Hi Andy:
What IDS has done in the past is:
1. Provide new horizontal saw-cuts in the brick inside and out
2. Insert steel angle lintels inside and outside in the saw-cut slots with through-bolts. If your new parapet windows are continuous, you may want to do this in sections.
3. Remove existing brick below the new angle lintels, install steel posts.
I don’t know if the architect will permit a steel angle lintel exposed on the outside, so that may need your design attention.
Respectfully,
IDS Group, Inc.
Bob Freeman, AIA, EIT
949-387-8500