The Scenic Porch awning fits into the awning channel along the top only (about 3 feet). The sides are simply pulled down against the van and pegged, so there is no seal as such, but it's not intended to be a luxury porch. It is extremely functional, we get two chairs and a small table into it, it's great for changing out of wet clothes, it hardly weighs anything and I can put it up in 7 minutes. We use a "proper" awning when we are staying for over 3 nights. Definitely recommended for walkers, dog-owners, etc for short stays.