The single slider is going to be less expensive, but single hungs are typically more airtight than sliders, and have a better sill design. For the craftsman style, if the price difference isn't a problem I'd go with the single hungs.

Good advice above. The slider will be cheaper, but the SH's will be more efficient.

You would have to compare the air infiltration numbers on each. Some brands have post same numbers for the slider and single-hungs. If you take 2 single hungs with an air infiltration number of 0.04 would that equal an air infiltration number of 0.08 for the opening? So if you went with Gerkins single hungs(0.04X2 windows) vs their slider(0.04) you'd be much tighter with the single-hung? The sliders would also be better for egress issues in bedrooms as well.

The two single hungs sure would look better for the craftsman style home.

Todd,

The air filtration numbers would need to be the same.

Adding them does not work in this case.

WOW, how come?

They are based on sq/ft numbers.

Ex. 2 single hung windows with air infiltration rates of 0.05 at 10 sq/ft will collectively leak 1 cfm of air at the test conditions.

1 sliding window with air infiltration rate of 0.10 at 20 sq/ft will collectively leak 2 cfm of air at the test conditions.