Double wedding and vow renewal

Interesting question. The first idea I had was have one of the ceremonies, have cocktail hour, then have the second ceremony. I would probably have the vow renewal as the second ceremony if it's short and sweet. This will work only if the ceremonies and reception are at the same venue.

Thank you we were thinking of starting with the vow renewal " what a way to start a beautiful wedding to witness 2 people whom have been married for 20 yrs renew their vows to each other. she said she will watch from another room. Her groom will already be upfront. We really dont' want the guests to have to get up and then sit back down again lol

I don't have much advice, I just wanted to say that I think this is really sweet.

I would put the vow renewal first. Truth is, a wedding is more "exciting" for the guests than a vow renewal is. Your renewal is absolutely important and meaningful... it's just that a couple only ever has one wedding and it marks the beginning of their married life, whereas a couple could have more than one vow renewal and their married life is already well underway. I think by putting yours first, your renewal ceremony would be a beautiful prelude that hypes people up for your sister's wedding ceremony. Putting it second risks having it seem like an afterthought, which would be a shame.