I suppose it can vary from state to state, but I believe that it is only considered a commercial activity if the property in question is being used to supply GOODS or SERVICES that can be purchased from the location, or if MANUFACTURING is taking place at the location or you are WAREHOUSING materials for production (mass) on the property. If the house is zoned for non-commercial use only, as in being used as a DWELLING for people to LIVE IN...it's not considered commercial. It would be a single dwelling unit or a multiple family dwelling if a duplex, triplex or apartment. Likewise, I've run my own business out of my own home, using a HOME OFFICE. I did all of my office work from the home office and so could write a portion of it off on my taxes. I went to my clients, they did not come to me; and my business partner at the time was working out of HIS own home office also leaving to visit clients...so while we provided a service, made phone calls and negotiated off of the home office phone, there were no other employees coming TO our houses, nor were there clients coming to the houses. Choosing to rent a room, take in roommates, or renting the whole house out...should not cause it to come under COMMERCIAL zoning laws. Double check with a local attorney (remember most will see you for about 15 to 30 minutes for free) or check with a local real estate agent for possible rules as they apply to YOUR AREA/State.

Thanks Redhawk, what is your profession?