Thanks for sharing, Steve.

I did a very similar project but on a nice large apartment complex. The situation that occurred was the tenants not closing the outer window. We would never have thought this would happen. They were lazy and would leave the exterior window open in snow and rain. This looks like this is a 3 decker with tenants and I assume there were hopefully no problems. The windows appear to interior extension jambs between the windows. I still think it is a good solution.

Excellent information Steve! Can you explain how you handled the air infiltration/insulation for attic? Another video??

In your opinion from a material cost and performance perspective does it make sense to use less than premium double-glazed windows and then install retro storm or triple track storm windows either in or outside with what is basically a double envelope system in new construction

Considering something similar, ~130-150 year old early-victorian, but want to preserve the window look from the exterior. Thinking about 2" rockwool exterior + rainscreen, adding 2-3/4" window bucks to new siding. Interior would eventually get new custom made inswing windows.

Furring strips go over the original siding then? And there is no vapor barrier membrane inside the wall? I've never seen this option. Thanks!

Did the neighbors complain about the chemical release into the air near their homes, especially as the adjoining homes in an urban location are closer than in many suburban lots.