Making (bivy) tent similar to Marmot Home Alone

Hi!
I'm hoping to make a bivy tent along similar lines to that of the Marmot Home Alone Bivy Tent, but with significant ventilation to reduce condensation, but still weatherproof!
Has anyone got any ideas?
Cheers
[img]https://goo.gl/images/81gPEf[/img]

Bump

I don't have any hands on experience, but have you checked out Henry Shire's original tarptent instructions:

https://www.tarptent.com/tarpdesign.html

It doesn't have the hooped ends, but if I was going to attempt making a tent I would start there.