If there is one house it is clear in any form, but if there are several houses, as you point out, then it can be ambiguous. "John, Mary, and my houses" would be different than "John's, Mary's, and my houses."

That being said, "Our houses are all on Oak Street," tells us little about ownership. I get that you are not trying to avoid the rule, but to avoid ambiguity, which is the reason for rules, we need to provide additional information.  

Possessive-S/apostrophe in a list, including the first and second person
I have some extra bags of spring roll wraps. Am I able to freeze them and if so how? Also would I be able to freeze them once I make spring rolls. The spring rolls would contain : 


shrimp
pork
carrots
mushrooms
onions
eggs
vermicelli noodles 

