The Quick Answer: If your Colorado home feels drafty, the culprit is usually a combination of three factors: Failed Window Seals  (allowing cold air to bypass the glass), Worn Weatherstripping  on exterior doors (common in dry climates where rubber cracks), or Poor Insulation  in the "Rim Joist" (where the house frame meets the foundation). To pinpoint the leak, perform the "Candle Test" on a windy day: if the flame flickers near the window frame, you have an air leak. If th