Selecting the right metric for looking at your portfolio makes a big difference in your ability to identify good and bad performance. Let’s start with the assumption that obtaining good data isn’t an issue – yes, I know, this is never the case but it gives us a starting point.
The similar metrics Square Feet per Seat and Square Feet per Person seem to reflect the same point of view on the surface but in reality have dramatically different meanings.
1. SF per Seat is an indication of the space efficiency of the building layout. It is simply the total count of seats that people sit in divided by the square feet of the building being evaluated. A highly efficient building may be at 150 SF per Seat. A poorly designed building or research facility may be above 500 SF per Seat.
2. SF per Person is an indication of how well the space is being used within a building. It is the total count of people assigned to a building divided by the square feet of the building being evaluated. A building with telecommuting and seat sharing could be at below 100 SF per Person. A poorly utilized building with a high vacancy rate and poor space layout may be about 750 SF per Seat.
From an analysis standpoint, SF per Person is a far more sensitive and telling metric. In one number you can identify operational and design considerations within a space. A space that is a poor space design but it well utilized will display as a lower priority for evaluation than a site with decent design and decent utilization.
Of course, obtaining accurate headcount information is a very difficult thing for most organizations. But hopefully the value of the metric provides a good reason to begin collecting the information.
The point of this is that the metrics you choose to understand your portfolio will tell you different things and some will be more telling than others. Focus on what’s important to your portfolio and your organization’s strategic goals. Sometimes the most common metrics give you the least amount of visibility to what is actually going on.