Large variance of SMs together

[kirbwarrior]

I've been working on a city in my setting for awhile now and I'm having some trouble imagining things. Here are the core concepts that I'm having trouble with;

There are 9 races (might be more, but this is the focus). One for each SM from -3 to +3, then one each at -6 and +6.
Breaker Vault is an enormous cityscape. There are many methods of travel, but it's assumed to be a week's travel to get from one side of the city to the other.
In this city, all the races live together. It's largely the melting pot of the world. It's less so in other places, but then any other place doesn't get much bigger than "town"

How would buildings be built for such a place? Roads? I like major roads being almost freeways (maybe even above the city) that anyone can easily traverse. Shops could largely be outside stalls so anyone can access them. Apartment complexes could be based around the biggest race, with smaller races having complexes inside the giant complexes (an entire -6 "colony" could exit within an apartment big enough for +6)

I'm still thinking on exact details for each race (largely, the -6 will probably be faeries with Flight). The setting is close enough to TL4^ due to magic. The "simple" answer would be that the city just forces everyone to the same SM, but that seems like a boring solution. I would like the "chaotic" feel of many different sizes having to live together, since I want a "civilized chaos" feel to the city (guild rivalry, alchemy experiments going wrong as a daily experience, etc).

The ideas are vague but I wanted to solve the logistics issue before trying to worry about extra issues that can crop up from racial differences (for instance, there might be a race that talks using Mind Sending instead of voice). Really, a place where a SM -6 faerie, a SM +0 human, and a SM +6 titan can live together is the crux of this, since the intermediate sizes would be less of an issue.

Any help would be appreciated. Thank you ahead of time.