- cost of double vs triple
- energy use difference (ROI period?)
- air leakage
- emergency egress
- minimum dimensions
- 20" wide, 24" high
- net clear opening 5.7 sq. ft
- 44" max sill height
- minimum dimensions
- intruder resistance
- picture windows seal best, followed by casement and awning
- high end vinyl windows are good, cheap / contractor grade vinyl usually isn't
- insulated fiberglass frame is most durable and least maintenance.
- u-factor: lower u-factor = higher insulation, lower is better.
- 0.30 is mediocre, less than 0.25 is good
- Solar Gain Heat Coefficient (0: blocks all solar heat gain, 1: passes all solar heat gain)
- ~0.30 is typical, less is better in summer, worse in winter.
- South / West (sun facing) windows need low-e glass (SGHC closer to 0)
- Visible Transmittance: 0 to 1, higher is better.
- Air Leakage: 0 to 1, lower is better.
- Condensation resistance: 0 to 100, higher is better.