Zola Window Install Detail – Is the Alum Angle Really Needed? Anyone installed Zola? – GreenBuildingAdvisor

Hello,

My friend is in the process of building a house in Montana and I am helping him with the drawings/details. He is working with Collective Carpentry for the prefab enclosure and Zola (all aluminum) for the windows.

For background I am a licensed Architect and CPHC.

Regarding install of Zola window: In their detail they have an aluminum angle backdam screwed to the window which has a very strange interaction with the sill material. They are the only ones I’ve seen with this angle, and it says its to eliminate the clips at the sill.

My questions are:

1. Has anyone installed Zola windows before, and did you install the aluminum angle? If not, what did you end up doing?

2. Whats so bad about just using clips at the sill? This is how we install all the other window manufacturers we have worked with.

3. Zola shows backer road and sealant at head and jamb and mention this is a crucial detail (vs tape or something else). We’ve hit passive house cert with tape at the window in the past. Am I missing something?

Thanks in advance, appreciate any insight.