Disk space question

I have someone telling me that he can't install a copy of our webserver on the dev server I set up for him because he doesn't have enough space. I'm a windows infrastructure person and am just learning Linux. but I don't think he is right. In my thinking, space available on / would mean space available anywhere. Am I right?

If I have a Linux server with

df -h
/dev/mapper/VolGroup00-LogVol00 955G 28G 928G 3% /
/dev/mapper/VolGroup00-LogVol03 5.0G 3.7G 1.4G 73% /var

Will I have space available to install a drupal webserver into /var/www ?

or do I need to add drive space to /var ?

Thanks