You simply have to measure buildings and office space for your clients today. You can't rely on what other people tell you the square footage is, and you can't rely on building plans and plat maps either. I've encountered situations with both building plans and plat maps where the information has been inaccurate. Measuring the building yourself is the best way to determine whether or not the footage the building owner is quoting you is a reasonable approximation of the truth.

In over 20 years in the commercial/industrial brokerage business I never once measured a building that was larger than the size I was told it was by the owner or listing agent. However, I measured plenty that were smaller than what I was quoted by these people.

Once I was looking at a building that was listed by another agent. It had recently been vacated by a major soft drink manufacturer. It was an older building and was a real hodge-podge of different, non-symmetrical sections with a partial second story and a partial basement.

The square-footage on the listing agent's flyer for the property stated that the building was 140,000 square feet in size. However, when I measured the building I came up with a building size of approximately 120,000 square feet. I called the listing agent and told him about my measurement. I asked him how he came up with the footage of 140,000 square feet and he told me that he had seen it on another brokerage company's flyer from 20 years earlier. He figured that the footage from the flyer must be accurate.

The point here is that you can't trust the information that other people give you when it relates to building and office sizes. They may think that their information is accurate when in fact they are misinformed. If you are truly someone who strives to be the best at what you do, measure all buildings and office space yourself to make sure that the best interests of your clients are protected.