Not sure if this is a duplicate of a recent post, but you really have to ask yourself if this is worth doing at all in a warm climate. Far more cost effective to concentrate on air sealing and good insulation in the attic and basement.

As for the foam over stucco as used in Europe, what I've seen in photographs is incredibly ugly - looks like the worst of Soviet architecture as practiced under Stalin. Then there's the hugely labor intensive process of adjusting all the exterior trim.

Unless you are faced with very high electric rates for summer air conditioning, wall insulation under your conditions strikes me as totally unnecessary.

Not familiar with what you're looking for. (The video is not available at the URL provided.)

But instead of adding two more layers of material, consider removing the existing stucco board (or is it actual stucco), dense pack cellulose or foam, then finish with stucco or other siding.

However, the whole project makes little sense in terms of payback in your moderate climate.

Here are the IECC 2012 requirements. You're in Climate Zone 3.

Thanks for the responses. Winter is not super cold, but it is still cold. We have night temperatures around 40F, and for a short period in winter, it may drop to 32F. Walls and floors feel pretty cold to touch. But I got your point about checking air sealing first. This might be the first issue we need to target, as we often feel a cold air draft close to floors.

Could you remove the interior perimeter walls, install insulation and then put in new drywall? It would be a good time to upgrade the wiring as well.

I lived there for 13-14 years. Had an appt in Mt View uninsulated. There was a fairly thick cold boundary layer next to the walls. Touch the wall with your arm horizontal and your hand would be cold but shoulder warm. The layer was about 12-18" thick - don't remember exacty tho I did measure it. I'd bet your ceiling is not insulated either cause I had a house in old Sunnyvale same age as yours and it wasn't.

I'd guess the draft you feel is from a convection current with cold air flowing down the walls rather than a leaky house. Just a guess.

I'm in the next zip over. Original construction quality here is very low. Home values are sky high. It pays to do the job right here unless you are flipping. Either add a layer on the outside and redo all the windows and doors, or rip out the walls inside and insulate properly. I hate the interior wall texture here, I would rip out the walls and put in nice smooth ones.

I think the swiss cheese method is useless because there is no way of knowing if everything is really plugged up and the foam is truly filling the cavity.

Yes. Dryvit Stucco and a product called Sto can be applied directly onto ridged foam insulation.

Yes they are available in the US and have been used for many years.