Will taxes skyrocket if we add a floor?

Q. We want to add a floor to our one-story home, and also want a den addition. Will our taxes go up a lot? We know they’ll increase, but we’re concerned they’ll be too high for us to do the addition.

A. Before the reassessment was done around 2003, there was a straightforward method of figuring this out. You’d contact the county assessor’s office, give them the section, block, and lot and determine the increase based on a multiplier -- a number based on a hypothetical square footage. For example, you could ask what the increase would be for a 100-square-foot addition, divide the increase by 100 and get the fraction they used to arrive at their number. Then you could multiply by the real number, and add 10 to 15 percent to account for differences in the assessor’s evaluation and the yearly increase in taxes we all take on, and get a fairly accurate idea.

Now, thanks to a very confusing, completely subjective system, even the assessor doesn’t know the answer to your question. Tax increases are based on property value, and each property is compared with similar properties (in their opinion) in your area. They look at what has sold recently and what the size and cost were, for comparison. The system is really determined by all the people involved in a home sale and what they could get for the house or what they appraised the house for. The current system actually discourages home improvement and home sales, and encourages illegal construction, safety risks and code violations. So the answer to your question, in all honestly, is I don’t know.