Most importantly, you will need to find a nearby expert to help you with this project.
The good insulation options are all installed with expensive and difficult to operate truck-mounted systems. I recommend starting at www.BPI.orgor searching for an energy auditor here in GreenHomeGuide's directory.
I think dense pack cellulose (or fiberglass) can be a good option for "drill-and-fill" depending on average moisture levels and indoor air quality goals.
- Also, there are many new expanding foam options that could work well.
- If using expanding foam, you need to make sure the expansion pressure will not crack the Stucco.
- Lastly, remember that you will need to budget for the patching of two holes per stud bay (so probably at least 200 holes per home) and painting wall-to-wall for a nice finish.
Ideally, you are also able to install some rigid foam board underneath the Stucco to create a "thermal break" (the wood framing has very poor insulation value and is about 20% of your wall surface in an older home).
The foam board should be paired with a weep screed and other best practice water managment systems.
For more information:
Read "I want to add wall insulation to my 1920 home. I have two locally available options -- Icynene and Tri-polymer foam. Can you advise me?" a Q&A answered by Alex Georgiou.