Happy Holidays,
Zone 5A
My son purchased a old Tudor style 2 story home built in 1906. I believe you call this balloon framing. Exterior wall studs pass through floor and sit on the mud sill plate. From inside out is plaster and wood lathe, some horse  hair, 3″-4″ open space, 1×6 nailed to exterior of studs,  and brick. Would this open space continue to attic? One section of attic is very large, you and play basket ball up there. Only vents  in attic I can find are what appear to be windows 16″x48″ and found a old note that said to close in winter. Can I fill the stud cavity’s in basement with insulation? Attic insulation is 24″ deep. Also some openings in attic along outside roof line. Any suggestions appreciated.