Controlling heat gain on western-facing glazing? – GreenBuildingAdvisor

Hi GBA,

Trying to prevent solar heat gain from cooking interior spaces through a large amount of west-facing glazing and hoping to pick the collective brain here for suggestions.

Notes:

* Two gable forms facing west, one the great room and one the primary bedroom, both connected by a glass breezeway with lift and slide doors opening on to a stone patio – diagram attached.

*All views are due west.

* CZ6, western Montana. Cold winters, hot(ish) summers, lots of sunny days, very dry, ±4,000′ elevation.

* 1′-6″ overhangs currently. I ran some daylight simulations, and you don’t really start getting appreciable shading till the overhang gets beyond 6′ – so simply blocking the light before it’s a problem doesn’t seem like an option.

* Recessed, pocketed, automated shades throughout. Obviously this is problematic/not possible at the triangular gable glazing.

* Not opposed to losing that upper glazing at the gables.

* Pushing hard for triple pane windows. I have a good local rep for guidance on coatings, etc but any suggestions welcome. Seems like triple pane + a good glass spec might be the only options for really controlling heat gain here?

* There will be a mechanical engineer designing all the systems.

* Still in design, plenty of time to pivot.

(As an aside: this is a lot of glazing, and it’s a vacation home. Not exactly “green” but I am trying to make decisions about assemblies and materials that will meet the client’s goals while doing the least harm)