Cash incentives from Energy Trust of Oregon and any available tax credits may help offset the initial cost. In addition, building improvements may qualify for the Oregon Energy Loan Program offered by the Oregon Department of Energy.
When to replace windows and add insulation
- Excess window moisture is leading to damaging mold, mildew and dry rot.
- Conditioned spaces are drafty in winter or too warm in summer.
- Heating and cooling costs are excessive.
- You are planning to remodel or expand.
- You are renovating or conducting maintenance, such as re-roofing.
- The space is unoccupied.
Boost insulation for added comfort and savings
Insulation is rated by its R-value. The higher the number, the better it will keep heat from entering or escaping. Determining how much insulation to install depends on how much is in place, the building’s structure and accessibility to building cavities. In new construction, insulation and high-performance windows are critical parts of the integrated building design.
Insulation comes in various forms:
| Batts |
| Material: |
Fiberglass or rock wool |
| Where used: |
Between joists in ceilings, walls and floors |
| R-value: |
About R-3.2 per inch of thickness |
|
| Rolls |
| Material: |
Fiberglass |
| Where used: |
Ceilings, attic floors |
| R-value: |
About R-3.2 per inch of thickness |
|
| Loose fill |
| Material: |
Fiberglass, rock wool, cellulose |
| Where used: |
Blown in ceilings and wall cavities |
| R-value: |
R-2.2 to R-3.6 per inch of thickness |
|
| Foams |
| Material: |
Polyurethane foam, soy-based and other environmentally friendly materials |
| Where used: |
Blown in wall cavities, ceilings and floors |
| R-value: |
About R-3.5 per inch of thickness |
|
| Rigid foam |
| Material: |
Expanded polystyrene, extruded polystyrene or similar material |
| Where used: |
Exterior walls, basement, foundation and crawlspace walls, concrete slabs and cathedral ceilings |
| R-value: |
R-4 to R-7 per inch of thickness |
|
Frame your energy savings
Window energy-efficiency is rated by U-factor — the lower the U-factor, the more efficient the window. Higher rated window systems reduce energy use with improved glazing, window frames, special coatings, low-conducting gas between panels, improved thermal breaks and improved edge sealing.
Today’s newer windows have frames of wood, aluminum clad wood or vinyl that do not conduct heat or cold. They offer the same low maintenance as aluminum frames with improved energy-efficiency. Spacers made of vinyl rubber between panes help prevent the transfer of heat and cold. Some of the more common commercial window options include:
| Window film |
| Thin layers of polyester or metallic coatings that limit the amount of solar gain and loss in a building |
| U-factor: |
Varies — often used as short-term, inexpensive solution |
|
| Standard double-pane insulated glass |
| Two panes of glass with air space between |
| U-factor: |
0.48 |
|
| High-performance windows |
| Double pane with insulating spacer and low conducting frames, such as wood or vinyl, with thermal breaks |
| U-factor: |
0.33 to 0.30 |
|
| Low-e coatings |
| Thin coating of metal on one pane of sealed multipaned window, blocking up to 98 percent of ultraviolet radiation from sun |
| U-factor: |
Varies |
|
| Gas-filled multipane |
| Low-conductive gas, such as argon, between double or triple panes of glass |
| U-factor: |
Varies, but can improve performance of a low-e window by 15 to 20 percent |
|
| Dynamic glazing (“smart” windows) |
| Glass changes from transparent to dark by changes in light, temperature or voltage, such as electrochromic |
| U-factor: |
Varies |
|