Starting with a month of paperwork

Submitting plans and obtaining clearances is the starting point for a project like this. Both the City of Lake Forest and my neighborhood homeowners association (Portola Hills II) required detailed plans.

I found that creating a custom-scale grid in Microsoft Excel worked just fine to craft the plans.  I essentially turned Excel worksheets into "graph paper" -- with each little square equaling one square foot.

My starting point was scanning in a 20-year-old floor diagram given to me by a neighbor whose home is the mirror image of mine. This came from the builder's original sales brochure. I simply flipped the drawing electronically to match my house and began cleaning it up and labeling it for my purposes.

The new bedroom will occupy the central, rectangular space shown in the left image -- directly above the dining room.