So, as I was recently playing flood, I noticed somebody was complaining about another one building close to them, and tried to "threaten" them by writing crap in the chat. Building near them is allowed in the spawn, of course? The person who was complaining about LemRz pushed his boat away with a prop, and given the engine of GMod, it became unusable. I don't want to make a ban report on this person, because I don't have proof of him proppushing (I usually never take screenshots, kind of not second nature for me). In the image, LemRz is in the corner, and eikooc is the one with the toolgun. I know that just saying names like this without hovering over can't be believed but I wasn't able to get more proof. http://steamcommunity.com/sharedfiles/filedetails/?id=472164085
Building close to people in spawn is fine. Theres really no rule against it. Though if you're going to build next to someone, you shouldn't intentionally interfere with them as this would break our rules. Though I have seen people who will build massive boats and ask other people to move because they feel the need to take up the entire spawn. In which case I don't think you should be required to move. TLDR: While not against the rules, it "can" be considered minging/sabotage ect. It's up to the administrator to decide but generally a free for all.
If I see players building directly next to eachother to the extent that it can interfere with another person's building (They may want to place props there) I usually ask the players to move away from eachother.