My home was built around 1910. Since insulation wasn't used then my wall are not insulated. I am planning to pull the lathe plaster down and put up new drywall, upgrade electric, telephone and such. My problem is that I have quite a bit of air infiltration thru the exterior walls. I know the best solution would be to use a housewrap but, the outside of the house has a layer of wood siding, then a layer of asphalt siding, then vinyl siding. It would be a major undertaking to strip all that off and put on housewrap. What would be the alternatives for sealing against this air infiltration? Sprayed in foam I think would do this but is a tad bit more than I can afford at this time.

Any help anyone could give me would be very much appreciated. Thank You