1. Inspect the glass of the windows. Check for cracked or broken glass which can allow heat to leak out in winter. Get quotes from professionals to remove and replace cracked or broken glass in windows.
2. Check the window frames. Glass is held in place by rubber seals. Window seals crack and deteriorate over time. If the seals have deteriorated there will be a leak for either air or water. The window may have to be removed by a professional. For painted window frames, determine if it is time to paint the frames to protect the wood.
3. Inspect double or triple-pane windows for moisture or condensation between the panes of glass. The space between panes of glass in windows is usually filled with gas to provide extra insulation. Moisture between the panes means that the seal between the panes is broken, decreasing the insulation value of the window. In these cases the seal should be replaced.
4. Check the window casings or frames where they meet the wall and look for cracks. Use window caulking to create an airtight seal and to prevent moisture from getting into the window.
5. Check the weather stripping found in the groove of the window frame. It is easy to remove and replace if it looks cracked, broken, or has pieces missing. Take a piece to to a hardware store or window shop to match, along with the total length you are going to need.
6. Check window locks and latches. This serves 2 purposes – keeping the window properly sealed, and more importantly keeping your home secure. Tighten loose locks and latches and replace broken ones.
7. Invest in storm windows in cold climates or areas subject to storms. When installing storm windows check to makes sure that seals and weather stripping are in good shape.
8. Line windows in colder weather with window plastic to help protect window seals and frames and to help keep heat inside. Consider installing window treatments with shades and curtains to get extra RV protection while still being decorative.