There is a series of metrics which is invaluable for analyzing the efficiency of any office space, both existing and planned spaces.
At first glance it may appear simple to list all the spaces needed, along with their respective sizes and arrive at a total square footage requirement; however, additional space should be allocated to account for hallways and circulation paths within your space. This can vary dramatically depending on how efficient a layout that can be accomplished within a given building footprint .

Allow room for growth. Optimally the new space should be sized to accommodate all the staff projected through the midterm in the lease, e.g. 30 people are expected on move-in and your firm should grow to 50 by the end of the lease.
Once you choose your top 3 spots, MSA will then get busy creating a test fit to see which space works best for your new HQ.

A little up front analysis and planning, through the help of a professional architect with experience in office planning, can go a long way in laying the necessary groundwork for a smooth transition to your new office.