I am interpreting this question as "How would modern technology and design have developed in this world, and how would it look different?"
You mention architecture more than once, so I'll start with that. Seeing as not everyone has legs and not all legs bend the same way, stairs are not going to be widespread. Ramps seem the obvious replacement, but there could be lots of different kinds of ramps. Smooth, flat surfaces would accommodate the halmis, while the petos and maybe the keretas would prefer a rough, gravelly surface they could dig into, and lykos and humans might want a grooved, bumpy one that sort of simulated stairs without providing too much resistance to a halmas. Since ceilings have to be high to accommodate taller folks, the ramps will probably need to twist and turn in order to reach the height of the next story up without taking up way too much space on the ground plan. I'm imagining modern buildings will have ramps fashioned from long sheets of metal, probably stainless steel or hardened aluminum alloys, reinforced by a web of metal wires all wound around a series of poles in a corkscrew shape. Of course, besides ramps, you will probably also have elevators, and more sophisticated ones - the elevator probably would have been invented and normalized far earlier, and would have developed to be a quick, smooth and convenient ride.
In terms of technology, the clothes in you character designs suggest a modern society, so I'm assuming electricity, computers, and wireless technology are all in play. I think computers and so on would still exist, but their design would be bigger, bulkier, more like the futuristic computers we imagined in the 80s than the sleek, smaller designs we got. This would allow it to fit more hand sizes and function in spite of claws, excess moisture, hair shedding, etc. Touchscreens almost certainly wouldn't be big outside of human societies, and may not even have taken off there. Instead, I think voice recognition tech would have been prioritized from early on. Handheld computers would exist, but instead of being smartphones, they would be headpeices somewhere between the Dragonball Z power reader and Geordi Laforge's visor - a screen and an earpeice, programmed with a speech interface that controls the screen.
That's how technology and architecture as we understand it might be molded to fit a society that wanted to accept all five such peoples. However, what tech and design would they have developed for themselves? I can't help but imagine that, in buildings made only for the petos, there would be little pegs sticking out of the walls instead of stairs or ramps or even furniture on the floor. They would jump-glide from peg to peg to go up in a verticle building, and perch on a peg on the edge of the room rather than sit in a chair in the middle. Petos houses may not have multiple stories or ceilings at all besides the roof, and some may lack even that. Similarly, Lykos and Keratas probably go in for rugs and pillows to lie on rather than chairs or stools to sit on, and. Keratas in particular would have normalized some kind of scratch toy in their interior design, something a person could play with and work their claws on while they talked. Fidgeting is probably way more acceptable in their cultures, while standing still is viewed as agressive behavior, something you do if you don't trust people. So, their room layouts would be wide open and full of stuff to do. Meanwhile, halmis architecture is going to be completely alien - underwater houses you swim through, completely different building materials, and as a result, probably no 'front door' or 'windows,' but a more free and open design with multiple entry and exit points. They would be used to thinking of their homes as 3D spaces and not flat rectangular room layouts stacked on top of each other.
This may be neither here nor there, but perfume is going to be way more developed, and a much more powerful aspect of fashion. The Lykos probably have an extremely developed sense of smell, and base their first judgements of people off what they smell like more than what they're wearing.
I hope this addressed some of what you wanted, and that it was helpful.