The owners of this Harwell Hamilton Harris house, an exemplary modern house from 1940 designed by the celebrated disciple of Wright and Schindler, need to add a bedroom and office, as well as a bathroom, but didn't want to disrupt the original house they so love. Our answer is to excavate underneath the house and add a lower level which will still open up on the back hillside. A new stair and reconfigured entry area creates the connection from the existing house to the lower floor. By adding the lower floor, we are able to create a connection to the outside that didn't exist before. Other parts of the design will include a new master bath and closet, and reconfiguration of all outdoor patios and terraces to make this small house livable for a family with two kids. Harris designed the house using a strict grid pattern whose module will inform the new spaces too.