I have a sunroom in a house in CT that is approximately 280 square feet. I want to tap into my baseboard and add heat to the room. How do I do this so that the square footage gets recorded with the city? And if I put it in, when will I need to advise the city?
Steve, my guess is that the city where your house is located is already counting that 280 square feet as part of what you're paying real estate taxes on. I'm not sure how Connecticut does it, but in Virginia, the county and city real estate appraisers normally measure all new homes as they near completion. The total square footage they calculate and the land value then determine the real estate tax for that property.
If a home is older, at some point an appraiser does measurements on it to compute the tax bill. When remodeling projects are done that increase livable square footage on a house, the city or county will adjust their real estate taxes accordingly. The building permit office normally passes information on to the treasurer's office that allows them to make accurate adjustments.
In addition, appraisers normally inspect homes within the city or county on a regular basis to ensure records are accurate. The inspection may include asking the homeowner questions about any changes that have taken place in addition to taking new measurements. They also measure and add any outbuildings that have been added since the last appraisal that may have increased the value of the property.
If your sunroom was original to the house or added quite some time ago, the 280 square feet should already be a part of the total square footage the city or county has in their records. Whenever the room was finished with insulation and sheetrock, the building permit pulled should have alerted the real estate department to adjust the value of the home. When applying for a building permit, one of the questions almost always asked is how much the project is expected to cost. The building inspection department often uses this information to determine the cost of the permit and they also pass it on to the treasurer's office.
If all that's being done is running a branch HVAC supply line to the sunroom, there's a chance you may not need a building permit for the project. I suggest checking with your local building department to find out what their policy is for this type of minor modification. As far as ensuring that the 280 square feet are included in the city or county's house appraisal, you should be able to verify that with a quick call to their real estate tax office. I'm sure they will be more than happy to add it if by chance the space has been missed.