock home plans began their lives as a custom designs for specific clients. Often, builders will commission a designer or architect to create a plan for them, but, in exchange for a reduction in the standard design fee, will allow the designer to resell the plan outside of their competitive area. The builder saves money on the front end and the designer holds on to the right to resell their plan.
Since a stock plan is not drawn for any specific location, the designer often removes specifications intended to address specific lot conditions. For this reason, any stock plan you purchase should be reviewed and adjusted to address your local codes and conditions.