Charlotte's temperature swings (20s in winter, 90s+ in summer) make energy-efficient windows a worthwhile investment. Full-home window replacement typically costs $10,000-$30,000+ depending on window count and quality. Low-E glass with argon fill is recommended for Charlotte's climate. Many Charlotte homes built in the 1990s-2000s are now reaching the age where original windows need replacement.
Charlotte's cooling load makes solar heat gain coefficient the number that matters most, more than U-factor. West- and south-facing elevations benefit from lower SHGC glass; using a single spec for the whole house leaves comfort and energy savings on the table.
Installation method changes both cost and result. Insert (pocket) replacements keep the existing frame and cost less but shrink glass area slightly. Full-frame replacement removes the frame down to the rough opening, allows flashing and insulation to be corrected, and is the right call on homes with any history of water intrusion around openings.
Duke Energy periodically offers efficiency incentives, and window manufacturers run seasonal promotions in the slower winter months. Bidding a Charlotte window project in December or January frequently produces better pricing and faster scheduling than doing it in spring.