Hi Karen,

Do you mean the wall length or the wall thickness?
a 8" wall seems too small for a house or a panel?

If you meant the thickness

- Draw you walls--> put the walls alone in a tab (no floors, no roofs, etc)(If you are in the floor tab (or electrical, etc), you will see a small arrow at the right of the name. By clicking the small arrow you have the option of viewing or hiding other tabs. Just uncheck the names of all the other plans) --> Edit--> select all--> all the walls will be selected--> In Platinum V4.5.1.--> right click--> exterior walls properties--> change the thickness
In Platinum V8--> Properties bar--> change the thickness (see image attached)

- You can select all the wall handles (see image attached) and follow the procedure above

Hope this helps

Patricia