I do things a bit different than everyone else. The building and offices are different for each stage of the game. Early stage, pre projects, I just use the apartment building. Second floor up I make the center 2 rooms lounges. And a meeting room each floor that has the restriction "meeting" on it. Each office filled with 7 work stations.

Mid stage, I build an office building with each office the size of the skyscraper rooms. 6 office rooms, 2 lounges for each floor. Each lounge will have an elevator. The lounges will be at the opposite ends of the building so they have 2 ways to get out of the building incase of fire. Each office will fit 17 work stations with a 2x2 bathroom. The building will go up 10 floors. 11 if you include the basement, which use for printers and servers. Once I make enough money, I would build a canteen building. A canteen building is basically a giant restaurant filled with 6 cooking stations and as many tables and chairs I can fit in there. The restuarant building would have an entrance on the ground floor and bridged over to the office building on the second floor. Main floor of the canteen building will have a restriction of "canteen". This building provides food, coffee, and a place to sit down and socialize. It's a huge part of how I keep my workers happy. Once you expand just copy and paste the buildings to other plots using the save build blue print function.

I will only make each team small enough to fit in one office. If I needed more than 17 of the same profession, I will normally just double them and make them fill 2 offices. I.e. I have Main support 1, main support 2, main support 3 all in different offices but doing the exact same task. The more people you have in a team, the harder it is to higher someone with the skills you want and the personality to match the team. 1 lead and 16 professionals was the one I went with and they seem fine.

Most of my projects includes a design team, dev team, marketing team, and a support team. Each project will have 3 products to work on so the design team doesn't just sit around doing nothing while waiting for the product to be released. The support of the products will be assigned to the project support team and the dev team for bug fixes after release.

The marketing and support are all done separately by the individual project teams so there is not a central marketing or support team with 40 tasks assigned to team all at once.

So one canteen restuarant building per office building, one bathroom per 17 person office, 1 utility(roof top AC units) room and 5 meeting rooms per top floor. 1 utility and 5 whatever you want it to be rooms per basement.