The exterior walls are not the only problem. There are a number of ways that the tax data may be a serious over or under-estimate. When a home is being measured for tax purposes, no one will look into the specific layout of the house to alter the measurement accordingly. This creates problems in a few different home types.
For example, if the living room of your home has high ceilings and a gap in the second floor above the living room, all of that empty space will be counted as additional square footage in the tax data. They assume the second floor is just as large as the first, but sometimes it isn’t.
On the other hand, tax data measurements may also be too small. After a homebuyer builds an addition on their home, it may be some time before the tax data are changed to reflect that. The same problem may happen after a mudroom is insulated, a patio is enclosed, or a loft is extended. The current homeowner may not be the person who made these changes, so you can’t assume you’ll be alerted to them.
If the square footage measurement is smaller than the actual living space of the home, you’re missing out on a powerful selling tool and, potentially, more substantial offers.