This question is a bit different than the typical we are moving our server room to an off site location or we are moving the whole office to a new building.
Management wants to add some more office space and to do so they want to move the server room to another location. The server room has Verizon smart jacks, a few servers, PBX and all the office network drops go into this room. I'm going to go over there to scout out an alternate location for the equipment because that is still TBD. This sounds like quite a pain since the Verizon equipment for our MPLS will need to be moved (never done that) and the office jacks will need to be re-run.
How do you handle the jacks? I was thinking of keeping them in the same location and having new wall plates put in with half the ports going to the current location and the other half to the new location. Or do you think that 40 drops could just be done over the weekend so the old stuff would be ripped out and replaced with the new? Currently the wiring is a mess so this could be a blessing in the long run.
Option 1: Lock yourself in the server room and refuse to come out until management change their minds.
If that's not feasible, you've got a few problems to consider:
Cabinets: Easily overlooked: Make sure your rack(s) (if you have any) will fit in the new room and through the door (or in the elevator), or factor complete disassembly/reassembly into your time estimate.
Power: Do you have these servers on a separate circuit? Will you need to re-route that power to the new location?
Environment: Do you have separate AirCon for the room? Are you going to be able to route the pipework and ducting for the new location?
PBX: These are usually portable enough. I'm in the UK, so things may vary a little, but it's probably just a matter of getting your provider in to route the incoming lines to the new site from the distribution board. Depending on your service contract, you might have to get them to move the PBX for you, though.
Internet: As with the PBX, you'll need to cooperation of your provider, here. They'll have to come in and move the lines to the new location. Moving service terminations needs the cooperation of the provider, usually. They get upset if you mess with anything before the demarcation point (usually the smartjack/NID/Distribution board).
Structured Cable: If I understand your question, you want to keep the ports you have already and add more to cover the new office space, while moving the whole patch panel to the new location. Consider that you'll probably have to move most of your furniture and disconnect most of the computers during the work. If you have a raised floor, the installers will need to be able to pull most of it up in one go, which is a massive upheaval in an occupied office.
If at all possible, avoid having a split setup with ports terminating in two different locations. It's a pain to manage and, with only 40 ports, it's not a big enough network to necessitate it. Besides, I would assume you need to surrender the existing space entirely, hence the need to relocate? Leaving ports there is likely to be unsecured and ugly, though that depends on your office layout.
Make no mistake, this is going to be a disruptive job. To make it easier, try to get management to sign off getting stuff like AirCon and power installed in advance. Ask your providers if they'll run new terminations up to the new room, first, before switching over on a named date. If the structured cable run can be done over a weekend (~40 ports should be feasible), then enlist the help of the staff in prepping the ground on the Friday afternoon. Get them to ensure they're shutdown and unplugged and maybe even move their own kit to a store room (there'll be breakages, naturally.) and help with the furniture.
I still favour option 1, of course, but good luck. :)
If you can afford to hire a professional, I would redo the whole wiring.
I faced the exact same situation and ended up having two rooms that had equipment and cable drops...that was a pain.
Try to centralise your telco and IT infrastructure as much as possible.
My advice: centralize. This is actually a great opportunity to do things right - if you can get the buy-in and money from management. Leaving network/telco drops scattered about in different rooms absolutely sucks due to things like having to provide backup power and cooling in multiple locations.
I was involved in a big project at a company a couple years ago to do exactly the same thing. In that case we had the budget to actually consolidate three small server rooms into one. It was definitely a disruptive process, but not terribly so. A key point is that you can (and must) get the telcos to come in ahead of time to prewire everything. Then the switchover can be done over a weekend and mainly involves moving your hardware into the new server room location.
This is also a wonderful time to label everything and clean up your wiring. A big annoyance of the move I made was that a number of the rackmount servers we moved were actually sitting on shelves in the old racks and not properly bolted to the racks. We didn't think about that enough and ended up doing the same thing in the new room. I wish in retrospect we would have taken the time to find rack rails for all the rackable devices.
Also note there are a lot of ways you can save money on moves like this, but the tradeoff is usually your time. Management will be happy to not pay an external wiring contractor to rewire your network drops. You will not, because that means you are the one poking around in grungy drop ceilings and such. Think very carefully about the compromises you are willing to accept. In my experience much of the work of a move like this is completely hidden from people like the CEO. I was happy with the work I did on that big move and my immediate management understood how much work it really was. The C-level execs had no idea, however and there was a perception that other IT projects were overly delayed during that time - because they didn't understand how many late nights and weekends we spent. Ultimately I think technical moves and the associated planning can be very satisfying but might not be that great for your career long term. This is more of an opportunity cost issue as you are spending time working on a move instead of on more visible project.