|All good answers guapo|
If I might add a few things:
is it okay to use seperate switches for each room considering future upgrade options (in this it case it will be 2 x 48, 48, 48, 48, 4 port switches.)
You shouldn't have to do it on a room-by-room basis. Most modern buildings are designed around networking and have centrally located "electrical closets" (aka "wiring closets) where all the network connections for an area of the building terminate. This is the closet your switch (or switches) would be since that's where all cables terminate.
Otherwise is the standard is to take the full number of PCs & Server and then decide on the number of switches which would be 178 and thus 4 x 48 port switches.
There is no "standard" The rule of thumb is always, "allow for growth" Simply put, you'll want to have unused ports available. When you run out, buy another switch (or switches as the case may be).
Is 48 port switches the maximum you get?
You can get 96 port switches. We just bought some that are 10 GB capable on the backplane and across the fibre optic (uplink) connections. But these cost us around $10,000.00 so whether or not you'd use equipment like that would depend no your budget and need.
The main reason for my above question is we have to show the network topology for each room and I felt it would be easier to show by having seperate switches.
Your topology is going to be "mesh" across the board. There's no need to show it room by room. In a typical, larger, network you have all your switches connected on what is called a backbone. In our case, it's fibre optic cabling connecting our wiring closets (and thus, their switches) to our dual, redundant, core switches. All clients then connect to the switches in the closets. Therefore, our closets connect in a mesh to the core switches and the clients mesh to the closets.
At what point do you need more than one server.
Assuming you have the necessary budget, I would never go with less than 2 domain controllers. Your primary DC and a redundant DC. One should always try to keep the load on domain controllers to a minimum so I would not load any other services on the DC's.
Let's assume you're going to do email with Exchange Server. That should be on it's own server.
Assume you will have a database application of some kind. That's another server.
Add that up and you have 4 servers.
In the end, the number of servers you require is dependent on need and budget. If you can only afford one server, you could do all the above on a single server. But, that server would be carrying quite a load and if it failed, you're entire business shuts down. Thus the need for redundancy and more than one server. If you have multiple servers and the primary DC fails, the redundant one takes over and there's no downtime to end users.
If the Exchange server fails, the database and domain keep working but all clients lose email until it comes back up. If you lose the db server, no db but you do have the domain and email.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.