I have a split system in my 2 story 1200 ft townhouse in wake county NC. Gas furnace was replaced in late 2010, AC system was left alone (12 year old goodman). I just got a quote for a new AC system and was told due to code changes, any new HVAC equipment in 2 story houses in NC have to have zoning equipment installed at the same time or it won't pass inspection. Quoted me $$$$ for the zoning equipment. Is this a scam?