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Reducing WWR to 40%: which approach?

When you have a lot of glazing and are following ASHRAE Appendix G, you might have to reduce the glazing area in the baseline model to be no more than 40%, respecting the proportion of the proposed model for each orientation.

I see two ways of doing this:

  • Add windows on all exterior (non-adiabatic) walls, and set a WWR ratio by facade. This would be akin to using the OS/sketchup measure "Set Window to Wall Ratio")
  • Downsize your existing windows in order to be at 40% WWR overall

I'm leaning strongly towards the second option, but I might have missed something.

What do you say?

Reducing WWR to 40%: which approach?

When you have a lot of glazing and are following ASHRAE Appendix G, you might have to reduce the glazing area in the baseline model to be no more than 40%, respecting the proportion of the proposed model for each orientation.

I see two ways of doing this:

  • Add windows on all exterior (non-adiabatic) walls, and set a WWR ratio by facade. This would be akin to using the OS/sketchup measure "Set Window to Wall Ratio")
  • Downsize your existing windows in order to be at 40% WWR overall

I'm leaning strongly towards the second option, but I might have missed something.

What do you say?