Admin Loading Times

I’ve got a number of sites which I’ve built using wordpress. The sites runs fine and quite fast when I view it on my home computer and on various other computers connected to the internet. However the problems I face are absolutely crazy slow loading times when I try to access the wordpress admin in my office.

Why would the location make any difference when all other non wordpress websites I’ve built run fast. The only time I get slow response times is when I’m logged into a wordpress admin area.

Another person who has an office in the same building as me has the same issue when she tries to access her wordpress admin.

Any ideas on how this can be resolved?