We are a small architecture firm currently subletting office space and plugging into the existing office network for internet/printer access etc.
We are needing our own shared data storage just our few computers, is it possible to connect the NAS storage (such as the WD DX4000) via the standard network ethernet ports and set it up for our computers from there without needing to change any settings on the main office network?
Also, we will have people working remotely in the near future who will need remote access to files, can this all be set up?
Yes. You should be able to plug it directly into the existing LAN and share the files. Note that EVERYONE on that network will be able to see the NAS, so ensure you understand the security settings and enable access only to users from your business. There is a remote access feature but that option may require you to open ports on your existing network, which is a change in your existing network.
A better setup which you should look into for the future (immediately if you concern about other users within the office accessing your data) is to have a separate LAN for your business. This does not mean another physical network. Ideally, you should be able to setup a VLAN with another private IP block for your business only. Each business in the office should be on their own VLAN. Shared devices can still be enable across VLANs, while other other peripherals on your VLAN remains private. If VLAN is not an option, then you could add a router to the existing network and connect all your PCs to that router. Both options will offer better security and allow you to take full advantage of the NAS, such as adding it to your domain. These options will still require opening ports to enable remote access.
You should also contact WD with your questions as you are a potential customer.