Effective planning a layout for the best utilization of space in an office requires a lot of detail, an infinite amount of time (it seems) and more information than you originally thought you needed.
 Here are five (5) simple tips:

1. Create a standard for individual work stations.
   Make the workstation functional.
    It is important to make sure that the materials a person uses on a daily basis,  i.
   e.
   papers, binders and a computer have a planned amount of work surface and adequate storage.
   The final layout is a footprint for the workstation.
   Create a minimum number of standard workstations.
   Design for the ultimate job function not the person.
   The person may leave the job but the work still needs to be done.
    
2. Measure -  Measure the height x length x depth, of each  piece of furniture and equipment that is to occupy the space and each  piece of  equipment to the nearest 1/8 inch.
   Field measure the length, width and height of the space to space to be occupied to the nearest inch.
   
3. Include a circulation factor -  Allow for a percentage of space to be used just for walking around.
   It is usually an additional 15 - 20%   of the space you have calculated for the workstations, general use equipment and storage.
   The question to be answered "How do people get to and from their office starting at the front door?"
4. Total Space Requirements - Use the footprint of the workstation's plus the area required for equipment plus the area required for circulation to determine the total amount of space needed.
   
5. Check your results - If this doesn't work on paper,  it will not work in your office.
   

It is a very detailed job and worth all the time and effort.
Ultimately you are saving an enormous amount of money by using the information to have a smooth move.